New RSV protections put prevention conversations on the clock for Canadian parents

With maternal vaccination and long-acting antibodies now available, experts say families need timely, locally tailored advice to protect babies from severe RSV.

Few moments are more alarming for parents than seeing a baby struggle for breath. What begins as a seemingly ordinary illness can quickly turn into feeding difficulties, exhaustion and, in some cases, a hospital admission. Respiratory syncytial virus, or RSV, remains one of the most common seasonal respiratory infections in infants, and it can lead to bronchiolitis, pneumonia and serious breathing problems. Canadian health figures cited by Dr Vivien Brown point to thousands of paediatric hospitalisations each year and millions of dollars in associated costs, underscoring that the strain falls not only on families but on the wider health-care system as well.

What makes RSV especially difficult to manage is that severe illness can be hard to predict. As Brown notes in the Good Men Project, many healthy, full-term infants under six months of age account for a large share of the most serious cases. That means parents cannot assume a baby is safe simply because there are no obvious risk factors. The Canadian Lung Association says the virus typically circulates from autumn into early spring in Canada, and while many people recover with mild symptoms, infants and young children remain vulnerable to lower respiratory tract infections that can require hospital treatment.

For years, prevention options were limited, but that picture has changed. The US Centres for Disease Control and Prevention says two main strategies are now used to protect infants: vaccination during pregnancy, which passes antibodies to the newborn, and long-acting monoclonal antibodies given directly to the baby after birth. In Canada, the Public Health Agency has also updated its guidance to include RSV-preventive products such as nirsevimab, clesrovimab, palivizumab and the RSVpreF vaccine, reflecting a broader toolkit than was available even a few seasons ago.

That expansion matters because severe RSV is not confined to a narrowly defined high-risk group. Brown cites recent Canadian research from seven paediatric hospitals in Ontario and Quebec during the 2024-25 season, which found that only a small minority of infants who tested positive had a comorbidity. The point is reinforced by the Public Health Agency’s guidance and the Canadian Immunisation Guide, which both stress that prevention is relevant for a wide range of infants, including some premature babies and children with certain medical conditions. In practical terms, the message is that many families deserve a conversation about protection before illness strikes.

Timing is critical. The CDC says maternal RSV vaccination is typically offered during a specific window late in pregnancy, while Canadian guidance also stresses that protection plans should be considered early enough for families to make informed choices. Brown argues that conversations should begin well before discharge from hospital after birth, not at the point when parents are already dealing with a newborn at home. That advice is particularly important because access is not uniform. Across Canada, funding, eligibility, prescribing authority and administration pathways can vary by province and territory, making local guidance just as important as the clinical evidence itself.

There is also a policy dimension. A cost-utility analysis in PLOS One suggests that different seasonal RSV prevention strategies may have different value depending on the perspective taken, whether that is the health system or society more broadly. That kind of analysis matters because governments and public health agencies are not simply deciding whether prevention works; they are deciding how to organise it, pay for it and make it reachable. Brown’s broader warning is straightforward: a recommendation is only useful if families can act on it. For RSV, that means clear advice, up-to-date local pathways and routine discussions in prenatal and infant care, so protection is not lost to delay, confusion or outdated information.