This resource was created with information from and in collaboration with the Chief Medical Officer of Health to support primary care through Ontario’s new RSV Prevention Program for infants in the 2025/2026 RSV season.
2025-2026 RSV Prevention Program for infants in Ontario
Last Updated: August 26, 2025
Respiratory Syncytial Virus (RSV) is a major cause of illness among infants and young children. Ontario’s RSV program aims to provide protection from RSV to infants and to reduce hospitalizations and impact on system capacity during RSV season.1 The RSV Prevention Program will begin when product supply is available in October. While there are variations each year, active RSV season is generally between November – March.1,2
RSV Prevention Program for infants in Ontario 2025-2026
Jump to:
What is Ontario’s RSV Prevention Program for 2025-2026?
Are both products (Beyfortus and Abrysvo) necessary for an infant? Which product is recommended by the Ministry of Health?
Which infants will receive Beyfortus (Nirsevimab) in primary care and which in the hospital?
Who is considered to be a high-risk infant?
Should premature infants receive Beyfortus (Nirsevimab)?
What is Ontario’s RSV Prevention Program for 2025-2026?2
In addition to supporting their patients with decision-making around RSV prevention, primary care will be involved in administering immunizations to infants born outside of RSV season (e.g. January – September 2025) and those born outside a hospital setting (Beyfortus) or to pregnant individuals between 32-36 weeks gestational age (Abrysvo). The RSV Prevention Program for Infants will begin in early October, pending product availability.
Ontario is offering two products to prevent RSV in infants:
- Beyfortus (Nirsevimab)
- A monoclonal antibody given to infants (just before first RSV season or second season for high-risk children)
- Abrysvo
- An immunization product given during pregnancy (32-36 weeks gestational age)
NACI recommends prioritizing the use of Beyfortus because of its long-lasting effectiveness and protection. Due to its passively transferred antibodies, Abrysvo’s protection may not extend past 6 months of age in infants.2
Are both products (Beyfortus and Abrysvo) necessary for an infant? Which product is recommended by the Ministry of Health?
No, it is typically only necessary to use one product to prevent RSV.2 Both the Ontario Ministry of Health and the National Advisory Committee on Immunization (NACI) recommend the use of Beyfortus (Nirsevimab) as it has the strongest evidence of providing immediate protection to infants from RSV. They recommend that infants receive Beyfortus prior to discharge from hospital after birth instead of administering Abrysvo (RSVpre-F vaccine) to pregnant patients. In some circumstances, (e.g., baby is born less than 2 weeks from Abrysvo vaccination or high-risk) infants may benefit from Beyfortus in addition to the Abrysvo vaccine administered in pregnancy.2,3
Which infants will receive Beyfortus (Nirsevimab) in primary care and which in the hospital?1
Product
Who
Administration Setting
Beyfortus (Nirsevimab)
Infants up to 8 months of age, born before RSV season (i.e., on or after April 1, 2025)
Primary care or public health
Beyfortus (Nirsevimab)
Infants up to age 2 at high risk from RSV during 2nd RSV season*
- Primary care
- Pediatric specialists
- Outpatient hospital clinics
Beyfortus (Nirsevimab)
Infants born in 2025/2026 during RSV season* (until the season is declared over)
Hospital, soon after birth prior to discharge
Abrysvo (RSVpre-F vaccine)
Pregnant individuals from 32 to 36 weeks gestational age
- Primary care Obstetricians
- Midwives
- Others providing care (per scope of practice)
Who is considered to be a high-risk infant?2
High-risk infants include those with:
- Chronic lung disease of prematurity, including bronchopulmonary dysplasia/chronic lung disease (those with ongoing respiratory support and supplemental oxygen therapy at 36 weeks’ postmenstrual age or discharged home, if earlier)
- Note: Children who were < 12 months of age and approved for coverage in the previous RSV season for chronic lung disease and bronchopulmonary dysplasia remain eligible.
