COVID-19: Vaccines

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This resource is revised often and new content is added regularly to guarantee that the latest evidence and regulatory recommendations are included. The CEP is committed to ensuring this information is accurate and up to date.
Last reviewed: April 12, 2021
Last updated: April 16, 2021

COVID-19 vaccine authorization

Health Canada has authorized a number of COVID-19 vaccines for use in Canada after a thorough and rigorous review of the evidence to ensure the vaccines meet the standards of safety, quality and efficacy for authorization in Canada. Health Canada will continue to monitor the safety of the vaccines after they are available.

Key messages

  • Lead by example. Get the COVID-19 vaccine yourself as soon as it is offered to you to protect yourself, your patients, and your community.
  • Advise patients to receive the vaccine. Communication by trusted health professionals about the importance of vaccines is the most effective way to counter vaccine hesitancy. Tell your patients you will get or have already received the vaccine.
  • Be an educator. Be prepared to answer patient questions and address concerns about the vaccine.

Vaccine summary

Efficacy against severe disease and hospitalization

All of the approved vaccines have a high efficacy rate against severe disease. In the clinical trials, efficacy against severe disease was shown to be:

  • Pfizer: 75-100% (after dose 2)
  • Moderna: 100% (14 days after dose 2)
  • AstraZeneca: 100% (after dose 2)
  • Janssen: 85.4% (28 days after dose)
Should I wait to get an mRNA vaccine?

Age is the greatest risk factor for morbidity or mortality from COVID-19. For those above age 65, an mRNA vaccine may offer the greatest protection.

For those under age 65 who are at risk from COVID-19, the AstraZeneca and Janssen vaccines offer a safe and effective way to reduce risk. Both are extremely effective at reducing hospitalization or death from COVID-19. AstraZeneca may reduce transmission as well, and the Janssen vaccine trial showed high efficacy against the B.135 and P.2 variants. Waiting an uncertain amount of time for an mRNA vaccine may not be desirable compared to getting excellent protection right away from any serious complications of COVID-19.

If I get 1 dose of the AstraZeneca or Janssen vaccine, can I “top up” with an mRNA vaccine?

We don’t know yet what the effect of a “mix and match” approach would be. It’s not recommended right now, as the effect on safety and efficacy of immune protection is unknown. It may be possible to get an mRNA vaccine after a full course of the AstraZeneca/Janssen vaccine, but there is little data to inform this decision at this time.

Click on the sections below to get started:

Vaccine rollout in Ontario New

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Updated Dose delivery schedule

As of April 14, 2021, Ontario has received 2,945,085 doses of the Pfizer-BioNTech vaccine, 1,007,000 doses of the Moderna vaccine, and 900,800 doses of the AstraZeneca vaccine (4,852,885 doses total). Amounts may fluctuate, and the numbers will be updated as quantities and timing of deliveries are confirmed.

Ontario expects to receive the following number of doses in the coming weeks:

Pfizer-BioNTech

  • April 12 and 19: 395,460
  • April 26: 396,630
  • May 3, 10 and 24: 398,970
  • May 17: 400,140

Moderna

  • April 19: 448,400

AstraZeneca and Janssen

  • TBD

For upto-date delivery numbers, see:

Vaccine distribution

Ontario is now in Phase 2 of the province’s three-phase vaccination plan. Throughout the phases, vaccines will be administered to different groups at a mix of mass vaccination clinics, pharmacies, primary care, site-specific clinics, mobile teams/sites, hospital clinics and public health units. Vaccine delivery in each region will vary (see Local vaccine rollout).

Phase 1: High-risk populations
When:

December 2020 – March 2021*

Who:
  • staff, essential caregivers and any residents that have not yet received a first dose in:
    • long-term care homes
    • high-risk retirement homes
    • First Nations elder care homes
  • alternative level of care patients in hospitals who have a confirmed admission to a long-term care home, retirement home or other congregate care home for seniors
  • health care workers identified as highest priority, followed by very high priority (including primary care), then high priority; see COVID-19: Guidance for Prioritizing Health Care Workers for COVID-19 Vaccination (MOH, February 9, 2021))
  • Indigenous adults in northern remote and higher risk communities (on-reserve and urban), followed by all other Indigenous adults
  • adults 80 years of age and older
  • staff, residents and caregivers in retirement homes and other congregate care settings for seniors (e.g., assisted living)
  • adult recipients of chronic home care
Phase 2: Mass delivery
When:

April – June 2021*

Who:
  • adults age 60-79, with regional age-based eligibility determined by public health units
  • adults turning 55 or older in 2021 (via participating pharmacies and primary care settings)
  • adults living in COVID-19 hot spot communities
    • adults age 50 or older living these hot spot communities
    • people age 18 or older in targeted high-risk settings as supply allows (via mobile clinics and pop-up centres)
    • select education staff, starting with those who provide direct support to students with complex special education needs and educators in hot spot postal codes in Toronto and Peel
    • Black and other racialized communities
  • adults age 50 or older living in these hot spot communities
  • caregivers in select congregate care settings
  • individuals with health conditions and their caregivers
  • essential frontline workers who cannot work from home

 

See Ontario’s COVID-19 vaccination plan (Government of Ontario) for more detailed information about who is included in each of these groups, including the list of hot spot postal codes.

Phase 3: Steady state
When:

July 2021 and beyond*

Who:

Remaining Ontarians age 16 or older who wish to be vaccinated

Local vaccine rollout

Public health units (PHUs) will lead local vaccination distribution in partnership with health and municipal sectors, with hospitals continuing to lead vaccination of hospital-based physicians and healthcare workers. PHU-led vaccination will include a combination of mass vaccination sites, mini mass vaccination sites, mobile teams, and pharmacies.

People age 70 or older

All people age 70 or older are eligible for vaccination through mass vaccination clinics. In some public health units, people age 60-69 are also eligible.

How to book

Depending on their location, eligible individuals can book appointments through provincial or regional online booking tools and call centres. See How to book a COVID-19 vaccine (Government of Ontario) to find the age eligibility and booking system in your public health unit.

People age 55 or older

Depending on their location, people age 55 or older are eligible to get the AstraZeneca COVID-19 vaccine in select pharmacies across Ontario or through their primary care provider.

How to book

Eligible individuals must make an appointment with the pharmacy. See COVID-19 pharmacy vaccine locations (Government of Ontario) to find the closest participating pharmacy.

 

In the following public health units, primary care providers may be contacting eligible individuals to book an appointment and will not be taking appointments by request.

  • City of Hamilton
  • Peel
  • Peterborough
  • Simcoe Muskoka District
  • Toronto
  • Wellington-Dufferin-Guelph
New People in hot spot communities

People age 50 or older in hot spot communities, as identified by postal code, are eligible for vaccination. People age 18-49 in hot spot communities are also eligible, starting in Peel and Toronto.

How to book

Depending on their location, eligible individuals 50 or older can book appointments through provincial or regional online booking tools and call centres. See How to book a COVID-19 vaccine appointment to find the age eligibility and booking system in your public health unit.

 

Individuals age 18-49 can’t book through the provincial booking system. Upcoming mobile and pop-up clinics for this group will be promoted locally by community partners and public health units.

Homebound individuals

Homebound Patients/Clients have medical, physical, cognitive, or psychosocial needs/conditions that inhibits them from visiting a local clinic, pharmacy, or their primary care provider to receive their COVID-19 Vaccination. Furthermore, transportation and other strategies to remedy the access difficulties have been considered but are not available or not appropriate in the person’s circumstances.

How to support vaccination

PHUs and FHTs across Ontario are developing ways to reach homebound patients for vaccination. Contact your local PHU for details.

Click your public health unit below for up-to-date information regarding their current regional vaccination status and vaccination plan:

Vaccination in primary care New

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Rollout in primary care practices

Vaccination in primary care practices and community locations will continue to be rolled out across the province in collaboration with public health units as vaccine supply increases. Primary care providers will be contacting eligible Ontarians aged 55 or older directly to book an appointment for the AstraZeneca vaccine, but will not be taking appointment by request. More details will be communicated as soon as they become available (Government of Ontario, April 1, 2021).

See Local vaccine rollout to access up-to-date information on the current regional vaccination status and vaccination plan in each public health unit.

Prepare to support vaccination

New Offering vaccinations in primary care

Additional resources

Identifying vaccine-eligible patients

Rationale and key messages
  • Even if you’re not vaccinating, the role of primary care providers in identifying and contacting eligible patients is crucial in ensuring patients don’t fall through the cracks.
  • Well-constructed communications about vaccines can help build trust between you and your patients.
  • Most patients who are vaccine hesitant report that their primary care provider’s recommendation is of high value when making the decision to be vaccinated.
Communication strategy
  • Determine how you plan on contacting your patients (email/secure messaging, text/sms, phone, mail). If feasible, consider at least a two-pronged approach. Using a mass email/secure messaging or text/sms campaign requires minimal effort and can yield high results, allowing you to engaging patients that are less accessible.
Identifying eligible populations
Paper-based clinics

OntarioMD is offering training for primary care practices that have been identified by their local public health unit to administer COVID19 vaccinations.

A network of 60+ clinicians who offer free, direct support to assist healthcare providers in selecting and implementing health technologies that will best serve their unique needs.

Provincially funded change management services to support primary care providers with the adoption of virtual care, with the goal of improving timely access to primary care and ensuring that all patients in the region are getting the care they need, when they need it.

EMR-based clinics
Tips for running reports
  • Before running your search review the report format to ensure that the following information will be included in your results to support your communication strategy: home phone number, cell/mobile phone number and email address.
  • If you have 3rd party/EMR add-on that allows you to send communications to patients directly from the EMR, you may have the option to email “all” after running your search(es).
  • If you don’t have a 3rd party/Telus PSS Add-on, export your search results into your preferred form (i.e. csv for excel/pdf for printing).  For more information on how to export your search results see your EMR User guide. Administrative staff may be able to assist in this step.

Conduct patient outreach

  • Use the Local vaccine rollout details table to identify which booking systems are in use by your local PHU(s) and capture this information for your communications, website, etc.
  • Email/secure messaging: Filter your eligibility search results to identify patients with an email address.  Customize this mass communication email template with information specific to your region. See: Vaccination Email Template (CEP, 2021).
    • BCC: If you are using a clinic email and not an 3rd party/EMR add-on, ensure patient privacy by making sure to email all patients under the “bcc.”
  • Text/SMS: Filter your eligibility search results to identify patients with a mobile number.  Consider using mass texting services to connect with patients for information about vaccine appointments and link to local PHU. Use the Local vaccine rollout details table to identify your local PHU.
    • Sample text: “COVID-19 Vaccine Update: We are currently not booking vaccinations. Check [local PHU page] for up-to-date information on local vaccination plans. Please avoid calling in an attempt to schedule vaccinations at this time.”
  • Phone: Filter your eligibility search results to identify patients you plan to call (i.e. those not contacted via email/secure messaging or text/sms). Use the Local vaccine rollout details table to identify your local PHU.
Educate patients
Billing

Educate yourself about the vaccines and common questions patients have

Vaccination logistics

COVaxON

OntarioMD is providing additional training and onboarding on COVaxON (the vaccine registration system) for clinical providers, initially focused on those who are directly involved in vaccine pilots, including support for technical questions that arise throughout the process. You can register for training at OntarioMD. A Clinical Workflow Training recording is also available.

Delivery

  • For information on preparation, administration, storage, stability and disposal, see Vaccine administration.
  • Provide patients with an after-care sheet with information about their vaccine, 2nd dose (if needed) and what to expect in the days after receiving the vaccine.
COVID-19 vaccine after-care sheet
Download print-ready PDFs

If you are interested in including your site’s branding on the patient handout, please contact us at info@cep.health.

