MONTREAL — The provincial agency in charge of health care in Quebec says the number of infants hospitalized from respiratory syncytial virus (RSV) has fallen sharply following a successful vaccination campaign.
The agency's director of public health operations says nearly 75 per cent of all eligible infants received more than 56,000 doses of the vaccine during the campaign. That's more than double the agency's initial target.
“Everyone, all health-care professionals across Quebec, worked and came together to raise awareness directly with parents,” Martine Leblanc-Constant said. “It was truly a collaborative effort by all the professionals involved.”
The preliminary results of a study out of Quebec’s public health institute show the vaccine, Nirsevimab, was more than 80 per cent effective at preventing emergency room visits and hospitalizations.
Dr. Jesse Papenburg, a pediatrician based at the Montreal Children’s Hospital and one of the study's co-authors, said they estimate more than 1,000 hospitalizations and more than 100 ICU admissions were averted as a result. The study is now under peer review.
“That translated into important public health gains, and also alleviated pressure on the pediatric health-care system,” he said.
In older children RSV usually just manifests as the common cold, Papenburg said. But that’s not the case for infants, who have no immunity to the virus. For infants and younger children, it is a common cause of bronchiolitis and pneumonia.
“It’s estimated that somewhere between 1 and 2 per cent of all children in Canada get hospitalized due to RSV in their first year of life,” said Papenburg, also an infectious disease specialist.
This was the province’s first ever RSV vaccination campaign aimed at parents, and Santé Québec said it “exceeded expectations.” It ran between last November and the end of March.
Infants born during the campaign, and those less than six months old from the onset of the RSV season then, were all eligible, Papenburg said. Older infants could also receive it if they were born prematurely or deemed at a higher risk of complications from the virus.
The provincial government is planning to relaunch the same vaccination campaign by Sept. 30.
Leblanc-Constant said they’re ahead for this upcoming season, unlike last fall, when shots of the vaccine were only available by early November.
“With the start of the school year and children returning to school and daycare, it's a good time to start planning for the immunization of our youngest ones, especially our babies, because it’s often older siblings who bring the virus home,” she said.
This report by The Canadian Press was first published Aug. 21, 2025.
Miriam Lafontaine, The Canadian Press