- Hemodynamically significant congenital heart disease
- Severe immunodeficiency
- Down Syndrome / Trisomy 21
- Cystic fibrosis with recurrent pulmonary exacerbations requiring hospitalization, deteriorating pulmonary function and/or severe growth delay
- Neuromuscular disease impairing clearing of respiratory secretions
- Severe congenital airway anomalies impairing clearing of respiratory secretions
Should premature infants receive Beyfortus (Nirsevimab)?3
Beyfortus (Nirsevimab) is the recommended monoclonal antibody to prevent RSV in infants born prematurely and should be provided to infants born at less than 37 wGA entering their first RSV season. Those entering their second RSV season who were born at less than 37 wGA and do not have another medical condition should not be routinely offered Beyfortus.
Beyfortus (Nirsevimab) and its administration
Jump to:
How does Beyfortus (Nirsevimab) work?
Beyfortus is a passive immunizing agent, meaning antibodies are given to a person rather than created by their immune system.3,4 It is an injectable monoclonal antibody, given as an intramuscular injection, that provides immediate protection against RSV in infants. It provides protection for at least six months after immunization. Only one dose of Beyfortus is needed for the RSV season.2
How effective is Beyfortus (Nirsevimab)?
Beyfortus is highly effective, demonstrating a reduction in hospital admissions associated with RSV by 81-83% and an 80% reduction in medically attended RSV respiratory tract infection in healthy infants.3 Monoclonal antibodies provide protection immediately and through the first months of an infant’s life (if given at birth) when infants are most vulnerable to RSV. Beyfortus is effective through 6 months after administration and may offer protection throughout the entire RSV season.2 After introducing the infant RSV Prevention Program in Ontario for the 2024/2025 RSV season, data collected from the Chief Medical Officer of Health’s Office saw a significant decrease in RSV cases among infants compared to the previous year.1
Beyfortus has been seen to have a higher efficacy and more immediate effect than Abrysvo (RSVpre-F vaccine). Abrysvo administered in pregnancy resulted in 57% reduction in hospitalizations associated with RSV in infants and reduced medically attended RSV respiratory tract infections in infants by 51% in their first RSV season. Protection from Abrysvo takes some time to develop and it is recommended to allow at least two weeks between administration and birth for transplacental transfer of antibodies.3
What are the side effects of Beyfortus (Nirsevimab)?
No serious events have been seen in studies done on Beyfortus. Adverse events are uncommon following RSV monoclonal antibodies and in randomized controlled trials, adverse events were similar to those receiving a placebo.3 Receiving Beyfortus will not give an infant RSV, as it is an antibody and not the virus that is in the product.
The most commonly occurring adverse reactions among Beyfortus clinical trial subjects were6:
- Rash, generally of mild to moderate intensity within 14 days of administration (0.7% of subjects)
- Fever within 7 days of administration (0.5% of subjects)
- Injection site reactions within 7 days of administration (0.3% of subjects)
Data collected from Beyfortus administration in the United States and Europe during 2023/2024 RSV season continued to support that there are no increased signals of significant adverse reactions from Beyfortus.5
Clinicians should exercise clinical judgement while considering response to side effects such as fever. The Chief Medical Officer of Health suggests that primary care may employ a standard response like with fever after other immunizations. If there is fever after Beyfortus administration, it can be monitored for 24-48 hours if the infant is otherwise well (i.e. feeding, diapering, no apparent distress). Infants over 2 months may take Tylenol for their fever. High fever (over 40°C) should be managed emergently, even post-administration.1
When is Beyfortus (Nirsevimab) contraindicated?
Individuals with known hypersensitivity or a history of a severe allergy to any other humanized monoclonal antibodies or component of the product, including non-medicinal ingredients or materials in the product’s packaging, should not receive Beyfortus.3 Individuals who have a moderate or severe acute illness, with or without fever, do not need to wait until they have recovered before receiving Beyfortus.1
Should infants who have recovered from an RSV infection receive Beyfortus (Nirsevimab) this season?