Vaccine administration

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Vaccine details at a glance

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  • Janssen COVID-19 Vaccine
    • Janssen COVID-19 Vaccine Patient Medication Information Handout (English)
    • Type of vaccine: COVID-19 Viral Vector-based
    • Date of authorization in Canada: March 5, 2021
    • Authorized ages for use: 18 years of age and older
    • Dose: 0.5 mL
    • Schedule: Single dose
    • Booster doses: No evidence on the need for an additional booster
    • Route of administration: Intramuscular (IM) into the deltoid muscle of the upper arm
    • Primary storage requirements: refrigerated (2 to 8ºC) in the original carton to protect from light. Do not freeze. Once punctured, can store at 2°C to 8°C for up to 6 hours or at room temperature up to 25°C for up to 3 hours.
    • Formats available: Multiple dose vial of 5 doses ( one dose is 0.5 mL)
    • DRUG INTERACTIONS: No interaction studies have been performed
  • AstraZeneca COVID-19 Vaccine
    • AstraZeneca COVID-19 Vaccine Patient Medication Information Handout (English)
    • Type of vaccine: COVID-19 Viral Vector-based
    • Date of authorization in Canada: February 26, 2021
    • Authorized ages for use: 18 years of age and older
    • Dose: 0.5 mL each
    • Schedule: 2 doses, 4-12 weeks apart
    • Booster doses: No evidence on the need for an additional booster after the 2-shot series
    • Route of administration: Intramuscular (IM) into the deltoid muscle of the upper arm
    • Primary storage requirements: refrigerated (2 to 8ºC) in the outer carton to protect from light. Do not freeze. Once punctured, can store 6 hours at room temperature up to 30ºC, or 48 hours in a refrigerator (2 to 8ºC).
    • Formats available: Multiple dose vials of 10 or 8 doses at 0.5 mL each (if low dead volume syringes/needles used, there may be sufficient vaccine remaining to provide an additional dose, only if a full dose can be extracted from a single vial)
    • DRUG INTERACTIONS: No interaction studies have been performed
  • Moderna COVID-19 Vaccine
    • Moderna COVID-19 Vaccine Patient Medication Information Handout (English)
    • Type of vaccine: COVID-19 mRNA
    • Date of authorization in Canada: December 23, 2020
    • Authorized ages for use: 18 years of age and older
    • Dose: 0.5mL dose containing 100 mcg of mRNA
    • Schedule: 2 doses, 28 days apart
    • Booster doses: No evidence on the need for an additional booster after the 2-shot series
    • Route of administration: Intramuscular (IM) into the deltoid muscle of the upper arm
    • Primary storage requirements: -25oC to -15oC in the original carton to protect from light
    • Formats available: Multiple dose vial (5 mL, containing 10 doses of 0.5 mL)
    • DRUG INTERACTIONS: No interaction studies have been performed
  • Pfizer-BioNTech COVID-19 Vaccine
    • Pfizer-BioNTech COVID-19 Vaccine Patient Medication Information Handout (English and French)
    • Type of vaccine: COVID-19 mRNA
    • Date of authorization in Canada: December 9, 2020
    • Authorized ages for use: 16 years of age and older
    • Dose: 30 mcg of mRNA per 0.3 mL (after dilution)
    • Schedule: 2 doses, a minimum of 19 days apart (recommended interval 21-28)
    • Booster doses: No evidence on the need for an additional booster after the 2-shot series
    • Route of administration: Intramuscular (IM)
    • Primary storage requirements: -80°C to -60°C (until expiry) or -25°C to -15°C (for up to 2 weeks)
    • Formats available: Multi-dose vial (6 doses) preservative free
    • Usage limit post-dilution: 6 hours from time of dilution at 2°C to 25°C
    • DRUG INTERACTIONS: No interaction studies have been performed

Administration guidance for all vaccines

  • As with all injectable vaccines, appropriate medical treatment and supervision should always be readily available in case of a rare anaphylactic event following the administration of these vaccines.
  • The vaccines are administered through an intramuscular (IM) injection into the upper arm.
  • If administration of the second dose of the vaccine is delayed, it should be administered as soon as possible within the province’s vaccine rollout plan. For more information on the delay of second doses, see Extended time between vaccine doses.
    • For most vaccines, interruption of a vaccine series does not require restarting the series as delays between doses do not result in a reduction in final antibody concentrations for most multi-dose products.
    • However, maximum protection may not be attained until the complete vaccine series has been administered.
  • The vaccine series should be completed with the same COVID-19 vaccine product.
  • Similar to other immunizations, ask patients to wait for 15 minutes following administration in order to monitor for adverse events, such as anaphylaxis.
  • For patients with a history of anaphylaxis not related to vaccines or injectable medications (e.g., allergies to food, pets), a waiting period of 30 minutes is recommended.
  • Remind patients to continue to practice recommended public health measures for prevention and control of SARS-CoV-2 infection and transmission regardless of receipt of COVID-19 vaccine, due to insufficient evidence on the duration of protection and effectiveness of COVID-19 vaccines in preventing asymptomatic infection and reducing transmission of SARS-CoV-2 (NACI, March 1, 2021).

Timing of other vaccinations

NACI recommends that COVID-19 vaccines not be given simultaneously with other vaccines (NACI, Mar 16, 2021). When scheduling other vaccinations:

Before COVID vaccine

Allow for a period of at least 14 days between other vaccines and the COVID-19 vaccine, so that if an adverse reaction occurs, it isn’t attributed to the wrong vaccine.

After COVID vaccine

Allow for a period of at least 28 days after each vaccine dose of an mRNA or viral vector COVID-19 vaccine before the administration of another vaccine (except in the case where another vaccine is required for post-exposure prophylaxis) due to the elicitation of an inflammatory cytokine response.

Adverse events

If a patient experiences a side effect following immunization, such as hives, swelling of the mouth and throat, trouble breathing, hoarseness, wheezing, high fever (over 40oC), convulsions, seizures, or other serious reactions.

Vaccine specific preparation and storage / stability guidance

Janssen

  • Prior to use, Janssen COVID-19 vaccine may be stored and/or transported at a refrigerated temperature of 2°C to 8°C until expiry date.
  • While it is not a recommended storage or shipping temperature range, Janssen COVID-19 Vaccine is stable for a total of 12 hours at 9°C to 25°C.
  • The vaccine must be stored in the original package in order to protect from light. Do not freeze.
  • Do not discard unpunctured vials prior to the expiration date. As the expiration date approaches, check to see if the expiration date has been extended (see Product Monograph, including patient medication information: Janssen COVID-19 Vaccine for details).
  • Before administering a dose of vaccine, carefully mix the contents of the multi-dose vial by swirling gently in an upright position for 10 seconds. Do not shake.
  • Visually inspect the Janssen COVID-19 vaccine for particulate matter and discolouration prior to administration. The vaccine is a colourless to slightly yellow, clear to very opalescent suspension. The vial should be inspected visually for cracks or any abnormalities. If any of these should exist, do not administer the vaccine.
  • The Janssen vaccine is one dose of 0.5 mL is administered intramuscularly in the deltoid muscle by syringe.
  • A needle length of ≥1 inch should be used as needles <1 inch may be of insufficient length.
  • After first puncturing the vial:
    • Janssen COVID-19 vaccine can be held at 2°C to 8°C for up to 6 hours
    • Or at room temperature (maximum 25°C) for up to 3 hours
    • The vaccine must be discarded if not used within this time
  • The vial must be kept in the original package in order to protect from light during storage. Do not freeze.
  • Janssen COVID-19 vaccine must not be reconstituted, mixed with other medicinal products, or diluted.

Unpunctured Vials

Punctured Vials

  • Once punctured, the vial can be stored:
    • at 2°C to 8°C for up to 6 hours
    • at room temperature (maximum 25°C) for up to 3 hours
  • Discard if the vaccine is not used within this time.

AstraZeneca

  • Each vial contains at least the number of doses stated. When low dead volume syringes and/or needles are used, the amount remaining in the vial may be sufficient for an additional dose.
    • Where a full 0.5 mL dose cannot be extracted, the remaining volume should be discarded. Do not pool excess vaccine from multiple vials.
  • The AstraZeneca COVID-19 vaccine does not contain any preservative.
  • The vaccine can be stored in a refrigerator (2 to 8ºC). Do not freeze the vaccine.
  • After first opening, use the vial within:
    • 6 hours when stored at room temperature (up to 30ºC), or
    • 48 hours when stored in a refrigerator (2 to 8ºC ).
  • The vial can be re-refrigerated, but the cumulative storage time at room temperature must not exceed 6 hours. The vial must be discarded if the total cumulative storage time after opening exceeds 48 hours. The vaccine must be used by the expiration date on the label.
  • AstraZeneca COVID-19 Vaccine must not be reconstituted, mixed with other medicinal products, or diluted.

Unpunctured Vials

  • The AstraZeneca COVID-19 vaccine should be stored in a refrigerator (2 to 8ºC). Do not freeze the vial. Use the product before the expiration date on the vial label.

Punctured Vials

  • Once punctured, the vial can be stored:
    • at room temperature (up to 30ºC) for 6 hours
    • in a refrigerator (2 to 8ºC ) for 48 hours
  • The vial can be re-refrigerated but the cumulative storage time at room temperature must not exceed 6 hours.
  • The vial must be discarded if total cumulative storage time after opening exceeds 48 hours.
  • The vaccine must be used by the expiration date on the label.

Moderna

  • The Moderna COVID-19 Vaccine multiple-dose vial contains a frozen suspension and must be thawed prior to administration.
  • Thaw the required number of vials in refrigerated conditions between 2° to 8°C for 2 hours and 30 minutes. After thawing, let vial stand at room temperature for 15 minutes before administering. Alternatively, thaw at room temperature between 15° to 25°C for 1 hour.
  • Do not refreeze.
  • Swirl vial gently after thawing and between each withdrawal. Do not shake.
  • The Moderna COVID-19 Vaccine must not be reconstituted, mixed with other medicinal products, or diluted.

Frozen vials prior to use

  • The Moderna COVID-19 vaccine should be stored at temperatures of -25ºC to -15ºC. Do not store on dry ice or below -40ºC.

Unpunctured vials

  • Unpunctured vials can be stored refrigerated between 2° to 8°C for up to 30 days prior to first use.
  • Unpunctured vials may be stored between 8° to 25°C (46° to 77°F) for up to 12 hours.
  • Do not refreeze thawed vials.

Punctured vials

  • Once punctured, the vial can be stored at room temperature or refrigerated
  • Punctured vials must be discarded after 6 hours. Do not refreeze.

Pfizer-BioNTech

  • The Pfizer-BioNTech COVID-19 vaccine multiple dose vial contains a frozen suspension and must be thawed and diluted prior to administration.
  • Vials may be thawed in the refrigerator (2°C to 8°C), or at room temperature (up to 25°C).
  • Prior to dilution, the thawed suspension may contain white to off-white opaque amorphous particles. DO NOT SHAKE. Before dilution, the vial should be gently inverted ten times to mix.
  • Sterile 0.9% Sodium Chloride Injection, USP is not packaged with the vaccine and must be sourced separately. DO NOT USE BACTERIOSTATIC STERILE 0.9% SODIUM CHLORIDE INJECTION OR ANY OTHER DILUENT.
  • The contents of the vial must be diluted with 1.8 mL of sterile 0.9% Sodium Chloride Injection, USP to form the Pfizer-BioNTech COVID-19 Vaccine. The vial should be gently inverted ten times to mix.
  • After dilution, one vial contains 6 doses of 0.3 mL. Vial labels and cartons may state that a vial contains 5 doses of 0.3 mL. Health Canada has approved a label change rendering the 5 dose statement outdated.
    • Low dead-volume syringes and/or needles can be used to extract 6 doses from a single vial. If standard syringes and needles are used, there may not be sufficient volume to extract a 6th dose from a single vial.
  • After dilution, the vaccine will be an off-white suspension. Inspect vials to confirm there are no particulates and no discolouration is observed.
  • Visually inspect each dose in the dosing syringe prior to administration. If the visual inspection fails, do not administer the vaccine.
  • Time and date of dilution must be recorded on the vial label. Any unused vaccine must be discarded 6 hours after dilution.
  • Vaccine must be stored between 20°C and 25°C.
  • Strict adherence to aseptic techniques must be followed.

Frozen vials prior to use

  • Vials must be kept frozen between -80°C to -60°C (-112°F to -76°F) or between -25°C to -15°C (for up to 2 weeks).
  • Vials stored at -25°C to -15°C for up to 2 weeks may be returned one time to the recommended storage condition of -80°C to -60°C. Total cumulative time the vials are stored at -25°C to -15°C should be tracked and should not exceed 2 weeks.
  • If an ultra-low temperature freezer is not available, the thermal container in which the Pfizer-BioNTech COVID-19 Vaccine arrives may be used as temporary storage when consistently refilled to the top of the container with dry ice. Refer to the re-icing guidelines packed in the original thermal container for instructions regarding the use of the thermal container for temporary storage. The thermal container maintains a temperature range of -90°C to -60°C (-130°F to -76°F). Storage within this temperature range is not considered an excursion from the recommended storage condition.

Thawed vials prior to dilution

  • Prior to dilution, vials may be thawed and stored in the refrigerator [2°C to 8°C (35°F to 46°F)]. A carton of 25 vials or 195 vials may take up to 2 or 3 hours to thaw in the refrigerator, respectively, whereas a fewer number of vials will thaw faster. Vials may be stored in the refrigerator for up to 5 days (120 hours).
  • Frozen vials may also be thawed at room temperature [up to 25°C (77°F)]. Prior to dilution, vials may be stored at room temperature for no more than 2 hours.
  • During storage, minimize exposure to room light, and avoid exposure to direct sunlight and ultraviolet light.
  • Thawed vials can be handled in room light conditions. Do not refreeze thawed vials.

