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.
‘One of the largest single advances’
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.)
Data from multiple countries shows monoclonal antibody shots for respiratory syncytial virus (RSV) is keeping more babies out of hospital, but not all provinces are covering the shots, even in the second year of availability in Canada.
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.
Access, uptake varies across Canada
Last season marked the first time Canada rolled out the new slate of RSV shots, including vaccines for pregnant women and older adults, along with nirsevimab, the one-and-done antibody shot that protects infants through the whole RSV season. Made by AstraZeneca, the shot is distributed in Canada under the name Beyfortus by Sanofi.
But the approaches to rolling out these shots across the country varied initially, and remain scattershot more than a year later.
More areas are providing universal antibody shot programs this season, while British Columbia Alberta, New Brunswick, and Newfoundland and Labrador remain the holdouts, only offering covered shots to babies deemed higher-risk.
Ontario, meanwhile, remains the only province that funds both the antibody shot for all infants, plus the maternal vaccine. Data from the first year of its program showed close to seven in 10 newborns received nirsevimab at birth before being discharged from health-care facilities.
But uptake varied widely, ranging between 32 to 90 per cent between hospitals.
Health Canada has approved the first respiratory syncytial virus (RSV) vaccine for pregnancy to protect infants from birth to six months of age. Pfizer Canada’s bivalent vaccine, Abrysvo, is the second approved for seniors over 60.
In Quebec, data showed roughly eight in 10 newborns received nirsevimab during the RSV season, with lower coverage among babies born before the season began.
“We have access to two products that are very, very effective at preventing young infants from getting the most dangerous respiratory infection that they can get,” said Dr. Jeffrey Pernica, an associate pediatrics professor at McMaster University in Hamilton.
But the logistics of actually rolling out these shots, he said, “is a more complicated thing than the science.”
The most reported reason for not giving the shot to infants was a parent or caregiver declining it, Ontario data showed. Pernica said birth timing is also a challenge: It’s hard to bring babies born in spring and summer back to the hospital to get an RSV shot in the fall.
“I am hopeful that as the years go by, we will get better and better uptake,” he said.
Several provinces still only offer shots to higher-risk infants
Other physicians say broader access is an even bigger concern, given the patchwork approach among provinces.
B.C. health officials told CBC News that there is “no plan to further expand” its RSV program this season, beyond those set aside for moderate- to high-risk infants. The shot can “still be obtained on a private pay basis,” though availability is at manufacturer discretion, the statement continued.
In Alberta, where there are also no plans to offer antibody shots beyond high-risk infants, health officials in the province told CBC News a “cost-effectiveness and feasibility analysis” is underway to inform decisions for next season.
Preventing infection across the population is crucial given how common RSV is in an infant’s first year of life, stressed pediatrician Dr. Cora Constantinescu, a clinical associate professor with the University of Calgary.
“I feel incredibly frustrated when I see a baby brought in with severe RSV to the hospital, to the ICU,” she said. “Some babies need ECMO [extracorporeal membrane oxygenation, a form of advanced life support] — which is essentially lung bypass — to survive.”
Equitable access is crucial, Constantinescu added, including more transparency on the costs of regional RSV immunization programs. (The list price for nirsevimab is close to $1,000 in Canada.)
Infant hospital stays for RSV can be upwards of $8,000: study
Other research suggests there may be a far higher cost associated with infant RSV infections compared to the price tag to prevent them.
A new study out of the University of British Columbia and BC Children’s Hospital Research Institute, published in November in The Lancet Regional Health – Americas, looked at nearly 30,000 hospitalizations across Canada between 2017 and 2023.
The research team found that babies under six months made up more than four in 10 RSV-related hospital admissions, and accounted for nearly half the estimated $66 million average annual cost of RSV hospitalizations. The average cost per hospital stay ranged widely, from $8,000 for a regular admission to more than $80,000 for infants on ventilation in the ICU.
While research is ongoing to explore the cost-effectiveness of these tools, it’s already clear that “preventing this infection is going to be a better approach in the long run,” noted study author Nirma Khatri Vadlamudi, who is now an assistant professor at the University of Florida.
(Katrina Bellavance)
Her study showed more than eight in 10 hospitalized children had no known risk factors — showing even healthy infants are vulnerable to this virus — while other research suggests children who are hospitalized with RSV early on also have a higher risk of developing asthma later in life.
“It’s not without long-term consequences,” Vadlamudi said.
Bellavance, the Calgary mother, says you can’t put a price on avoiding the terror of an RSV infection. She hopes more infants in her province will eventually have the option to get the shot her daughter didn’t have when she got sick back in 2023.
“I think it should be accessible,” she said. “The impact that even a four- or five-day hospital stay with an infant can have on a family is so significant.”