Beyfortus is typically not required or advised for an infant who has already had a confirmed RSV infection during the current RSV season. The benefit of administering Beyfortus after the infant has recovered from RSV is uncertain and likely minimal, as the risk of rehospitalization within the same season is very low. However, it may be worth considering for infants with severe immunodeficiencies who may not develop a sufficient immune response to the RSV infection. There is no specific waiting period recommended between an RSV infection and the administration of Beyfortus.
RSV Prevention Program and primary care
Jump to:
What is the role of primary care in RSV prevention?
How do I check if an infant has received their Beyfortus (Nirsevimab) dose?
How to obtain Beyfortus (Nirsevimab) for your primary care practice
Storage and handling information
At what dose should Beyfortus (Nirsevimab) be given?
Can Beyfortus (Nirsevimab) be given with other immunizations? Can it be given at other scheduled appointments?
Is Beyfortus (Nirsevimab) covered by OHIP?
Can parents access Beyfortus (Nirsevimab) privately for children outside of the RSV Prevention Program eligibility?
Checklist
Patient resources
Talking to patients about RSV prevention
What is the role of primary care in RSV prevention?2
Primary care has a multifaceted role to play in Ontario’s RSV Prevention Program for infants. This includes:
- Equipping parents to make choices, including addressing any hesitancy concerns, about RSV prevention for their infants
- Administering Beyfortus to infants who did not receive their dose in hospital after birth or prior to discharge (e.g. infants born in 2025 outside of RSV season or outside the hospital during RSV season)
How do I check if an infant has received their Beyfortus (Nirsevimab) dose?5
If infants received their dose of Beyfortus in hospital, it will be recorded in the BORN Information System and on the patient’s discharge summary. It is recommended to confirm with parents that their infant received Beyfortus in hospital.
How to obtain Beyfortus (Nirsevimab) for your primary care practice
Primary care can order Beyfortus through their usual vaccine source (i.e., local public health unit or OGPMSS) in the same manner as any routine immunization product.2 Product will be obtained via cold chain delivery systems with orders picked up by the facility or delivered by a PHU approved courier. PHUs will release a one-month supply of product, similar to vaccine ordering. It is recommended that primary care review lists of infants born since January 2025 to determine an appropriate amount of Beyfortus that may be needed. Contact your local public health unit for further information regarding processes and ordering time as it may vary by PHU.1
Storage and handling information6
Beyfortus (Nirsevimab) comes as a single pre-filled syringe (50 mg or 100 mg). It should be stored in its original container to protect it from light and should be kept between 2° C and 8° C. Do not freeze.
At what dose should Beyfortus (Nirsevimab) be given?
The usual dose of Beyfortus varies by age and weight6:
Category and weight
Dose
Timing
Infants born during the 2025/26 RSV season
Less than 5kg
50 mg in 0.5 mL
(100 mg/mL) intramuscular injection
Administered from birth
Infants born during the 2025/26 RSV season
5kg or more
100 mg in 1 mL
(100 mg/mL) intramuscular injection
Administered from birth
Infants born outside of the 2025/26 RSV season (from April 1, 2025 i.e. less than 8 months)
Less than 5kg
50 mg in 0.5 mL
(100 mg/mL) intramuscular injection
Shortly before the start of the RSV season
Infants born outside of the 2025/26 RSV season (from April 1, 2025 i.e. less than 8 months)
5kg or more
100 mg in 1 mL
(100 mg/mL) intramuscular injection
Shortly before the start of the RSV season
Children at continued high-risk from RSV entering their second season
200 mg (two 1 mL intramuscular injections of 100 mg/mL)
Shortly before the start of their second RSV season
For high-risk children entering their second RSV season who weigh less than 10 kg, a single dose of 100 mg may be considered at clinical discretion.3 If a child is undergoing cardiac surgery, they may be given an additional dose of Beyfortus after the procedure, see product monograph for more details.6
Update Can Beyfortus (Nirsevimab) be given with other immunizations?3 Can it be given at other scheduled appointments?