Vials after dilution

  • After dilution, vials must be stored between 2°C to 25°C (35°F to 77°F) and used within 6 hours from the time of dilution.
  • Any vaccine remaining in vials must be discarded after 6 hours.
  • After dilution, the vaccine vials can be handled in room light conditions.
  • Do not freeze. If the vaccine is frozen, it must be discarded.
  • Use the product before the expiration date on the vial label.

Disposal guidance for all vaccines

  • Any unused vaccine or waste material should be disposed of in accordance with local requirements.

Emerging evidence: specific populations, adverse events and vaccine dosage interval New

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New Vaccine real-world effectiveness and impact on transmission

Efficacy is how well the vaccine works in clinical trials. An efficacy of 95% means that in clinical trials, the vaccine decreased the number of COVID-19 cases by 95% compared to the population that received the placebo injection.

Effectiveness is how well the vaccine protects in the real world. Because effectiveness includes less healthy people, it is usually lower than efficacy. An effectiveness of 95% means that in the real world, the vaccine decreased the number of COVID-19 cases by 95% compared to what we would expect in people who are not vaccinated.

How effective are the vaccines in the real world?

Most current effectiveness data is from Israel, the UK, the US and Canada for the Pfizer and Moderna vaccines. While there is some data available from the UK for the AstraZeneca vaccine, no data is yet available for the Janssen (Johnson & Johnson) vaccine.

Pooled real-world effectiveness for the Pfizer, Moderna and AstraZeneca vaccines is estimated to be (PHO, March 19, 2021):

  • 60-80% for preventing COVID-19 infection 3-4 weeks after receiving a single dose, and >85% after a second dose.
  • 70-90% for preventing severe disease and COVID-19-related hospitalization.
  • 70%-96% for reducing deaths attributable to COVID-19 (mostly Pfizer data).

These estimates vary by vaccine and population (general population, older adults, long-term care residents and health care workers).

Do the vaccines prevent transmission of COVID-19?

Early evidence suggests vaccination is associated with reduced spread in populations, regions, or facilities with higher rates of vaccination or those vaccinated earlier than others, but the precise mechanism of this reduction is still unclear. Real-world evidence also suggests that the Pfizer vaccine prevents asymptomatic infections (PHO, March 19, 2021).

AstraZeneca safety

Why does the AZ guidance keep changing?

It is not uncommon for vaccine guidance to change as real-world data emerges after authorization. This recent change in NACI recommendations does not stem from new data, or from the emergence of any Canadian cases, but rather from the use of the precautionary principle.

Are Health Canada and NACI in disagreement?

Health Canada and NACI have different roles in relation to new vaccines.

Health Canada, as a regulator, authorizes each vaccine for use in Canada according to factors based on clinical trial evidence, and monitors vaccine safety internationally after authorization.

  • Health Canada and the European Medicines Agency (EMA) recently reviewed the available data and concluded that the benefits of the AstraZeneca vaccine outweigh the risks.

NACI is an advisory committee of experts that provides guidance to the Government of Canada on the use of vaccines currently or newly approved for use in Canada and bases its guidance on the available and evolving evidence in a real-world context.

  • Following the precautionary principle, NACI recommended a temporary halt in the use of AstraZeneca in those age groups associated with the development of blood clots (those between 20 and 55) while the safety signal of VIPIT is further investigated (NACI, March 29, 2021).
What is Vaccine-induced Prothrombotic Immune Thrombocytopenia (VIPIT)?

VIPIT is a very rare syndrome of low platelets with unusual clots. Rare instances of VIPIT have been observed following vaccination with the AstraZeneca vaccine in Europe, with associated high case fatality and related serious outcomes (PHAC, March 29, 2021). VIPIT appears to mimic Heparin-induced Thrombocytopenia (HIT), but does not require heparin as a trigger (Ontario COVID-19 Science Advisory Table, March 26, 2021).

These blood clots have two important features:

  • they occur 4 to 20 days after vaccination
  • they are associated with low platelets (tiny blood cells that help form blood clots to stop bleeding)
Populations affected

dentified cases have primarily occurred in women between 20 and 55 years, however cases in men have been reported. Generally, cases occurred between 4 and 20 days after receipt of the vaccine (NACI, March 29, 2021).

As this unusual process is immune-mediated and does not develop through the same process as usual types of bleeding or clotting problems, VIPIT is not more common in people who have had blood clots before; have a family history of blood clots; have low platelets; or are pregnant. (Ontario COVID-19 Science Advisory Table, March 26, 2021).

What is the incidence rate?

The rate of VIPIT internationally is difficult to confirm, as there is no central data source. Less than 40 cases have been reported worldwide, out of tens of millions of doses delivered. On March 18, 2021, the EMA estimated an incidence rate of approximately 1 per 1,000,000 people. A higher rate of 1 per 100,000 was reported by the Paul-Ehrlich Institut in Germany (NACI, March 29, 2021); however, this is still indicative of a very low risk. Medical experts have made the comparison in the media to the well-known higher risk of developing blood clots through the use of birth control pills or long-distance air travel.

NACI estimates the case fatality of VIPIT as approximately 40%, but notes that widespread awareness and early treatment may decrease this rate (NACI, March 29, 2021).

Any evaluation of risks and benefits of vaccine-induced blood clots must include acknowledgement of the well-established high risk of blood clots caused by COVID-19 itself. Several studies have suggested that 30-70% of people who are admitted into intensive care units with COVID-19 will develop blood clots in the deep veins of their legs or in the lungs, while approximately 25% will develop a blockage in one of the arteries supplying blood to the lungs (GAVI, March 16, 2021).

What about patients who’ve already received the AstraZeneca vaccine?

For those who have already been vaccinated with AstraZeneca:

  • More than 20 days ago: there is no cause for concern.
  • Less than 20 days ago, or those vaccinated moving forward: self-monitor for 20 days, and seek immediate medical attention if you develop any of these symptoms:
    • shortness of breath
    • chest pain
    • leg swelling
    • persistent abdominal pain
    • sudden onset of severe or persistent worsening headaches or blurred vision
    • skin bruising (other than at the site of vaccination)
  • Second doses: Decisions on the type of second dose offered will be determined based on the latest evidence and research. NACI will review evidence as it emerges to provide advice to public health programs on the potential for completing the vaccine series with other vaccine products. For now, patients do not need a second dose for up to 16 weeks from their first dose.

COVID-19 Variants and vaccines

Through increased global monitoring, COVID-19 variants have been identified. Variants of viruses are common and changes to the genetic material of the virus are expected over time.

The COVID-19 Variants of Concern currently identified in Ontario include:

  • B.1.1.7 originating in the United Kingdom
  • B.1.351 originating in South Africa
  • P.1 originating in Brazil

These variants contain multiple mutations, including some in the receptor-binding domain (RBD) of the spike protein. The virus uses the spike protein’s RBD to enter cells, and most vaccines specifically target the RBD, which raises theoretical concerns over vaccine efficacy. RBD mutations include the N501Y and E484K mutations:

Emerging evidence suggests that some variants of COVID-19 may have an impact on the efficacy of approved COVID-19 vaccines, however more research is required (Health Canada, February 1, 2021). Pfizer-BioNTech, AstraZeneca and Moderna are all conducting research to update their vaccines to protect against emerging variants, particularly variant B.1.351 (PHO, February 7, 2021).

Evidence limitations

Most studies on variants and vaccine efficacy test antibodies taken from vaccine recipients to determine their ability to neutralize synthetic spike proteins that are designed to resemble those of the variants. However, neutralization studies may not be an accurate proxy for vaccine efficacy; it is possible for a person with a reduced neutralizing antibody response to be fully immune (PHO, February 7, 2021).

So far, antibodies from vaccine recipients appear to be less effective at neutralizing the spike proteins of variants, with the largest decreases in neutralization observed with the B.1.351 variant (PHO, February 3, 2021; PHO, February 7, 2021). This pattern has been seen using antibodies from Pfizer-BioNTech, Moderna, AstraZeneca, and Johnson & Johnson vaccine recipients (PHO, February 7, 2021). 

A clinical trial evaluating the AstraZeneca vaccine suggested that it provides little protection against mild-moderate disease caused by the B.1.351 variant. However, the sample size in this trial was small, and it did not test the vaccine’s efficacy against severe disease or hospitalization (NEJM, March 16, 2021).

Extended time between vaccine doses

In an effort to vaccinate many people as quickly as possible, cities and countries around the world are making the decision to extend the interval between doses for those vaccines that require 2 shots.

In accordance with NACI, Ontario will allow an interval as long as 4 months between vaccine doses for recipients of the Pfizer, Moderna and AstraZeneca vaccines (MOH, March 19, 2021). 4 months is a maximum interval intended to maximize vaccine supply. If and when more vaccine is available, patients will be invited to get their 2nd dose sooner than 4 months.

Exceptions: At this time, it is recommended that the following populations receive their second doses at the interval indicated in the vaccine’s product monograph (MOH, March 26, 2021):

  • Transplant recipients (including solid organ transplants and hematopoietic stem cell transplants).
  • Individuals with malignant hematologic disorders and non-hematologic malignant solid tumors receiving active treatment (chemotherapy, targeted therapies, immunotherapy), excluding individuals receiving solely hormonal therapy or radiation therapy. Ideally, vaccination should occur at a time when they are most likely to mount immune responses.
Rationale and monitoring

The rationale for the 4-month dosing interval is based on promising single-dose efficacy data; the limited supply of vaccines in Canada; and experts’ understanding of how long immunity typically lasts after one dose of a multiple-dose vaccine.

  • The vaccines are effective after one dose. Pfizer and Moderna showed 92% efficacy after dose 1 in clinical trials, and 70-80% effectiveness after dose 1 in the real world in Canada, Israel, the UK and the US (NACI, March 8, 2021; JAMMI, March 25, 2021).
  • AstraZeneca clinical trials showed better efficacy when delaying the second dose to ≥ 12 weeks, compared with shorter intervals (NACI, March 8, 2021; JAMMI, March 25, 2021). A UK study found real-world effectiveness of AstraZeneca was significantly higher at 81.3% after two standard doses given at an interval of 12 weeks or longer, compared with 55.1% when given less than 6 weeks apart (Lancet, March 6, 2021)
  • In two-dose vaccines used for other diseases, immunity from the first dose is usually strong for 6 months or longer. Even after considering a gradual decrease in immunity over that time, statistical modelling suggests that immunity from COVID-19 vaccines will likely remain strong after 6 months (NACI, March 8, 2021). But a 6-month delay wasn’t needed in Canada given the number of vaccines expected to be available (JAMMI, March 25, 2021).

NACI decided on 4 months as a balance between vaccine supply, and how long they expect immunity to last after one dose. NACI will continue to monitor the effectiveness of the first dose, and the decision to delay the second dose will be continuously assessed based on emerging surveillance and effectiveness data (NACI, March 8, 2021).

Immunocompromised populations

Why has this been in the news?

The authorization of COVID-19 vaccines (Pfizer-BioNTech, Moderna, and AstraZeneca) and release of their clinical trial details has prompted discussion of who may receive the vaccine based on questions about populations that were included and excluded from the clinical trials.

All three of the vaccine trials:

How does this apply to my practice?

Acknowledging the lack of available evidence, due to the risk of COVID-19 a number of professional organizations recommend that:

  • Individuals within the authorized age groups with autoimmune conditions, immunodeficiency conditions or who are immunosuppressed (due to treatment or autoimmune disorder) may choose to receive the vaccine after informed counselling and consent if a risk assessment deems that the benefits outweigh the potential risks for the individual.
  • Patients receiving treatments that may affect the immune system should be offered vaccination after counselling and informed consent from their treating providers, including a discussion of their vaccination timing in relation to other treatments or possible treatment modifications.
  • There is currently no evidence to indicate whether disease-modifying anti-rheumatic drugs (DMARDs) should be withheld during COVID-19 vaccination. Risk of disease flare should be considered by the treating provider (NACI, March 16, 2021; MOH, February 12, 2021; CDC, January 6, 202; CRA, December 31, 2020).

Pregnant and breastfeeding individuals

Why has this been in the news?

Pregnant and breastfeeding individuals require special considerations for COVID-19 vaccination. Because they were not included in the Phase III clinical trials, there is no data on adverse outcomes of the vaccines on this patient population at this time, though mRNA and viral vector vaccines are not hypothesized to be a risk to the breastfeeding infant (MOH, March 11, 2021; NACI, March 16, 2021; SOGC, March 12, 2021; OSOG/OMA-OG, 2021).

Taking this into consideration, a number of professional organizations have decided that due to the known health risks of contracting COVID-19, it is recommended that pregnant and breastfeeding individuals should be vaccinated as long as a risk assessment deems that the benefits outweigh the potential risks (MOH, March 11, 2021; NACI, March 16, 2021; SOGC, March 12, 2021; OSOG/OMA-OG, 2021).

