Monoclonal antibody prophylaxis
Beyfortus® is not a vaccine. With vaccines, your child creates their own antibodies for long-lasting protection; however, Beyfortus® is an injectable medication that antibodies are passively accepted. The treatment provides protection and immunity against RSV as soon as it is received and works best within the first 6 months.
What is respiratory syncytial virus?
Respiratory syncytial virus (RSV) is a highly contagious viral infection, common in the winter. RSV is the most common respiratory illness in children under 5 years of age and infects nearly all children by their second birthday, with the highest rate among young infants.
Who is Eligible for RSV prophylaxis with Beyfortus®?
Beyfortus® is currently funded for RSV prophylaxis in infants who are residents of Ontario, and meet any of the following criteria:
- Born in 2024 prior to the RSV season (The National Advisory Committee on Immunization specifically recommends that infants 8 months of age or less be immunized).
- Born during the 2024–25 RSV season.
- Children up to 24 months of age who remain vulnerable from severe RSV disease through their second RSV season, with high-risk criteria as set out by RSV Program clinical criteria.
Who should not receive Beyfortus®?
Beyfortus® should not be given to those with known hypersensitivity or a history of a severe allergic reaction (e.g. anaphylaxis) to any product ingredients, including nonmedicinal ingredients or materials in the product’s packaging. Caution should be exercised when administering Beyfortus® to individuals with bleeding disorders. 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®.
What are the common side effects of Beyfortus®?
- Some infants may be sore, red, or swollen where the needle was given.
- Some infants may develop a fever or a rash, feel achy or irritable, seem tired, or have the symptoms of a cold.
- Tylenol® / acetaminophen (or liquid ibuprofen if your infant is over 6 months of age), may be taken afterwards, as directed, to reduce discomfort or fever.
What else do I need to know?
During the 2023/2024 RSV season globally demonstrated similar effectiveness results: - 82% – 90% in preventing RSV-associated LRTI requiring hospitalization
- 75.9% – 90.1% in preventing RSV-associated Intensive Care Unit admissions
- 69% – 90% overall reduction in RSV-associated hospitalizations compared to the previous season.
Respiratory Syncytial Virus (RSV) Prevention Beyfortus® (Nirsevimab) Fact Sheet (printable)