Yes, Beyfortus can be given at the same time, before or after other routine childhood immunizations, including influenza. It is a passive immunizing agent specifically targeted against RSV whose monoclonal antibodies do not interfere with the immune response to other immunizations.
Beyfortus can be administered at visits you may already have scheduled with your patients. Here are some opportunities for infant visits in which you may choose to include Beyfortus administration, based on the infant’s month of birth.2
Birth month
Timeline to administer
July-August
2-month visit
May-June
4-month visit
March-April
6-month visit
Any time alternative
With flu immunizations
Is Beyfortus (Nirsevimab) covered by OHIP?2
Beyfortus can be billed using fee code G538, which provides renumeration for administering immunizations that are not explicitly listed. For more information about billing and RSV prevention, see OMA’s guidance.
Can parents access Beyfortus (Nirsevimab) privately for children outside of the RSV Prevention Program eligibility?1
No. Beyfortus will not be available for the private market in Canada.
Checklist2
For my patients with infants born in 2025 outside RSV season (typically November – March) or giving birth outside of the hospital during RSV season
Educate parents about Beyfortus and how it can reduce risks from RSV (could be during a well-baby visit or appointment with expectant parent). Ask if newborns received Beyfortus in the hospital
Provide patient education handout/links to help them consider their choice
Schedule appointment for administering Beyfortus (can be with other immunizations such as alongside flu clinics)
Order product from Public Health Unit for scheduled appointment
For my patients giving birth in hospital (during RSV season)
Educate parents about Beyfortus and how it can reduce risks from RSV
Provide patient education handout/links to help them consider their choice
Update To reach out to patients eligible for Beyfortus, click to download CEP’s sample letter to patients.
Use EMR searches from Amplify Care or OntarioMD to identify patients who may benefit from Beyfortus.
Patient resources
Information on RSV Prevention for infants and high-risk children
- Preventing RSV in infants: What you need to know (Immunize Canada)
- Protecting your child from RSV (Provincial Council for Maternal and Child Health)
- Fact sheet for parents and expectant parents in multiple languages (Provincial Council for Maternal and Child Health)
- Le virus respiratoire syncytial (VRS) (Information in French from Eastern Ontario Health Unit)
- Preventing RSV in newborns and infants video series (Eastern Ontario Health Unit)
- RSV Fact Sheet for Indigenous Parents and Caregivers in Ontario (Information in 4 Indigenous languages from the Indigenous Primary Health Care Council and the Provincial Council for Maternal and Child Health)
Information on RSV in infants and children
- What you need to know about Respiratory Syncytial Virus (RSV) (Canadian Premature Babies Foundation)
- Respiratory syncytial virus (RSV): What you need to know (Immunize Canada)
Talking to patients about RSV prevention
Consider using the PrOTCT framework to help you approach conversations about RSV prevention with patients. It can help support collaborative decision making as you share information and build trust with parents in your practice.
Pr: Presume they will get the immunization with positive statements.
Talking tip:
- “I am taking steps towards RSV prevention with all the infants and/or high-risk children in my practice.“
O: Offer to share your knowledge about the facts and experience with the immunization.
Talking tip:
- “I have been educating myself on the science behind it. Can I share what I know with you?”
T: Tailor the recommendation to their specific health concerns.
Talking tip:
- “The prevention product will benefit your infant by:
- Providing them direct protection from infection and hospitalization during a time when they are most vulnerable to RSV (in the 2024/2025 season, Ontario saw a significant reduction in infants hospitalized with RSV after introducing the Infant RSV Prevention Program)
- Reducing the risk that you will need to take time away from work and other activities when they are sick.”
C: Address specific concerns (should not be the bulk of the conversation).
Talking tip:
- “Are there any particular concerns about RSV prevention you would like to discuss?”
T: Talk through a specific plan for where and when to get the vaccine.