How does this apply to my practice?

Key takeaway: For pregnant and breastfeeding individuals in the authorized age group, the choice to receive the vaccine resides with the patient and should be made after informed counseling with their treating healthcare provider or by a healthcare provider familiar with their pregnancy. Providers should document this discussion, but patients do not have to provide the vaccination site with a note from their provider (MOH, March 11, 2021).

Further guidance is available on nuanced cases for this population:

  • For patients who determine pregnancy between vaccine doses:
    • NACI recommends that completion of the series may be delayed until after pregnancy, unless risk factors for increased exposure or severe COVID-19 are present and informed consent for vaccination is obtained (NACI, March 16, 2021).
    • SOGC recommends that decision to give a second dose should be based on the results of an individual risk assessment, and that the pregnancy should not be terminated based on having received the vaccine (SOGC, March 12, 2021).
  • For patients planning a pregnancy:
    • The COVID-19 vaccination series should be completed before pregnancy to help ensure maximal efficacy. There is currently no evidence to guide the time interval between the completion of the COVID-19 vaccine series and conception. In the face of scientific uncertainty, NACI recommends it may be prudent to delay pregnancy by 28 days or more after the administration of the complete two-dose vaccine series of a COVID-19 vaccine (SOGC, March 12, 2021; NACI, March 16, 2021).
  • For patients planning the timing of vaccination during pregnancy:
    • SOGC recommends to wait 14 days after any other vaccine before receiving a COVID-19 vaccine, however because of the pandemic simultaneous or closer interval of administration may be considered. The SOGC also recommends that after receiving a COVID-19 vaccine dose, where possible to wait 28 days before receiving any other vaccine, unless a vaccine is required urgently (SOGC, March 12, 2021).
    • SOGC recommends that time-sensitive interventions such as administration of anti-D immunoglobulin and blood products should not be delayed on account of recent COVID-19 vaccination and could be given simultaneously (SOGC, March 12, 2021).
  • For patients impacted by limited vaccine supply:
    • There are no physiologic reasons to anticipate that the effect of delaying the second dose of the COVID-19 vaccine would be different for a pregnant individual compared to a non-pregnant individual. Pregnant individuals may resume their vaccine series the same as the non-pregnant population in situations of supply chain interruptions (SOGC, March 12, 2021).
Emerging evidence
  • Pfizer and BioNTech recently announced that the first participants were vaccinated in a “global Phase 2/3” study to evaluate the safety and efficacy of their vaccine in preventing COVID-19 in healthy pregnant individuals 18 years of age and older. The trial will include approximately 4,000 participants and the vaccine will be administered between 24 to 34 weeks of gestation (Pfizer, February 18, 2021; Johns Hopkins Center for Health Security, February 19, 2021).
  • New research provides evidence that seropositive pregnant individuals can transfer SARS-CoV-2 antibodies to their fetus via the placenta, based on IgG antibodies detected in umbilical cord blood (JAMA Pediatrics, January 29, 2021). More recently, preliminary non peer-reviewed studies and a single case study support the notion that this may also be true in vaccinated pregnant individuals, with SARS-CoV-2-specific antibodies present in both breast milk and cord blood (Johns Hopkins Center for Health Security, March 23, 2021). More evidence and research from high quality studies is needed.

Adverse events and allergic reactions

Why has this been in the news?

International safety monitoring of the Pfizer-BioNTech, Moderna, and AstraZeneca vaccines has identified a small number of cases of anaphylaxis after the vaccine. Information is still emerging regarding the newly approved Janssen vaccine.

  • Out of all the vaccine doses administered in Canada up to April 9th, the rate of serious adverse reaction (including anaphylaxis) is 0.006% (Health Canada, April 9, 2021).
  • In the UK, 20.6 million first doses of the AstraZeneca vaccine, 11 million first doses of the Pfizer vaccine, and around 5.4 million second doses (mostly Pfizer) have been administered with a rate of 3-6 reported adverse events (serious and non-serious) per 1,000 doses. (Weekly Summary, Government of the UK, April 15, 2021)
  • As millions of doses have been given worldwide, the Canadian Society of Allergy and Clinical Immunology (CSACI) identifies the risk for serious allergic reaction as low (CSACI, March 15, 2021).
How does this apply to my practice?

With any vaccine, the potential for allergic reactions exists. Currently, Health Canada does not recommend receipt of any vaccine for the following populations:

  • Persons with proven immediate or anaphylactic hypersensitivity to any component of the vaccine or its container, including polyethylene glycol.
  • Individuals with a history of anaphylaxis after previous administration of the vaccine.

AstraZeneca and Polysorbate 80

Though patients allergic to PEG may also be allergic to polysorbate 80, unless the patient has a known allergy to polysorbate 80, this should not be a contraindication to receiving the AZ vaccine. BCCDC recommends the following practice:

  • For individuals with suspected hypersensitivity or non-anaphylactic allergy to COVID-19 vaccine components, consultation with an allergist is advised. If there is a specific concern about a possible allergy to a component of the COVID-19 vaccine being administered, an extended period of observation post-vaccination of 30 minutes may be warranted; alternately, the vaccine can be administered in an emergency room setting, also with a prolonged observation period (BCCDC, March 2021).

Ensuring patient confidence in vaccines New

Jump to concerns/questions related to:

PrOTCT PLAN for the COVID-19 vaccine discussion

As a primary care provider, you are the key to a successful COVID-19 vaccination campaign. These evidence-based responses to common questions will help you in your role as a community ambassador to promote widespread vaccination.

In all patient encounters, communicate that you and the members of your healthcare team have already gotten or are planning to get vaccinated.

“What do you think of the new vaccine(s)? Do you think I should get it? Is it safe?”

When patients ask these questions, it may be tempting to dive into answering. This framework will help approach these conversations thoughtfully to achieve a positive, effective interaction that builds trust while sharing important information.

Understanding vaccine hesitancy in Black communities

Understanding vaccine hesitancy in Indigenous communities

For Ontario providers

Use the following billing codes when counselling your patients about COVID-19 vaccine(s)/hesitancy:

  • K080, 081, 082 (telephone/video)
  • K013 (in person)

Addressing patient questions about…

The AstraZeneca vaccine

There is no overall increased risk of developing a blood clot after receiving any of the approved COVID-19 vaccines, including the AstraZeneca vaccine. However, the AstraZeneca vaccine is associated with extremely rare cases of blood clots that are associated with low blood platelets, such as cerebral sinus vein thrombosis (CSVT) blood clots in the brain. These cases represent a small fraction of the tens of millions of doses delivered. While the cases are concerning enough to need investigation, it’s important to remember that the risk is very small, especially compared to the proven high risk of blood clots associated with COVID-19 infection.

One group in the AstraZeneca trials received only a half-dose of vaccine in their first shot. This mistake was due to a manufacturing issue and was quickly corrected.

COVID-19 risk and transmission

  • COVID-19 is much more serious than the flu. In Canada, the flu kills roughly 3,500 patients per year. In less than a year, COVID-19 has killed 6 times that many.
  • COVID-19 is very contagious and can cause serious illness. More than 23,200 Canadians and over 556,000 Americans have died of COVID-19.
  • Even if a young and healthy person does not die of COVID-19 infection, they may have long term complications from COVID-19, affecting multiple organ systems. Long-term effects include memory loss, fatigue, body aches, unexplained breathing difficulties, and damage to the lungs and heart. Clinics have already been set up to support the many COVID-19 patients who, although they are no longer infected, cannot go back to work or live a normal life.
  • Even if a young and healthy person does not develop severe COVID-19 infection, you may still pass on the virus to someone who will. If you are vaccinated, you’re helping protect the people around you.
  • Vaccination is the only way to end this pandemic. I and all the members of the healthcare team around you have gotten/will be getting immunized. You can protect yourself, your loved ones, and your community by getting vaccinated.

For more information, see Emerging evidence: Prolonged symptoms of COVID-19 (CEP, 2020)

Even if you had COVID-19 in the past, it is uncertain how long the antibodies will last. You should still get the vaccine to protect yourself and others.

  • The information on this is still developing. At this time, we know that it typically takes a few weeks for the body to develop immunity after vaccination. Therefore, it is possible that a person could be infected with the virus that causes COVID-19 just before or just after vaccination and then get sick because the vaccine did not have enough time to provide protection.
  • That being said, we also know that the vaccines protect most vaccinated people from getting sick with COVID-19. For those who still get sick, they appear to get a milder case. However, studies are ongoing as to how the vaccine affects how contagious infected people are.
  • It is important to continue public health measures of distancing and masking even after vaccination, until scientific experts say it is safe to stop.

Regular exercise and healthy eating can improve your immune system and overall health. But neither can cause your body to produce the antibodies and white blood cells that specifically protect you from COVID-19. Your immune system needs to be trained to produce these, and all approved COVID-19 vaccines help your immune system do this, regardless of the type of vaccine (e.g., mRNA, viral vector, etc.).

There is no evidence that homeopathic treatments can prevent COVID-19 or any other infections (Health Canada, 2019).

mRNA vaccines

The purpose of all COVID-19 vaccines is to imitate the virus without making you sick. That way, your immune system can recognize the COVID-19 virus and stop future infections.

mRNA is something that your cells naturally use, every second of every day. mRNA is the recipe that tells your cells how to make proteins.

A COVID-19 mRNA vaccine has mRNA that tells your cells how to make the “spike protein” found on the outside of the COVID-19 virus. This spike protein cannot make you sick.

Your immune system “reads” the spike protein that our cells made, and builds antibodies and white blood cells to fight it. Then if you are infected with COVID-19, your immune system will recognize the spike protein that covers each virus, and can fight off the infection.

Your body quickly destroys the vaccine after making spike proteins. It does not stay in your body for long and does not make any long-term changes, other than helping you build your antibodies and white blood cells.

No. mRNA vaccines cannot change your DNA. Human beings do not have the enzymes to convert RNA into DNA. The vaccine doesn’t contain those enzymes either. In fact, our cells have enzymes that destroy the mRNA after the protein is made – which is why the vaccine doesn’t stay in your body for long.

Viral vector vaccines

The purpose of all COVID-19 vaccines is to imitate the virus without making you sick. That way, your immune system can recognize the COVID-19 virus and stop future infections.

A COVID-19 viral vector vaccine has a piece of DNA (a gene) that tells your cells how to make the “spike protein” found on the outside of the COVID-19 virus.

In order to get the spike protein DNA into your cells, the DNA is placed in a hollow, harmless virus that is not COVID-19. This virus is called a viral vector, and it cannot make you sick.

Once in your cells, the DNA tells your cells how to make the spike protein. The spike protein cannot make you sick.

Your immune system “reads” the spike protein that your cells made, and builds antibodies and white blood cells to fight it. Then if you are infected with COVID-19, your immune system will recognize the spike protein that covers each virus, and can fight off the infection.

Your body quickly destroys the vaccine after making spike proteins. It does not stay in your body for long and does not make any long-term changes, other than helping you build your antibodies and white blood cells.

No. Viral vector vaccines cannot change your DNA. Human beings do not have the enzymes to insert the vaccine DNA into our DNA. The vaccine doesn’t contain those enzymes either.

For those under age 65, the AstraZeneca and Janssen vaccines offer a safe and effective way to reduce risk. Both are very effective at preventing serious illness from COVID-19. AstraZeneca may reduce transmission as well, and the Janssen vaccine trial showed high efficacy against some of the variants. Since we don’t know when mRNA vaccines might be available for those under 65, I’d recommend getting the good protection of the AstraZeneca or Johnson & Johnson vaccine by taking it when it’s offered to you. Researchers are looking into “boosting” these vaccines with an mRNA follow-up dose later on.

We don’t know yet what the effect of a “mix and match” approach would be. It’s not recommended right now, as the effect on safety and efficacy of immune protection is unknown. It may be possible to get an mRNA vaccine after a full course of the AstraZeneca/Johnson & Johnson vaccine, but there is little data to inform this decision at this time.

Special populations and contraindications

  • The Pfizer-BioNTech, Moderna, AstraZeneca and Johnson & Johnson vaccine have not been tested in pregnant individuals, so more studies are needed. However, there were individuals included in the Pfizer-BioNTech and Moderna studies who found out they were pregnant after having had the vaccine and have not had any adverse events so far.
  • There is also currently no scientific evidence that any of the COVID-19 vaccines can affect fertility. These rumours originally began on social media in the form of false reports claiming that the spike protein on the coronavirus was the same as another spike protein called syncitin-1 that is involved in the growth and attachment of the placenta. The false reports said that getting the vaccine would cause an individual’s body to fight this different spike protein and affect their fertility. However, the two spike proteins are actually completely different.
  • Getting the COVID-19 vaccine will not affect the fertility of pregnant individuals or those seeking to become pregnant, including through in vitro fertilization methods.
  • However, the possible harms of COVID-19 infection are well-known. Let’s discuss the benefits and risks and come to a decision together.

