Health Canada approves RSV vaccine for maternal immunization

The new vaccine, Abrysvo, developed by Pfizer Canada to shield two of the most severely impacted groups from the respiratory syncytial virus (RSV)—newborns and people over 60—has received Health Canada's approval. It is Canada's first RSV vaccine designed for use during pregnancy to safeguard newborns until they are six months old, and also for individuals aged 60 and above. The U.S. Food and Drug Administration approved the vaccine for the same categories in 2023. RSV is an extremely contagious respiratory virus that resembles cold symptoms, but can carry risks of severe illness, such as pneumonia, necessitating hospitalisation for at-risk groups. For newborns, the Pfizer vaccine promises indirect protection via maternal immunisation in the third trimester, while for older adults, exposure to the virus can be avoided with a single shot. A different RSV vaccine for older adults was granted Health Canada approval last August, and an antibody medicine, nirsevimab to provide RSV resistance to newborns and infants, was approved in spring 2023. Health Canada will now collaborate with provincial and territorial partners to evaluate the demand, potential interest, and timeframes for these products' inclusion in existing RSV vaccination programmes. Their introduction is expected during the winter of 2024-25. While these developments are welcomed, their availability and accessibility across Canada are affected by supply constraints, as demonstrated by nirsevimab in 2023, due to high demand in the U.S. Consequently, the cost of implementing universal vaccination programmes has been stressed, along with the importance of cost-effectiveness analysis. Amid escalating cases of RSV, influenza, COVID-19 and other viruses, the infusion of new resources to counter RSV has been dubbed crucial. Pfizer Canada is currently evaluating the supply of its RSV vaccine, and collaborating with various stakeholders regarding the cost and the strategy to bring it to Canadians as swiftly as possible.