Infant Respiratory Syncytial Virus (RSV)

To: Health Care Professionals in Niagara
From: Clinical Services Division, Niagara Region Public Health
Reference: Infant Respiratory Syncytial Virus (RSV)
Date: September 30, 2026

Ontario’s 2026–2027 infant RSV prevention program launches October 1, 2026 and continues to offer two publicly funded options to help protect infants from severe RSV illness.

Beyfortus® will continue to be offered to eligible infants and high-risk children based on the positive outcomes observed through the provincial RSV prevention program. Abrysvo® offered during pregnancy is an alternative option for infant RSV protection.

Health care providers caring for pregnant patients should discuss both options to support informed decision-making and obtain informed consent.

Key Points:

• Beyfortus® is expected to provide protection for up to 6 months and may provide protection throughout an entire RSV season. Beyfortus® provides antibodies that help protect babies against severe RSV illness shortly after it is given.
• Abrysvo® requires about 2 weeks to generate antibodies during pregnancy to help protect the baby from RSV after birth. Protection is expected to wane over time and may not extend beyond the first 6 months of life.
• Abrysvo® is available between 28 and 36 weeks' gestation when the infant is expected to be born during the RSV season
  • Health Canada has authorized Abrysvo® for use in pregnant persons between 32 and 36 weeks' gestation
  • The National Advisory Committee on Immunization (NACI) recommends Abrysvo® may be administered between 28 and 36 weeks' gestation
  • Administration before 32 weeks' gestation is considered off-label and should be solely based on the clinical judgment of the health care provider
• There is currently no evidence on repeat vaccination with Abrysvo® in subsequent pregnancies. To provide RSV protection to infants born in subsequent pregnancies, health care providers should consider administration of Beyfortus® to the infant after birth.
• Administration of both (Abrysvo® to the pregnant woman AND Beyfortus® to the infant) is NOT recommended, except under specific circumstances
  • Birth fewer than 14 days after vaccination, preterm birth, or certain conditions that increase the risk of severe RSV disease
• New RSV Physician Billing Code
  • A dedicated fee code (G849) is available for administration of all publicly funded RSV immunization products delivered through primary care
• Except for the updates outlined above, the provincial infant RSV prevention program remains largely unchanged from the 2025-2026 season. Refer to the 2026-2027 Ministry fact sheet for complete eligibility and administration guidance.
• The RSV season typically concludes on March 31, and RSV immunizing agents for the infant program should not be administered after this date

Health Care Provider Action

• Discuss Beyfortus® and Abrysvo® with expectant patients early enough to support informed decision-making before delivery
• Explain that families generally choose one option:
  • Abrysvo® during pregnancy, or
  • Beyfortus® for the infant after birth
• Refer to Respiratory Syncytial Virus (RSV) prevention programs | ontario.ca (for health care professionals)
• Review Provincial Council for Maternal and Child Health (PCMCH) health care provider fact sheet. This Ontario-specific resource aligns with the Ministry and can support patient counselling.
  • For additional support integrating RSV prevention discussions into primary care, review RSV Protect: Primary Care Implementation Brief (2026) which includes a decision-making algorithm. Note: this resource is not Ontario-specific. Enflonsia® (clesrovimab) discussed in this resource is not part of Ontario’s publicly funded infant RSV prevention program for the 2026-2027 season.

Office Staff Action

• Use the seasonal respiratory products order form to order infant RSV products. Abrysvo® is the only RSV vaccine approved for pregnant individuals. Do not use Arexvy® (RSV vaccine for older high-risk adults) for pregnant individuals.
• Patient resources:
  • Respiratory Syncytial Virus | ontario.ca
  • Display PCMCH’s RSV QR Code Poster in exam rooms and waiting areas so patients can easily access the fact sheets
  • Protecting Your Baby From RSV: Shared Decision Making Tool. Note: this resource is not Ontario-specific

For More Information

• Call 905-688-8248 or 1-888-505-6074 ext. 7396
• Research in Action: RSV Immunization Shows Strong Protection for Infants | Public Health Ontario
• Refer to our website for information on reporting adverse events after immunization