For more information see our Top Resources.

Health Canada, Pfizer-BioNTech, Moderna, AstraZeneca, and Johnson & Johnson do not currently recommend administering the vaccines to children. Children often need a different dose than adults and may show stronger immune reactions.

However, as the Pfizer-BioNTech trial collected some limited data was collected on children 12-15, Health Canada has stated that children in this age group may be given a full course of the Pfizer-BioNTech vaccine only if:

  • they are at very high risk of severe outcomes of COVID-19 due to a pre-existing medical condition known to be associated with increased risk of hospitalization or mortality, and
  • are at increased risk of exposure (e.g., due to living in a congregate care facility), and
  • if a risk assessment deems that the benefits outweigh the potential risks, and
  • if informed consent with the individual and the parent or guardian includes discussion about the insufficiency of evidence on the use of COVID-19 vaccines in this population.

For references and further information, see our Top Resources.

All COVID-19 vaccines are safe and effective for older people. Getting the vaccine is an important step to help prevent becoming sick with the virus.

  • For the Pfizer-BioNTech vaccine, efficacy in adults 65 and over is 94.7%.
  • For the Moderna vaccine, efficacy in adults 65 and over is 86.4%.
  • For the Johnson & Johnson vaccine, efficacy in adults 60 and over is 66.2%.
  • For the AstraZeneca vaccine, there is limited information for adults 65 and older. Recent studies show that the vaccine can reduce the risk of COVID-19 in this age group similarly to how it does for people younger than 65 at 59.9% efficacy.

For references and further information, see our Top Resources.

Serious adverse events and anaphylaxis are very rare with the COVID-19 vaccines, occurring in only 0.006% of doses given. Unless you have a history of allergic reaction to components of the vaccine, or to the first dose of the vaccine, Health Canada recommends vaccination.

It is always advised to wait at least 15 minutes after receiving a vaccine, since an allergic reaction or anaphylaxis is always a possible reaction to any medication or vaccination. For those with a history of allergies, even to food, pets or other non-medical causes, waiting 30 minutes after receiving a vaccine is recommended.

There are many vaccines currently under development. Some patients may be allergic to an ingredient in one, but not another. On this site you can also review the vaccine ingredients in non-medical terms for the Pfizer-BioNTech, Moderna, AstraZeneca and Johnson & Johnson vaccines learn more about propylene glycol.

For references and further information, see our Top Resources.

It is important that new vaccines be tested in diverse populations to ensure that they are safe and effective for everyone. All COVID-19 vaccine trials included people of colour who were both racially and ethnically diverse. Collectively, the trial participants included those identifying as Black, American Indian/Alaska Native, Asian, Native Hawaiian/other Pacific Islander, Hispanic/Latino and multiracial.

For references and further information, see our Top Resources.

Yes, you can take all of the approved vaccines. None of the approved vaccines in Canada contain live viruses, and neither do any of the vaccines that Canada has purchased but not yet approved.

For more information on the different types of COVID-19 vaccines, see Types of COVID-19 vaccines.

Vaccine efficacy

Efficacy means how well the vaccine works in clinical trials. An efficacy of 95% means that in clinical trials, the vaccine decreased the number of COVID-19 cases by 95% compared to the population that received the placebo injection.

But clinical trials are not real-world conditions. For example, people in clinical trials are generally healthy, because researchers do not want to include people who are sick or are taking certain medications.

Effectiveness means how well the vaccine protects in the real world. Because effectiveness includes less healthy people, it is usually lower than efficacy. An effectiveness of 95% means that in the real world, the vaccine decreased the number of COVID-19 cases by 95% compared to what we would expect in people who are not vaccinated.

Information so far suggests that the approved vaccines are very effective in the real world. Clinical trials already showed that all 4 approved vaccines have high efficacy.

No. Vaccinated individuals can still be infected, but vaccination greatly reduces the risk of infection, and reduces the risk of an infection progressing to the more severe form of the disease.

No. An effectiveness of 95% means that the vaccine decreased the number of COVID-19 cases by 95% compared to the population that received the placebo injection. While it is still possible for vaccinated people to get COVID-19, an effectivess of 95% does not mean that 5% of vaccinated people will still get the virus

  • The AstraZeneca clinical trials show protection starts from approximately 3 weeks after receiving the first dose and persists up to 12 weeks. A second dose should be given at a 4-to-12-week interval after the first dose, with evidence that suggests the vaccine increases effectiveness with longer intervals between doses.
  • Pfizer-BioNTech’s clinical trials show that individuals may not be optimally protected until at least 7 days after their second dose of vaccine, given 21 days after the first dose.
  • Moderna’s clinical trials show that individuals may not be optimally protected until after receiving the second dose of the vaccine, given 28 days after the first dose.

References

When scientists measure efficacy and effectiveness, they focus on symptomatic COVID-19 cases. So even with a highly effective vaccine, it is possible for people to develop infections without symptoms. These asymptomatic people can spread COVID-19 to others close to them. Preventing symptomatic cases helps, but in order to better protect against transmission, vaccines must also be able to prevent asymptomatic COVID-19 infections.

Scientists are researching how well the COVID-19 vaccines prevent these asymptomatic cases and how well they prevent transmission. The information we have so far suggests that the Pfizer-BioNTech and Oxford-AstraZeneca vaccines do this well (Preprints with The Lancet, February 1, 2021; Authorea Preprint, February 24, 2021).

The information we have so far suggests that the approved vaccines do this well.

Though we are still learning how many people have to be vaccinated against COVID-19 before most people can be considered protected, it’s currently estimated that 40% – 90% vaccination coverage is required to achieve herd immunity for COVID-19.

References

Vaccines and COVID-19 variants

The Canadian and provincial governments are monitoring cases of new COVID-19 variants in Canada.

Early data suggests that these variants may be more easily transmitted and may impact the severity of disease. There is some evidence to suggest that some variants of COVID-19 may have an impact on the efficacy of approved COVID-19 vaccines.

Additional research is ongoing to learn more about these variants.

It is normal for viruses to change and develop different versions (variants), and there is a risk that certain changes may make COVID-19 more resistant to vaccines. For example, early evidence suggests that vaccines may not be as good at protecting people from the variant originating in South Africa.

Luckily, vaccine companies are doing research to update their vaccines to better protect against variants of concern. The best way you can help reduce the spread of COVID-19 variants is to continue to follow public health guidelines.

Religious beliefs

The Canadian Council of Imams and other Muslim bodies in Canada have stated that they consider the Pfizer-BioNTech, Moderna, and AstraZeneca vaccines to be permissible and will continue to evaluate other approved vaccines (Canadian Muslim COVID-19 Taskforce, 2021).

The Canadian Conference of Catholic Bishops have stated that all approved COVID-19 vaccines are permissible for Catholics. They indicate that Catholics are invited to be vaccinated to contribute to the safety of others (Canadian Conference of Catholic Bishops, March 11, 2021).

Some patients may have questions regarding their religion and receiving COVID-19 vaccines.

Many religious organizations have issued statements that encourage COVID-19 vaccination for the health and safety of individuals and their communities, following the advice of patients’ healthcare providers.

These organizations include:

Answering questions about COVID-19 vaccines: a guide for healthcare providers
Download print-ready PDFs

Preparing for vaccination

While no research has been done to look specifically at whether COVID-19 vaccines are affected by Tylenol or Advil, earlier research has suggested that some drugs may affect immune response to other vaccines. To ensure the vaccine works properly, don’t take Tylenol or Advil immediately before your vaccination appointment. It’s ok to take either of these medications to reduce discomfort in the days after your vaccination.

No. As the vaccines target the immune system, they will not interact with medications such as statins. While certain immunosuppressants may slightly reduce the efficacy of the vaccine, there are no known drug interactions that will cause harm, prevent medications from working, or prevent the vaccine from working. There are some drugs not recommended to be taken with “live” vaccines, however no live vaccines are being considered for approval in Canada.

Vaccine availability and rollout

  • The pandemic – and the lockdowns and public health measures – will not end until the majority of Canadians are vaccinated. To ensure we can vaccinate everyone as quickly as possible, it is important that people access the vaccine the first time it is offered to them.
  • Canada has ordered more than enough vaccines – we have purchased more shots per person than any other country in the world! We will be getting those vaccines delivered over time. The implementation plan of those vaccines is designed to most efficiently end this pandemic. You can feel confident that when you are offered one, it is because it is the right time for you to get it. This is your chance to do your part to end the pandemic and get back to normalcy quickly.
  • If you wait to get vaccinated and get infected in the meantime, you may end up in hospital – which would put more strain on the system than getting the vaccine.
  • If Canadians wait to get the vaccine, the pandemic will keep going – and that includes the restrictions, inability to see family and friends, send your kids to school, travel.
  • If Canadians wait to get the vaccine, more people will die.

For references and further information, see our Top Resources.

Vaccines work because of the immune system’s memory. For most vaccines, the immune system’s memory doesn’t go away in under 4 months. In fact, more time between doses can give the system more time to improve its response.

For COVID-19 vaccines, the government took into account that:

  • The vaccines are effective after one dose. After one dose, Pfizer and Moderna had 92% efficacy in clinical trials, and 70-80% effectiveness in the real world in countries like Canada, the US, and the UK.
  • In AstraZeneca’s clinical trials, the vaccine showed better efficacy when there was more time between the first and second dose.
  • In vaccines against other diseases, protection from the first dose is usually strong for 6 months or more, even if it gradually goes down over that time. But a 6-month delay wasn’t needed in Canada because of the number of vaccines we expect to have available.

There are a few groups who can get their 2nd vaccine dose sooner. These are patients who:

  • Have had an organ or stem cell transplant
  • Have specific tumours and/or blood diseases and are being treated with chemotherapy, targeted therapies, or immunotherapy (MOH, March 26, 2021)

Vaccine development and approval process

  • No steps were skipped in the process of developing, testing, approving, and producing the vaccines.
  • Canada’s best independent scientists have thoroughly reviewed all the data before approving the vaccines as safe and effective for Canadians.
  • The vaccines were produced faster than before not because of skipped steps but because of never-before-seen levels of collaboration and funding around the world invested in this effort. Normally, vaccine clinical trials need 6000-8000 people for the approval process.
    • The Pfizer-BioNTech trial had over 43,000 people.
    • The Moderna trial had over 30,000 people.
    • The AstraZeneca trial had over 11,000 people.
    • The Johnson & Johnson trial had over 44,000 people.
  • Unlike with other vaccines that go one step at a time and then plan the next step, for the COVID-19 vaccines, governments invested in having companies plan all the steps at the beginning and build up their manufacturing capacity right away.

 

For references and further information, see our Top Resources.

 

The use of mRNA and viral vectors for vaccines and treatment of disease has been around for a while – that’s one of the reasons why these vaccines could be developed so quickly. mRNA vaccines have been used in animal models for influenza, Zika, Rabies, CMV and others, and in humans for cancer treatment and cancer vaccine clinical trials. Viral vector vaccine technology has been used for Ebola outbreaks, and a number of studies have focused on viral vector vaccines against other infectious diseases such as Zika, flu, and HIV.

For references and further information, see our Top Resources.

 

  • The pharmaceutical companies manufacture the vaccine and sponsor and conduct the clinical trials, but all vaccine clinical trials must have an independent data and safety monitoring board review the vaccine efficacy and unblind the data.
  • As the trial is completed, Health Canada reviews all safety and efficacy data before allowing the vaccine to be used in the Canadian population.
  • After a vaccine has been approved for use and made available, its safety is continuously monitored by healthcare providers and Canada-wide networks specifically designed for safety. Health Canada monitors national and international vaccine safety reports and will update information about the vaccine as it becomes available.

Health Canada provides ongoing safety monitoring for the vaccines. You can see the most recent data at COVID-19 vaccine safety in Canada (Health Canada).

For references and further information, see our Top Resources.

Side effects

  • The vaccines cannot give you COVID-19 or any other infectious disease. None of the licensed vaccines so far use the live virus that causes COVID-19.
  • It is still possible to contract COVID-19 after you have been vaccinated. Like with other vaccinations, it takes a few weeks for the body to build immunity after vaccination. Someone could be infected with the virus just before or just after vaccination and get sick, because the vaccine didn’t have enough time to provide protection.

References

  • With any of the approved vaccines people can expect to feel a sore arm, a bit of tiredness and a mild headache as the vaccine starts to work. Some people will feel muscle aches, chills, or a mild fever.
  • For more information on how common side effects were in the Pfizer-BioNTech clinical trial, see its Clinical trial details.
  • For more information on how common side effects were in the Moderna clinical trial, see its Clinical trial details.
  • For more information on how common side effects were in the AstraZeneca clinical trial, see its Clinical trial details.
  • For information about AstraZeneca and rare blood clots see questions about the AstraZeneca Vaccine
  • For more information on how common side effects were in the Janssen clinical trial, see its Clinical trial details.