Talking tip:
- “Let’s make a plan for when your child will receive the RSV prevention product“2:
- For my patients with infants born before RSV season or giving birth outside of the hospital: “We can book an appointment for your infant right here in our clinic. It can be given alongside the other routine prevention products for your child if the timing is appropriate.“
- For patients giving birth in hospital (during RSV season): “When you give birth in the hospital, they will offer an RSV prevention product for your infant. I can share some more information with you so you can feel confident protecting your infant from RSV.”
- For patients who are still hesitant: “Let’s schedule another appointment to talk more about your questions about protecting your child from RSV.“
For more support and information about approaching conversations with your patients about vaccine hesitancy, see the OMA’s Vaccine Hesitancy resource.
PrOTCT Framework modified with permission from the Centre for Effective Practice. (December 2021) Constantinescu, Ivers. N., Grindrod. K. PrOTCT Framework: Ontario. Toronto: Centre for Effective Practice.
References
-
[1]
Ontario Ministry of Health. Appendix B: Respiratory Syncytial Virus Prevention Program for All Infants, High-Risk Children and Pregnancy. 2024.
-
[2]
Expert opinion, Chief Medical Officer of Health.
-
[3]
Respiratory syncytial virus (RSV): Canadian Immunization Guide [Internet]. 2024 [cited 2024 Aug 2]. Available from: https://link.cep.health/rsv7
-
[4]
CDC. Immunity Types [Internet]. Vaccines & Immunizations. 2024 [cited 2024 Aug 22]. Available from: https://link.cep.health/rsv8
-
[5]
Ontario College of Family Physicians Community of Practice. Webinar: Infectious disease: Circulating seasonal illnesses & important vaccine updates [Internet]. 2024 Jul 26. Available from: https://link.cep.health/rsv9
-
[6]
Sanofi Pasteur Limited. Product monograph: Beyfortus [Internet]. 2024. Available from: https://link.cep.health/rsv10
Acknowledgement and legal New
The 2024-2025 RSV Prevention Program for infants in Ontario resource was developed using the Centre for Effective Practice’s (CEP’s) integrated knowledge translation approach as part of the Knowledge Translation in Primary Care (KTinPC) Initiative. This approach ensures that clinicians are engaged throughout the development processes through the application of user-centered design methodology. This resource was created with information from and in collaboration with the Chief Medical Officer of Health. End users and clinical experts were also engaged to provide feedback. Funded by the Ministry of Health, the KTinPC Initiative supports primary care clinicians with a series of clinical tools and health information resources. Learn more about the KTinPC Initiative.
This resource was developed for licensed health care professionals in Ontario as a guide only and does not constitute medical or other professional advice. Health care professionals are required to exercise their own clinical judgement in using this tool. Neither the CEP, Government of Ontario, nor any of their respective agents, appointees, directors, officers, employees, contractors, members or volunteers: (i) are providing medical, diagnostic or treatment services through this resource; (ii) to the extent permitted by applicable law, accept any responsibility for the use or misuse of this resource by any individual including, but not limited to, primary care providers or entity, including for any loss, damage or injury (including death) arising from or in connection with the use of this resource, in whole or in part; or (iii) give or make any representation, warranty or endorsement of any external sources referenced in this resource (whether specifically named or not) that are owned or operated by their parties, including any information or advice contained therein.
This resource is a product of the CEP. Permission to use, copy, and distribute this material is for all noncommercial and research purposes is granted, provided the above disclaimer, this paragraph and the following paragraphs, and appropriate citations appear in all copies, modifications, and distributions. Use of this resource for commercial purposes or any modifications of the resource are subject to charge and must be negotiated with the CEP (info@cep.health).
For statistical and bibliographic purposes, please notify the CEP (info@cep.health) of any use or reprinting of the resource. Please use the following citation when referencing the resource: Reprinted with Permission from Centre for Effective Practice. (September 2024). 2024-2025 RSV Prevention Program for infants in Ontario. Ontario. Toronto: Centre for Effective Practice.
Developed by
