Babies under 6 months old account for half of RSV hospitalizations in Canada: research

Nearly half of children hospitalized due to RSV since 2017 were infants under six months old, according to new research on the impact of the virus on Canadian kids.

Pediatric hospitals typically see a surge in cases of respiratory syncytial virus, which causes respiratory tract infections such as bronchiolitis and pneumonia, starting in November and continuing throughout the winter.

Dr. Julie Bettinger, professor of pediatric infectious diseases at UBC and scientist at BC Children’s Hospital Research Institute, says the study was done in order to better understand the impact in advance of a vaccine being approved.

"We wanted to start to get an idea of what the burden of disease looked like with this infectious disease who it most affected, who is at highest risk," she said.

Between 2017 and 2022, 49.8 per cent of hospitalizations were among babies younger than six months old. These babies also accounted for about 60 per cent of admissions to intensive care, Bettinger says. The average amount of time a child was hospitalized was four days, she adds.

"They're the most likely to get infected with it, and the most likely to have severe disease because of it," she explained.

"They are much more susceptible to a lot of infectious diseases and they just don't necessarily have the ability to fight them as well as an older child would. And this is often why you do see them ending up in the ICU."

The research also looked at the impact of COVID-19 on pediatric RSV hospitalizations and found the number plummeted dramatically during the 2020-2021 season.

"When everything was really shut down and we had a lot of social distancing and other preventative measures in place, RSV almost disappeared," Bettinger said.

The drop during the height of COVID-19-related restrictions suggests that preventative measures can be effective at lowering the number of cases among vulnerable kids while work continues on the immunization front.

"Eventually we will have some vaccines for that age group and we'll have more in our arsenal to be able to protect those infants. But right now, there's not a lot we can do," Bettinger said.

One of the things the study has highlighted is the potential promise of a vaccine for pregnant women which could help protect babies during their first months of life by passing on maternal antibodies, Bettinger says.

Immunizing children against COVID-19 and influenza is one thing Bettinger says parents of infants can and should do in order to minimize risk of other infections during respiratory season. Staying home when sick is also a precaution people should take, she says.

Last year, the number of kids hospitalized rose to 3,170 which was a fairly significant jump when compared to the pre-pandemic average of 2,522. However, the increase in the number of cases requiring hospitalization was not accompanied by a shift in the severity or an increase in the proportion of infections among infants.

"I don't want parents to be panicked about it, but it is also something that can make some children very severely ill," Bettinger says.

The study looked at hospital and ICU admissions at 13 hospitals, which account for 90 per cent of the country's pediatric beds.

With files from CTV News Vancouver's Lauren Pullen