References

  • Among the almost 22,000 vaccinated with the Pfizer-BioNTech COVID-19 vaccine, there were 4 cases of Bell’s palsy. This number of Bell’s palsy cases is consistent with the expected rate in the general population and did not suggest it was caused by the vaccine. Three cases occurred within one month after both doses were completed, and one case occurred later than one month after both doses were completed, and all four patients recovered.
  • More research will be conducted as this was the only “imbalanced” occurrence that happened more in the vaccine arm of the study than the placebo arm.
  • Those with previous history of Bell’s palsy may still take this vaccine.

References

  • Yes. Mild side effects are common for all vaccines.
  • There could be soreness and swelling which for some might be significant (sometimes from shoulder to elbow). In these cases:
    • Use cold compresses over the site.
    • Know that local reactions, even big ones, improve by 48-72 hours. If the reaction worsens at 72 hours or has not disappeared in 5 days, seek medical attention.
    • Even though sometimes this reaction can look like an infection, the risk of skin/local infection from a vaccine needle is very small. These reactions do not need any antibiotics in the first 72 hours.
    • If the swelling progresses rapidly, is associated with breathing problems, or makes you very concerned about an allergic reaction, seek urgent medical attention and/or call 9-1-1.

Vaccine safety and adverse events

Health Canada authorizes vaccines based on a thorough review of the evidence and only if they meet Canada’s safety and quality requirements. To ensure continued safety and quality, Health Canada is investigating the AstraZeneca vaccine and extremely rare cases of blood clots. Until they are certain of its safety, the vaccine is not recommended for people under 55, who are at higher risk of developing this condition.

See COVID-19 vaccine safety in Canada (Health Canada) for up-to-date information on adverse events related to vaccines in Canada.

At this time, no vaccine-related deaths have occurred in Canada. However, the AstraZeneca vaccine is associated with extremely rare cases of blood clots that are associated with low blood platelets. These cases represent a small fraction of the tens of millions of doses delivered. While the cases are concerning enough to need investigation, it’s important to remember that the risk is very small, especially compared to the proven high risk of blood clots associated with COVID-19 infection.

No. “Long COVID” symptoms are caused by the virus, and the vaccines do not contain any virus. Side effects from the vaccine are common and should resolve within a few days.

  • Since the vaccines are new, studies are ongoing to determine how long the immunity lasts or if there are long-term side effects. The long-term data we’re still waiting for is more about long-term efficacy (how long immunity lasts) than long-term safety.
  • It is very unlikely for long-term effects to develop, as these initial vaccines are not live vaccines and side effects most often present in the first few days after vaccination.

Polyethylene glycol (PEG) allergies are rare. PEG is a common ingredient found in many products, and most people use these products without having any allergic reactions.

If you have used any of the following medications without allergies, you are not allergic to PEG:

  • Extra Strength Tylenol, Tylenol EZ tabs, Tylenol Gel Caps
  • Advil Liqui-Gels
  • Benadryl 25 or 50mg pink caplets
  • Laxaday
  • Go-Lytely
  • Reactine 5 or 10mg tablets
  • Enteric coated daily low dose aspirin (81 mg)

To identify PEG on a label, look for:

  • “Polyethylene glycol”
  • PEG followed by a number (PEG-40).
  • PEG followed by a number and then another ingredient name (PEG-20 cocamine)
  • Complex PEG compounds with many slashes, but will always contain “PEG” (BIS-PEG/PPG-16/16 PEG/PPG-16/16 Dimethicone)

Questions specific to Indigenous communities

It’s natural to question the motive as to reasons why Indigenous Peoples are identified as a priority.

Along with healthcare workers and residents of long-term care/retirement homes, Indigenous Peoples have been identified as a priority population because evidence shows they are among those at greatest risk of serious, life-threatening implications if they contract COVID-19.

Moreover, chronic medical conditions with a greater prevalence among Indigenous Peoples such as respiratory disease, heart disease, diabetes, kidney and liver disease, have been found to be at greater risk of more severe outcomes from COVID-19 (IPHCC, 2021).

Types of COVID-19 vaccines New

There are four main categories of COVID-19 vaccines that are under development (GAVI, 2021):

  • Nucleic acid vaccines, which include mRNA vaccines and DNA vaccines
  • Subunit vaccines, which include protein subunit vaccines and virus-like particle (VLP) vaccines
  • Viral vector vaccines
  • Whole virus vaccines, which include inactivated vaccines and live-attenuated vaccines

Different types of vaccines offer different advantages and disadvantages, in terms of how easy they are to manufacture and store, as well as the level of immunity they invoke (GAVI, 2021).

Click for details:

Are there other vaccines of this type available in Canada?

  • No. These are the first mRNA vaccines available in Canada.

Are there COVID-19 vaccines of this type approved by Health Canada?

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • mRNA vaccines contain genetic material from the COVID-19 virus (called mRNA) that gives human cells instructions to make specific COVID-19 proteins.
  • After our cells make copies of the protein, our cells destroy the mRNA.
  • The human immune system learns to recognize these COVID-19 proteins and develops antibodies and white blood cells against them, which provides immunity against COVID-19 in the future.

Are these “whole virus” vaccines?

  • No. mRNA vaccines only contain part of COVID-19’s genetic material (mRNA), and do not contain any of its proteins.

Can these vaccines cause COVID-19 disease?

  • No. mRNA vaccines don’t contain the entire COVID-19 genome or any of its proteins, all of which are necessary for COVID-19 to cause disease.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Immune response is strong as it involves B cells and T cells
    • No live components, so no risk of the vaccine triggering disease
    • Relatively easy to manufacture
  • Disadvantages:
    • Some RNA vaccines require ultra-cold storage
    • Never been licensed in humans
    • Booster shots may be required

Are there other vaccines of this type available in Canada?

  • No. There are no DNA vaccines approved in Canada for diseases other than COVID-19.

Are there COVID-19 vaccines of this type approved by Health Canada?

  • No. There are no COVID-19 vaccines of this type approved by Health Canada at this time.

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • DNA vaccines contain genetic material (DNA) that gives human cells instructions to make specific COVID-19 proteins.
  • The DNA is first inserted into a circular piece of bacterial DNA, which is called a plasmid (these are widely used in genetic engineering).
  • Plasmids are then injected into a person’s muscle. Different vaccines use different approaches to make sure that the plasmid can enter human cells once inside the muscle.
  • Once the plasmid is inside our cells, our cells make copies of the COVID-19 protein.
  • The human immune system learns to recognize these COVID-19 proteins and develops antibodies and white blood cells against them, which provides immunity against COVID-19 in the future.

Are these “whole virus” vaccines?

  • No. DNA vaccines only contain genetic material (DNA) with some of COVID-19’s genes, and do not contain any of its proteins.

Can these vaccines cause COVID-19 disease?

  • No. DNA vaccines don’t contain the entire COVID-19 genome, or any of its proteins, all of which are necessary for COVID-19 to cause disease.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Immune response is strong as it involves B cells and T cells
    • No live components, so no risk of the vaccine triggering disease
    • Relatively easy to manufacture
  • Disadvantages
    • Never been licensed in humans
    • Booster shots may be required

Are there other vaccines of this type available in Canada?

  • Yes, including the SHINGRIX shingles vaccine.

Are there COVID-19 vaccines of this type approved by Health Canada?

  • No. There are no COVID-19 vaccines of this type approved by Health Canada at this time.

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • Subunit vaccines contain pieces of the COVID-19 virus (in this case, pieces of COVID-19 proteins).
  • The human immune system learns to recognize these proteins and creates antibodies, which provides immunity against COVID-19 in the future.
  • Because the COVID-19 proteins cannot infect cells, only part of the immune system (i.e. antibodies) can react to them. Adjuvant medications and/or booster doses may be required.

Are these “whole virus” vaccines?

  • No. Protein subunit vaccines only contain pieces of specific COVID-19 proteins, and do not contain all of its proteins, or any genetic material.

Can these vaccines cause COVID-19 disease?

  • No. Protein subunit vaccines don’t contain all of COVID-19’s proteins, or any of its genes, all of which are necessary for COVID-19 to cause disease.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Well-established technology
    • Suitable for people with compromised immune systems
    • No live components, so no risk of the vaccine triggering disease
    • Relatively stable
  • Disadvantages
    • Relatively complex to manufacture
    • Adjuvants and booster shots may be required
    • Determining the best antigen combination (i.e., mix of protein pieces) takes time

Are there other vaccines of this type available in Canada?

  • Yes, including all HPV vaccines.

Are there COVID-19 vaccines of this type approved by Health Canada?

  • No. There are no COVID-19 vaccines of this type approved by Health Canada at this time.

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • Virus-like particle vaccines contain COVID-19 proteins that are assembled into something resembling a COVID-19 virus, but without COVID-19’s genetic material.
  • The human immune system learns to recognize these COVID-19 proteins and develops antibodies and white blood cells against them, which provides immunity against COVID-19 in the future.

Are these “whole virus” vaccines?

  • No. Although virus-like particle vaccines physically resemble the virus to a degree, they do not contain any of COVID-19’s genetic material, and do not contain all of its proteins.

Can these vaccines cause COVID-19 disease?

  • No. Virus-like particle vaccines don’t contain all of COVID-19’s proteins, or any of its genes, all of which are necessary for COVID-19 to cause disease.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Immune response is strong as it involves B cells and T cells
    • Suitable for people with compromised immune systems
    • No live components, so no risk of the vaccine triggering disease
  • Disadvantages:
    • Relatively complex to manufacture
    • Relatively temperature sensitive, so careful storage necessary

Are there other vaccines of this type available in Canada?

  • No. There are no viral vector vaccines approved for other human diseases in Canada, there are viral vector vaccines available in other countries, such as the Merck Ebola vaccine.

Are there COVID-19 vaccines of this type approved by Health Canada?

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • Viral vector vaccines contain a weakened version of a live virus that is not the COVID-19 virus. This weakened virus (which is often an adenovirus), is called a “viral vector”, and has genetic material from the COVID-19 virus inserted inside it.
  • Once the viral vector is inside human cells, the COVID-19 genetic material gives cells instructions so that they can make specific COVID-19 proteins.
  • The immune system learns to recognize these proteins and develops antibodies and white blood cells against them, which provides immunity against COVID-19 in the future.

Are these “whole virus” vaccines?

  • No. Viral vector vaccines only contain certain genetic material from COVID-19, not the entire genome, and the protein “shell” containing these pieces of genetic material belongs to a different type of virus (e.g., a harmless adenovirus).

Can these vaccines cause COVID-19 disease?

  • No. Viral vector vaccines don’t contain the entire COVID-19 genome or any of its proteins, all of which are necessary for COVID-19 to cause disease.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Immune response is strong as it involves B cells and T cells
    • Well-established technology
  • Disadvantages:
    • Previous exposure to the vector (e.g., adenovirus) could reduce effectiveness
    • Relatively complex to manufacture

Are there other vaccines of this type available in Canada?

  • Yes, including all flu shots (nasal spray is live-attenuated).

Are there COVID-19 vaccines of this type approved by Health Canada?

  • No. There are no COVID-19 vaccines of this type approved by Health Canada at this time.

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • Inactivated vaccines contain whole COVID-19 viruses whose genetic material has been destroyed by heat, chemicals or radiation.
  • These viruses cannot infect cells and replicate, and therefore may be safer than live-attenuated vaccines for those who are immunocompromised.
  • Because the inactivated viruses cannot infect cells, only part of the immune system (i.e. antibodies) can react to them. Adjuvant medications and/or booster doses may be required.

Are these “whole virus” vaccines?

  • Yes, but the virus is not live as its genetic material has been destroyed.

Can these vaccines cause COVID-19 disease?

  • No. Inactivated vaccines cannot cause COVID-19 disease because the COVID-19 genetic material has been destroyed.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Well-established technology
    • Suitable for people with compromised immune systems
    • No live components, so no risk of the vaccine triggering disease
    • Relatively simple to manufacture
    • Relatively stable
  • Disadvantages
    • Booster shots may be required

 

Are there other vaccines of this type available in Canada?

  • Yes, including all MMR and MMRV vaccines.

Are there COVID-19 vaccines of this type approved by Health Canada?

  • No. There are no COVID-19 vaccines of this type approved by Health Canada at this time.

How many COVID-19 vaccines of this type are in the clinical trials stages of development?

How do these vaccines work?

