What you need to know about RSV this flu season

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Three new shots for respiratory syncytial virus have been approved or are on the horizon for Canada, which could mean a sea change in the toll RSV takes on the very young and very old – if the shots were widely and freely available in this country.

But it appears that won’t be the case for the coming viral respiratory season.

Respiratory syncytial virus, or RSV, burst into public consciousness last fall as one of the three viruses behind a “tripledemic” that overwhelmed hospitals, particularly in the pediatric sector. Unlike for influenza and COVID-19, there was until recently no vaccine to counter RSV.

Now there are three new interventions designed to take the sting out of RSV: a once-a-season monoclonal antibody that provides passive immunity to babies, which Health Canada approved in April; a vaccine for people 60 and older, which Health Canada authorized last month; and a vaccine for pregnant women, which Canadian regulators are still reviewing but which the United States Food and Drug Administration greenlit on Aug. 21.

The purpose of vaccinating women against RSV late in pregnancy is to provide antibodies to their newborns, who risk developing complications such as pneumonia and bronchiolitis if they contract RSV.

Last year, “was a really, really heavy RSV season,” said Jesse Papenburg, a pediatric infectious disease specialist at Montreal Children’s Hospital. “But the truth is, year in and year out, we deal with an influx of patients due to RSV in the winter months.”

That means deploying shots to blunt the impact of RSV would be, in Dr. Papenburg’s words, “huge.”

The reasons for limited availability of new RSV shots in Canada vary by product, but come down partly to the slower-than-the-U.S. pace at which some important actors in Canada’s health care system make decisions about new vaccines.

Take Arexvy, the first Health Canada-approved vaccine for people 60 and older, the other demographic group hit hard by RSV. The Canadian regulator authorized the shot on Aug. 4.

With the notable exception of Ontario, no province or territory has committed to publicly funding Arexvy this season. Ontario announced on Thursday that it would cover the shot for seniors living in long-term care and some high-risk retirement homes.

Every other jurisdiction that responded to The Globe and Mail’s inquiries said, through spokespeople, that they were waiting for official guidance on the RSV vaccine for seniors from the National Advisory Committee on Immunization (NACI), the expert panel that makes vaccine recommendations.

NACI, however, doesn’t plan to issue recommendations for RSV vaccines for older adults this year, according to Anna Maddison, a spokeswoman for Health Canada and the Public Health Agency of Canada (PHAC).

She said by e-mail that NACI is instead prioritizing recommendations for new products to protect infants from RSV, including the highly anticipated maternal vaccine. But even those recommendations won’t be ready until the first half of 2024, too late for this respiratory virus season.

“Taking the necessary time to do a robust comparative analysis will allow Canadian jurisdictions to consider multiple different product options, and also to evaluate the cost-effectiveness of those options, which will be critical for decision making,” Ms. Maddison wrote.

Samir Sinha, the director of geriatrics at the Mount Sinai and University Health Network hospitals in Toronto, called it, “honestly disappointing,” that NACI won’t issue guidance on the RSV shot for seniors this year. Dr. Sinha is recommending it for all his patients, despite knowing cost could be a barrier in the absence of public coverage.

Arexvy-maker GSK said the vaccine for older adults will be available, beginning this month, at pharmacies across the country for a cost of $230. Some private insurers are expected to cover it as well.

Laura Tamblyn Watts, chief executive officer of CanAge, a national seniors’ advocacy organization, said NACI needs to be reformed and properly resourced so it can provide more timely guidance. Right now, the committee is made up of doctors, scientists and other experts who volunteer their time without pay on top of busy full-time jobs, Dr. Papenburg included. (He spoke on his own behalf, not NACI’s.)

“It’s incredibly frustrating for Canadians, particularly caregivers or vulnerable Canadians, to know that there is a vaccine,” Ms. Tamblyn Watts said of the RSV shot, “but we haven’t invested even in the process for review of those vaccines, let alone in getting them to people.”

When it comes to protecting babies from RSV, there is one option that has been available on a limited basis in Canada since the early 2000s: Palivizumab, a man-made protein that mimics RSV antibodies to protect infants from the virus.

Palivizumab is expensive and cumbersome to administer because it must be injected monthly during RSV reason. As a result, public coverage has been limited to high-risk babies, such as those born prematurely.

In April, Health Canada approved nirsevimab, a long-acting monoclonal antibody that is injected just once a season and which slashes the risk of hospital admissions and health care visits for RSV in infants by about 80 per cent.

Some Canadian jurisdictions were hoping to deploy nirsevimab for high-risk babies this season. But now, because it is unclear how many doses Sanofi, nirsevimab’s maker, will send to Canada or when those doses might arrive, several provinces, including British Columbia and Quebec, told The Globe they are sticking with palivizumab this season.

Others are leaving the door open to nirsevimab, just in case, as they roll out their usual palivizumab programs. Bethany Rubin, a spokeswoman for Sanofi Canada, said in a statement that nirsevimab is coming to Canada this season, but she declined to comment on supply.

Supply could be tight because of how widely nirsevimab is expected to be distributed south of the border, where the U.S. counterpart to NACI endorsed it for all babies under eight months of age, regardless of risk status, and for some high-risk toddlers entering their second RSV season.

The U.S. CDC’s Advisory Committee on Immunization Practices voted unanimously in favour of that recommendation on Aug. 3, less than a month after the U.S. FDA approved nirsevimab.

Anna Banerji, a professor of pediatrics, infectious disease and public health at the University of Toronto, has long advocated for palivizumab to be given to all babies in Nunavut and other Inuit communities, where RSV is a scourge that regularly sends infants to southern intensive-care units for treatment. “That’s a huge societal cost for the babies, the family and the community,” she said.

Dr. Banerji is hoping the lower cost of once-a-season nirsevimab will persuade the Nunavut government to make it available to all, not just high-risk babies such as those born prematurely. For now, Nunavut’s department of health is waiting to see what NACI has to say about protecting infants against RSV in the 2024-2025 season.