New data shows RSV shots prevent ‘most dangerous’ respiratory infection for newborns

As Katrina Bellavance’s seven-week-old daughter kept coughing non-stop, the Calgary mother unzipped her newborn’s pajamas and saw the skin around her tiny ribs tugging inward with each laboured breath. 

“In that moment, we knew we had to get her to the hospital as soon as possible,” Bellavance recalled of that frightening night back in 2023.

Her daughter was diagnosed with respiratory syncytial virus, or RSV, and spent several days in hospital on oxygen before she recovered. The common but dangerous infection ravages infants’ fragile respiratory systems, leading to difficulty breathing, wheezing, lung inflammation, pneumonia and, in rare cases, death.

RSV might not be a household term for many families, yet it’s “the No. 1 cause of hospitalization, year in, year out, in children during their first year of life,” said Dr. Jesse Papenburg, a clinician-researcher with the Montreal Children’s Hospital.

But those parental horror stories could one day be a thing of the past. There are now multiple ways to prevent severe RSV in newborns, including powerful monoclonal antibody shots — and real-world data from less than two years of global use shows stunning results.

The question now, medical experts say, is whether Canada can increase access and uptake to shots that remain unavailable to many families across the country.

RSV has remained a stubborn threat far longer than many other respiratory diseases. 

“For decades after we developed effective vaccines against other childhood infections, RSV remained unconquered,” wrote Dr. Jake Scott, a clinical associate professor of infectious diseases at Stanford University School of Medicine, in a recent editorial highlighting his team's latest research on vaccine effectiveness.

“That just changed. The transformation happened so quickly that many haven’t grasped its magnitude.”

Scott’s recent review of more than 500 global studies, published in the New England Journal of Medicine, found antibody shots cut infant RSV hospitalizations by more than 80 per cent. (A vaccine given to mothers during pregnancy, though less effective, still offers fairly high protection to infants as well, studies showed.)

The findings represent “one of the largest single advances in respiratory virus prevention in decades,” Scott wrote. 

In Spain, Madrid’s pediatric intensive care units reported around 90 per cent fewer RSV admissions, while Chile's national program saw hospitalizations drop by about three-quarters. 

Here in Canada, Papenburg’s research from Quebec estimated that more than half of the usual RSV-associated hospitalizations and ICU admissions were prevented last season after the province launched a universal infant antibody shot program.

Frontline teams really saw a difference in patient volumes, he told CBC News. The shots helped relieve some of the “condensed and intense pressure” RSV typically puts on the fragile pediatric health-care system, which can lead to surgeries being postponed because there aren’t enough ICU beds available, Papenburg said.