  • Live-attenuated vaccines use a form of the COVID-19 virus that has been weakened in the laboratory, which can still grow and replicate, but causes mild or no illness.
  • Because these are live COVID-19 viruses, they are able to infect human cells, and the human immune system can respond to these viruses almost as well as it does to the “wild-type” virus.
  • The weakened virus enters human cells, and provides instructions so that cells make specific COVID-19 proteins.
  • The immune system learns to recognize these proteins and develops antibodies and white blood cells against them, which provides immunity against COVID-19 in the future.

Are these “whole virus” vaccines?

  • Yes, but the virus has been weakened so that it only produces mild or no illness.

Can these vaccines cause COVID-19 disease?

  • Yes. In very rare cases, the live-attenuated virus may mutate and revert back to a more pathogenic form.

What are some of the advantages and disadvantages of this type of vaccine?

  • Advantages:
    • Immune response is strong as it involves B cells and T cells
    • Well-established technology
    • Relatively simple to manufacture
  • Disadvantages:
    • Unsuitable for people with compromised immune systems
    • May trigger disease in very rare cases
    • Relatively temperature sensitive, so careful storage necessary

Janssen (Johnson & Johnson) viral vector vaccine

Jump to:

The Janssen vaccine showed 66.1% efficacy in preventing SARS-CoV-2 infection and is used both for preventing the occurrence of COVID-19 infection and diminishing the severity of the infection. For information on preparation, administration, storage, stability and disposal, see Vaccine administration.

Clinical trial details

Enrollment
  • 44,325 total participants
  • Note that some participants were excluded from efficacy and safety analyses, therefore not all statistics are based on the total number of participants (44,325). This can contribute to slightly different statistics being reported by different sources.
  • 39,321 total participants were included in the primary efficacy analysis (19,630 in the Janssen COVID-19 Vaccine group and the 19,691 in the placebo group)
  • For the number of patients in each subset, see Janssen COVID-19 Product Monograph (Janssen, March 5, 2021).
Participant demographics

Janssen COVID-19 Vaccine Group

  • 20.3% were 65 years of age or older
  • Were of diverse racial and ethnic backgrounds:
    • White (62.1%)
    • Black or African American (17.2%)
    • American Indian or Alaska native (8.4%)
    • Asian (3.7%)
    • Native Hawaiian or other Pacific Islander (0.3%)
    • Hispanic or Latino (44.8%)
    • Multiracial (5.3%)
  • 39.9% had ≥1 comorbidities* at baseline that increase the risk of progression to severe/critical COVID-19.

Placebo Group

  • 20.4% were 65 years of age or older
  • Were of diverse racial and ethnic backgrounds:
    • White (62%)
    • Black or African American (17.2%)
    • American Indian or Alaska native (8.3%)
    • Asian (3.4%)
    • Native Hawaiian or other Pacific Islander (0.2%)
    • Hispanic or Latino (45.4%)
    • Multiracial (5.5%)
  • 40% had ≥1 comorbidities* at baseline that increase the risk of progression to severe/critical COVID-19.

*Obesity defined as BMI ≥30 kg/m2 (27.5%), hypertension (10.3%), type 2 diabetes (7.2%), stable/well-controlled HIV infection (2.5%), serious heart conditions (2.4%), asthma (1.3%) and in ≤1% of individuals: cancer, cerebrovascular disease, chronic kidney disease, chronic obstructive pulmonary disease, cystic fibrosis, immunocompromised state (weakened immune system) from blood or organ transplant, liver disease, neurologic conditions, pulmonary fibrosis, sickle cell disease, thalassemia and type 1 diabetes, regardless of age.
Time followed

At the time of the final primary efficacy analysis (cut-off date of January 22, 2021), participants had been followed for symptomatic COVID 19 disease for a median of 8 weeks post-vaccination, corresponding to 3,143.7 person years for the Janssen COVID-19 Vaccine and 3,146.7 person years in the placebo group.

Protection

As with any vaccine, vaccination with the Janssen COVID-19 Vaccine may not protect all vaccinated individuals. Even after you have had the vaccine, continue to follow the recommendations of local public health officials to prevent spread of COVID-19.

Efficacy

Vaccine efficacy for the co-primary endpoints against moderate to severe/critical COVID-19 in individuals who were seronegative or who had an unknown serostatus at baseline was 66.9% at least 14 days after vaccination and 66.1% at least 28 days after vaccination. Vaccine efficacy results against moderate to severe/critical COVID-19 are presented in Table 7 in the Janssen COVID-19 Product Monograph (Janssen, March 5, 2021).

Serious side effects

Serious adverse events were experienced by 0.4% of subjects in the vaccine group and 0.6% of subjects in the placebo group. When COVID-19-related SAEs were excluded, 0.4% of participants in both the vaccine group and the placebo group reported an SAE.

Non-serious side effects

Solicited adverse reactions were generally more common in younger than in older age groups. Most adverse reactions occurred within 2 days following vaccination, were mild to moderate in severity, and of short duration (2 to 3 days). Most of the unsolicited adverse events were of Grade 1 or Grade 2 severity, with 0.6% of participants in each group reporting an unsolicited AE of Grade 3 severity. The most common unsolicited AEs occurring within 28 days after vaccination were predominantly reactogenicity events, some of which overlapped with the solicited AEs.

 

Most frequently reported adverse reactions in subjects 18-59 years of age:

  • Injection site pain: 58.6% (vs. 17.4% in placebo group)
  • Injection site erythema: 9.0% (vs. 4.3% in placebo group)
  • Injection site swelling: 7.0% (vs. 1.6% in placebo group)
  • Headache: 44.4% (vs. 24.8% in placebo group)
  • Fatigue: 43.8% (vs. 22.0% in placebo group)
  • Myalgia: 39.1% (vs. 12.1% in placebo group)
  • Nausea: 15.5% (vs. 8.9% in placebo group)
  • Fever: 12.8% (vs. 0.7% in placebo group)

Most frequently reported adverse reactions in subjects ≥ 60 years of age:

  • Injection site pain: 33.3% (vs. 15.6% in placebo group)
  • Injection site erythema: 4.6% (vs. 3.2% in placebo group)
  • Injection site swelling: 2.7% (vs. 1.6% in placebo group)
  • Headache: 30.4% (vs. 22.1% in placebo group)
  • Fatigue: 29.7% (vs. 20.8% in placebo group)
  • Myalgia: 24.0% (vs. 13.7% in placebo group)
  • Nausea: 12.3% (vs. 10.8% in placebo group)
  • Fever: 3.1% (vs. 0.5% in placebo group)

Contraindications and precautions

The Janssen vaccine is contraindicated for:
  • Individuals who have had a severe allergic reaction to any of the medicinal ingredients or any of the other ingredients in this vaccine or any other adenovirus-based vaccines.
  • Vaccination should be deferred in symptomatic individuals with confirmed or suspected SARS-CoV-2 infection, or those with symptoms of COVID-19. To minimize the risk of COVID-19 transmission, symptomatic individuals who arrive at an immunization clinic should be instructed to follow current local public health measures and be encouraged to get tested.
  • Individuals who have received another vaccine in the past 14 days.
  • Individuals outside of the authorized age group (< 18).
Precautions should be taken with:
  • Patients who have a bleeding problem, bruise easily or use a blood-thinning medication.
  • Patients with a history of fainting. Procedures should be in place to prevent injury from fainting and manage syncopal reactions.
  • Individuals who have experienced a severe allergic reaction, including anaphylaxis after any other vaccine injection.
  • Patients who are pregnant or breastfeeding. See Pregnant and breastfeeding women.
  • Patients who are immunocompromised, due to disease or treatment. See Immunocompromised populations

Vaccine ingredients

Viral vector
  • Adenovirus type 26 (recombinant, replication-incompetent human adenovirus)

This is the active ingredient of the vaccine. It is a harmless virus that causes the common cold, which has been genetically modified to contain the instructions your body needs to build antibodies against COVID-19. It has also been modified so that it does not cause infection.

Alcohol
  • Ethanol

This ingredient helps to keep the adenovirus from breaking down.

Acid and base stabilizers
  • Citric acid monohydrate (mild acid)
  • Trisodium citrate dihydrate (mild base)

These ingredients are used to help balance the pH of the vaccine so it is close to that of a person’s body.

Emulsifier
  • Polysorbate 80

This ingredient, which is commonly found in foods and cosmetics, helps to keep the oil-based and water-based ingredients from separating.

Salt
  • Sodium chloride; AND
  • Sodium hydroxide (a base) and hydrochloric acid (an acid), which combine in the vial to make water and sodium chloride (table salt)

Sodium chloride is also known as table salt, and is used to help balance the salt levels in the vaccine so they are close to that of a person’s body.

Sugar
  • 2-hydroxypropyl-β-cyclodextrin (HBCD)

This ingredient helps to keep the vaccine a liquid.

Water
  • Water for injection

Water is used to mix the vaccine ingredients into a liquid that can be injected into the body.

Oxford-AstraZeneca viral vector vaccine New

Jump to:

The AstraZeneca vaccine showed 59.5% efficacy in preventing SARS-CoV-2 infection and is used both for preventing the occurrence of COVID-19 infection and diminishing the severity of the infection. For information on preparation, administration, storage, stability and disposal, see Vaccine administration.

Clinical trial details

Enrollment

Study COV002 (United Kingdom)

Study COV003 (Brazil)

Participant demographics

Study COV002 (United Kingdom)

  • 7.4% were 65 years of age or older
  • 7.55% were from communities of colour
  • 35.9% had 1 or more of the following comorbidities at baseline: BMI 30kg/m2 or higher, cardiovascular disorder, respiratory disease or diabetes

Study COV003 (Brazil)

  • 2.5% were 65 years of age or older
  • 33.5% were from communities of colour
  • 36.5% had 1 or more of the following comorbidities at baseline at baseline: BMI 30kg/m2 or higher, cardiovascular disorder, respiratory disease or diabetes
Time followed

At the time of the interim primary efficacy analysis, participants had been followed for symptomatic COVID-19 disease for a median of 63 days (range: 16-94 days) after the second dose, corresponding to exposure of 921 person-years in the AstraZeneca COVID-19 Vaccine and 925 person-years in the control group.

Protection

Individuals may not be optimally protected until after receiving the second dose of the vaccine.

Efficacy
  • In participants who received two standard doses of the vaccine (SD/SD) or the corresponding control, vaccine efficacy from 15 days-post second dose was 62.1%.
  • Based on an updated analysis (data cut-off December 7, 2020), vaccine efficacy was 59.5% in participants who received two standard doses with the second dose administered 4 to 12 weeks after the first dose.
Serious side effects

Serious adverse events were experienced by 0.7% of subjects in the AstraZeneca COVID-19 Vaccine group and 0.8% of subjects in the control group.

Non-serious side effects

In clinical studies with the vaccine, most side-effects were mild-to-moderate and resolved within a few days. When compared with the first dose, adverse reactions reported after the second dose were milder and reported less frequently. Reactogenicity was generally milder and reported less frequently in older adults (≥65 years old).

 

Most frequently reported adverse reactions in subjects 18 years of age and older:

  • Injection site tenderness: 75.3% (vs. 18.4-78.7% in placebo)*
  • Injection site pain: 54.2% (vs. 4.9-37.1% in placebo)*
  • Fatigue: 62.3% (vs. 21.1-46.2% in placebo)*
  • Headache: 57.5% (vs. 14.3-42.3% in placebo)*
  • Myalgia: 48.6% (vs. 8.5-23.8% in placebo)*
  • Malaise: 44.2% (vs. 6.7-18.5% in placebo)*
  • Fever: 7.95% (vs. 0-0.6% in placebo)*
  • Feverishness: 33.6% (vs. 3.1-9.9% in placebo)*
  • Chills: 31.9% (vs. 2.7-7.6% in placebo)*
  • Arthralgia: 27.0% (vs. 6.6-9.0% in placebo)*
  • Nausea: 21.9% (vs. 3.1-12.1% in placebo)*

Contraindications and precautions

The AstraZeneca vaccine is contraindicated for:
  • Individuals who have had an allergic reaction to a previous dose of the vaccine.
  • Individuals who have had a severe allergic reaction to any of the medicinal ingredients or any of the other ingredients in this vaccine.
  • Vaccination should be deferred in symptomatic individuals with confirmed or suspected SARS-CoV-2 infection, or those with symptoms of COVID-19. To minimize the risk of COVID-19 transmission, symptomatic individuals who arrive at an immunization clinic should be instructed to follow current local public health measures and be encouraged to get tested.
  • Individuals who have received another vaccine (not a AstraZeneca COVID-19 vaccine) in the past 14 days.
  • Individuals outside of the authorized age group (< 18).
Precautions should be taken with:
  • Patients who have a bleeding problem, bruise easily or use a blood-thinning medication.
  • Patients with a history of fainting. Procedures should be in place to prevent injury from fainting and manage syncopal reactions.
  • Individuals who have experienced a severe allergic reaction, including anaphylaxis after any other vaccine injection.
  • Patients who are pregnant or breastfeeding. See Pregnant and breastfeeding women.
  • Patients who are immunocompromised, due to disease or treatment. See Immunocompromised populations

Vaccine ingredients

Viral vector
  • ChAdOx1-S (recombinant, replication-incompetent chimpanzee adenovirus)

This is the active ingredient of the vaccine. It is a harmless virus that causes the common cold in chimpanzees, which has been genetically modified to contain the instructions your body needs to build antibodies against COVID-19. It has also been modified so that it does not cause infection.

