Most RSV infections are in babies less than 1 year old. But protection remains out of reach for many

Most positive tests for RSV so far this season in Canada have been among the youngest, according to federal data. While Health Canada has approved an immunization that can protect all babies from the illness, it’s only available in a few jurisdictions.

For the week ending Nov. 30, about 51 per cent of RSV cases were in children one year of age and under, among those with age information. RSV typically causes a minor cold, but it can lead to severe illness in vulnerable groups. Older adults and newborns are among those most at risk, making it a leading cause of seasonal hospitalizations each winter for children in Canada. Approximately 10 per cent of all hospitalizations due to RSV require pediatric intensive care, highlighting the seriousness of the virus.

Nirsevimab, marketed by AstraZeneca and distributed in Canada by Sanofi under the name Beyfortus, is a single injection that offers protection to infants during the fall and winter when RSV is most prevalent. The medication includes lab-made monoclonal antibodies that can help prevent severe RSV infections. However, only Ontario, Quebec, and the territories have negotiated contracts to offer it for free to all infants. This leaves parents in other provinces, like Nova Scotia, feeling anxious and wanting to protect their children.

Researchers from the U.S. Centers for Disease Control and Prevention recently found that nirsevimab was effective in reducing RSV-related hospitalizations in children under five years old. Monoclonal antibody injections like nirsevimab provide direct antibodies to individuals, offering a shortcut to protection. Provinces currently offer palivizumab for high-risk infants, but many lower-risk babies do not have access to either protection.

The National Advisory Committee on Immunization (NACI) has not recommended nirsevimab for all infants in Canada due to its current price. Instead, it suggests prioritizing higher-risk infants like premature babies and eventually working towards a universal RSV immunization program for all infants. Canadian pediatricians are hopeful that nirsevimab can help prevent RSV infections in babies, as it has been shown to reduce the risk of hospitalization due to RSV by approximately 80 per cent.

Sanofi, the distributor in Canada, is committed to supporting broad immunization and working with provinces and territories to facilitate access to Beyfortus for all Canadian babies. Dr. Jesse Papenburg, a pediatric infectious disease specialist, expects that the immunization will be widely available nationwide within the next year or two, addressing the current disparities in access across provinces.

Encouraging uptake of nirsevimab is crucial to protecting infants from RSV. Families informed about the product prior to delivery have shown the best uptake rates. With thousands of doses already administered in Quebec and Ontario, efforts are being made to ensure that all infants have access to this important immunization.

As parents, like Hannah Markham in Nova Scotia, take precautions to protect their children from RSV, the availability of nirsevimab across Canada remains a key concern. With ongoing efforts to make the vaccine more widely accessible, the hope is to reduce the impact of RSV on infants and prevent severe illness during the winter months.