Stabilizer
  • Magnesium chloride hexahydrate (salt)
  • Disodium edetate dihydrate (EDTA)
  • Ethanol (alcohol)
  • Sucrose (sugar)

These ingredients are stabilizers that are used to prevent clump formation in the vaccine.

Amino acid (and amino acid salt)
  • L-Histidine
  • L-Histidine hydrochloride monohydrate

These ingredients are used to help balance the pH of the vaccine so it is close to that of a person’s body.

Emulsifier
  • Polysorbate 80

This ingredient, which is commonly found in foods and cosmetics, helps to keep the oil-based and water-based ingredients from separating.

Salt
  • Sodium chloride

This ingredient, also known as table salt, is used to help balance the salt levels in the vaccine so they are close to that of a person’s body.

Water
  • Water for injection

Water is used to mix the vaccine ingredients into a liquid that can be injected into the body.

Moderna mRNA vaccine

Jump to:

The Moderna COVID-19 vaccine showed 94.1% efficacy in preventing SARS-CoV-2 infection and is used both for preventing the occurrence of COVID-19 infection and diminishing the severity of the infection. For information on preparation, administration, storage, stability and disposal, see Vaccine administration.

Clinical trial details

Enrollment
  • 30,351 total participants (15,181 receiving vaccine and 15,170 receiving placebo)
  • Note that some participants were excluded from efficacy and safety analyses, therefore not all statistics are based on the total number of participants (30,351). This can contribute to slightly different statistics being reported by different sources.
  • For the number of patients in each subset, see the Moderna COVID-19 vaccine product monograph (Moderna, February 19, 2021).
Participant demographics
  • 25.3% were 65 years of age or older
  • 36.2% were from communities of colour
  • 22.6% had at least one high risk condition, including: chronic lung disease, moderate to severe asthma, significant cardiac disease, severe obesity, diabetes, liver disease, and HIV infection
Time followed
  • At the time of the final primary efficacy analysis, participants had been followed for symptomatic COVID-19 disease for a median of 2 months after the second dose, corresponding to 3,304.9 person-years for the Moderna COVID-19 vaccine and 3,273 person-years in the placebo group.
Protection
  • Individuals may not be optimally protected until after receiving the second dose of the vaccine.
Efficacy
  • In participants 65 years of age and older, efficacy was 86.4%, compared to 94.1% overall among all trial participants 18 years or older
  • No difference in efficacy was observed between men and women or across different races or ethnicities.
Serious side effects
  • Overall, serious adverse events were reported in 1.0% of vaccine recipients and 1.0% of placebo recipients.
Non-serious side effects
  • Side effects observed during the clinical trials were typically mild, commonly reported side effects of vaccines and do not pose a risk to health. Overall, solicited side effects were more frequent in vaccine recipients compared to placebo, more frequent after the second dose compared to the first, and more frequent in adults 18 to 64 years of age than in those 65 years of age and above.
  • Most commonly reported side effects:
    • Pain at injection site: 88.4% (vs.17.0% in placebo)*
    • Fatigue: 68.5% (vs. 36.1% in placebo)
    • Headache: 63.0% (vs. 36.5% in placebo)
    • Myalgia: 59.6% (vs. 20.1% in placebo)
    • Arthralgia: 44.8% (vs.17.2% in placebo)
    • Chills: 43.4% (vs. 9.5% in placebo)
    • Fever: 14.8% (vs. 0.6% in placebo)
    • Swollen lymph nodes: 14.0% (vs 3.9% in placebo)*

Contraindications and precautions

The Moderna COVID-19 vaccine is contraindicated for:
  • Individuals with a history of anaphylaxis after previous administration of the vaccine.
  • Individuals with proven immediate or anaphylactic hypersensitivity to any component of the vaccine or its container, including polyethylene glycol.
  • Individuals who have received another vaccine (not a Moderna COVID-19 vaccine) in the past 14 days.
  • Individuals outside of the authorized age group (< 18).
  • Symptomatic individuals with confirmed or suspected SARS-CoV-2 infection, or those with symptoms of COVID-19. To minimize the risk of COVID-19 transmission, symptomatic individuals who arrive at an immunization clinic should be instructed to follow current local public health measures and be encouraged to get tested.
Precautions should be taken with:
  • Patients who have a bleeding problem, bruise easily or use a blood-thinning medication.
  • Patients with a history of fainting. Procedures should be in place to prevent injury from fainting and manage syncopal reactions.
  • Individuals who have experienced a serious allergic reaction, including anaphylaxis, to another vaccine, drug or food, should talk to their health professional before receiving the vaccine.
  • Patients who are pregnant or breastfeeding. See Pregnant and breastfeeding women.
  • Patients who are immunocompromised, due to disease or treatment. See Immunocompromised populations.
  • Patients with suspected hypersensitivity or non-anaphylactic allergy to COVID-19 vaccine components. Consultation with an allergist is advised prior to vaccination.

Vaccine ingredients

Nucleic acid
  • mRNA

This is the active ingredient of the vaccine. It contains the instructions your body needs to build antibodies to help protect you against COVID-19.

Lipids
  • Lipid SM-102
  • PEG2000 DMG (1,2-dimyristoyl-rac-glycerol,methoxy-polyethyleneglycol)*
  • 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)
  • Cholesterol

These ingredients are lipids, a type of fat that forms a protective shell around the active ingredient, mRNA, and allows it to “slide” into cells so it can work.

Salts, Acids, and Acid Stabilizers
  • Sodium acetate (Salt)
  • Acetic acid (Acid)
  • Tromethamine (Acid stabilizer)
  • Tromethamine hydrochloride (Acid stabilizer)

These ingredients are used as stabilizers for the vaccine to help maintain its pH close to that of a person’s body.

Sugar
  • Sucrose

Sucrose is a type of sugar that is used as a stabilizer to help the vaccine particles keep their shape when they are frozen

Water
  • Water for injection

Water is used to mix the vaccine ingredients into a liquid that can be injected into the body

Pfizer-BioNTech mRNA vaccine

Jump to:

The Pfizer-BioNTech mRNA vaccine showed 95% efficacy in preventing SARS-CoV-2 infection and is used both for preventing the occurrence of COVID-19 infection and diminishing the severity of the infection. For information on preparation, administration, storage, stability and disposal, see Vaccine administration.

Clinical trial details

Enrollment
Participant demographics
  • 41% were between 56 and 85 years old
  • Were of diverse racial and ethnic backgrounds:
    • White (83%)
    • Black or African American (8.8%)
    • American Indian or Alaska native (0.6%)
    • Asian (4.4%)
    • Native Hawaiian or other Pacific Islander (0.2%)
    • Multiracial (2.3%)
  • Participants with pre-existing stable disease were included (disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrolment)
  • Participants with known stable infection were included, including those with HIV, hepatitis B, and hepatitis C virus
Time followed
  • At the time of the final primary efficacy analysis, participants had been followed for symptomatic COVID-19 disease for a median of 2 months, corresponding to 2,214 person-years for the PfizerBioNTech COVID-19 vaccine and 2,222 person-years in the placebo group.
Protection
  • Based on the results of the clinical trials, the best protection is not achieved until 7 days after the second dose, but it remains unknown how long the protection will last.
Efficacy
  • 95%, with no difference in efficacy observed between men and women or across different age groups, races or ethnicities.
Serious side effects
  • Overall, serious adverse events were reported in 0.6% of vaccine recipients and 0.5% of placebo recipients.
Non-serious side effects
  • Side effects observed during the clinical trials were typically mild, commonly reported side effects of vaccines and do not pose a risk to health. Overall, solicited side effects were more frequent in vaccine recipients compared to placebo, more frequent after the second dose compared to the first, and more frequent in adults 18 to 55 years of age than in those 56 years of age and above.
  • Very common side effects (may affect more than 1 in 10 people):
    • Pain at injection site: 84.1% (vs. 7.7-14.0% in placebo)*
    • Fatigue: 62.9% (vs. 16.8-33.4% in placebo)*
    • Headache: 55.1% (vs. 13.9-33.7% in placebo)*
    • Muscle pain: 38.3% (vs. 5.3-10.8% in placebo)
    • Chills: 31.9% (vs. 2.8-6.4% in placebo)*
    • Joint pain: 23.6% (vs. 3.7-6.1% in placebo)*
    • Fever: 14.2% (vs. 0.2-0.9% in placebo)*
  • Uncommon side effects (may affect up to 1 in 100 people):
    • Enlarged lymph nodes

Contraindications and precautions

The Pfizer-BioNTech COVID-19 vaccine is contraindicated for:
  • Individuals with a history of anaphylaxis after previous administration of the vaccine.
  • Persons with proven immediate or anaphylactic hypersensitivity to any component of the vaccine or its container, including polyethylene glycol.
  • Vaccination should be deferred in symptomatic individuals with confirmed or suspected SARS-CoV-2 infection, or those with symptoms of COVID-19. To minimize the risk of COVID-19 transmission, symptomatic individuals who arrive at an immunization clinic should be instructed to follow current local public health measures and be encouraged to get tested.
  • Acutely ill individuals, as a precautionary measure.
  • Individuals who have received another vaccine (not a COVID-19 vaccine) in the past 14 days.
  • Individuals outside the authorized age group (< 16).
Precautions should be taken with:
  • Patients who have a bleeding problem, bruise easily or use a blood-thinning medication.
  • Patients with a history of fainting. Procedures should be in place to prevent injury from fainting and manage syncopal reactions.
  • Individuals who have experienced a serious allergic reaction, including anaphylaxis, to another vaccine, drug or food, should talk to their health professional before receiving the vaccine.
  • Patients who are pregnant or breastfeeding. See Pregnant and breastfeeding women.
  • Patients who are immunocompromised, due to disease or treatment. See Immunocompromised populations.
  • Patients with suspected hypersensitivity or non-anaphylactic allergy to COVID-19 vaccine components. Consultation with an allergist is advised prior to vaccination.

Vaccine ingredients

Nucleic Acids
  • mRNA

This is the active ingredient of the vaccine. It contains the instructions your body needs to build antibodies to help protect you against COVID-19.

Lipids
  • ALC-0315 = ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
  • ALC-0159 = 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide*
  • 1,2-Distearoyl-sn-glycero-3-phosphocholine
  •  Cholesterol

These ingredients are lipids, a type of fat that forms a protective shell around the active ingredient, mRNA, and allows it to “slide” into cells so it can work.

Salts
  • Dibasic sodium phosphate dihydrate
  • Monobasic potassium phosphate
  • Potassium chloride
  • Sodium chloride

These ingredients are salts that are used as stabilizers for the vaccine to help maintain its pH close to that of a person’s body.

Sugar
  • Sucrose

Sucrose is a type of sugar that is used as a stabilizer to help the vaccine particles keep their shape when they are frozen.

Water
  • Water for injection

Water is used to mix the vaccine ingredients into a liquid that can be injected into the body.

Patient resources New

This is not an exhaustive list of COVID-19 patient-facing resources. These resources were selected as they meet key criteria identified by CEP’s partners, stakeholders and Information experts: authoritative sources, short formats, engaging design, multilingual translations, and focus on key messaging. To combat information overload, we are strictly curating this list to avoid redundancy. Additions, updates and substitutions will be made on a case-by-case basis according to alignment with selection criteria.

Comprehensive vaccine FAQs
  • COVID-19 Vaccine (City of Hamilton): FAQs on safety and effectiveness of the COVID-19 vaccine, and links to resources simplifying the science of vaccines. Does include some Hamilton-specific information.
  • COVID-19 Vaccine Fact Sheet (City of Toronto): Not limited to Toronto-specific information. Vaccine FAQs and info sheet on benefits, side effects, ingredients and allergies, as well as vaccinations while pregnant or breastfeeding, with health conditions, or with previous COVID-19 infection. See “COVID-19 Fact Sheet and Translations” section for short info sheet available in 32 languages including English, French, Spanish, Arabic, and Chinese.
Multilingual information
Resources for Black communities

 

Resources for Indigenous communities
Resources for people with intellectual and developmental disabilities (IDD)

Top resources

These supporting materials and resources are hosted by external organizations. The accuracy and accessibility of their links are not guaranteed. CEP will make every effort to keep these links up to date.

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