Dr. Noah Ivers remembers thinking his infant son just had a cold.

But then, he was SA国际影视传媒渃learly struggling to breatheSA国际影视传媒� and had to be rushed to the hospital.

His son had respiratory syncytial virus, or RSV SA国际影视传媒� a common illness with often mild symptoms in children and adults. But for infants and seniors, RSV is a major cause of serious lower respiratory tract infections that can land them in hospital.

Despite his medical knowledge, Ivers said seeing his baby with an oxygen mask left him feeling SA国际影视传媒渦nempowered.SA国际影视传媒�

SA国际影视传媒淭he most you could do in that moment was hug them and hope,SA国际影视传媒� said Ivers, who is both a primary care physician and a scientist at WomenSA国际影视传媒檚 College Hospital in Toronto.

That happened about nine years ago, he said, noting thereSA国际影视传媒檚 no antiviral treatment for RSV SA国际影视传媒� so shielding infants from serious illness in the first place is key.

But until this year, babies across Canada were only given an antibody drug that protects against severe RSV if they were born prematurely or had other significant risk factors. For years, that antibody was palivizumab, which had to be given every month throughout the RSV season to maintain immunity.

This fall and winter, Ontario, Quebec and Nunavut will offer the newer monoclonal antibody nirsevimab SA国际影视传媒� approved by Health Canada in the spring of 2023 SA国际影视传媒� to all babies going through their first RSV season.

Unlike palivizumab, only one dose of nirsevimab is needed to provide protection throughout the fall and winter, when RSV is most widely circulating.

Although they are administered by injection, nirsevimab and palivizumab are not vaccines, which provoke the bodySA国际影视传媒檚 immune system to develop antibodies and other defences against a certain virus or bacteria.

Instead, they are already formed antibodies that give passive immunity against serious illness from RSV.

Last May, the National Advisory Committee on Immunization changed its guidelines to recommend SA国际影视传媒渂uilding towards a universal RSV immunization program for all infantsSA国际影视传媒� in Canada using nirsevimab, given the SA国际影视传媒渟ignificant burden of disease in all infants from RSV and the impacts of RSV on the Canadian health system.SA国际影视传媒�

Ontario, Quebec and Nunavut are the first provinces and territory to adopt that recommendation and offer nirsevimab to all infants free of charge SA国际影视传媒� a move Ivers welcomes SA国际影视传媒渁s a family doc and also as a parent whoSA国际影视传媒檚 been through this.SA国际影视传媒�

SA国际影视传媒淚f thereSA国际影视传媒檚 something you could do to prevent your kid becoming short of breath and watching them with their ribs heaving in and out and youSA国际影视传媒檙e watching them needing to get an oxygen mask SA国际影视传媒� if thereSA国际影视传媒檚 something simple in your power to do that, please, you know, take advantage of it,SA国际影视传媒� he said.

The other provinces and territories have not announced a universal RSV antibody program for this year. According to their websites, many of them are continuing to offer palivizumab, and only to premature and other high-risk infants.

In an email to The Canadian Press, the Saskatchewan ministry of health said it is SA国际影视传媒渃urrently assessingSA国际影视传媒� how to best use nirsevimab going forward.

In Ontario, SA国际影视传媒渁ll infants up to 12 months old, and children up to 24 months who are at high risk of severe illness from RSV are eligible for immunization,SA国际影视传媒� the provincial ministry of health website says.

Ivers said starting this month, hospitals in Ontario will offer nirsevimab to newborn babies. Doctors can also give infants the injection along with their routine vaccinations at the two and four-month marks, he said.

In Quebec, all infants born on or after April 2 of this year will be eligible for nirsevimab, according to the provincial website. ItSA国际影视传媒檚 not clear exactly when the injections will become available in that province.

Older babies with conditions that put them at higher risk of severe illness from RSV SA国际影视传媒� including cystic fibrosis, lung and heart conditions SA国际影视传媒� may also get nirsevimab during their second RSV season in Quebec.

Nunavut will also provide the antibody injection to newborns and infants during their first RSV season, as well as children up to 24 months old who continue to be at risk of severe illness. The territory has not yet confirmed specifically when it will be available.

Although infants born prematurely are at higher risk of getting very sick with RSV, itSA国际影视传媒檚 full-term infants who have made up the majority of hospitalizations each season, Ivers said.

SA国际影视传媒淭hey were healthy and unlucky,SA国际影视传媒� he said.

Ivers, who declared no affiliation or financial connection to the manufacturers of the monoclonal antibodies, said the preventive RSV treatment will also help the health-care system overall this respiratory virus season.

SA国际影视传媒淚f we have thousands less babies in the hospital, thereSA国际影视传媒檚 room suddenly in our system to do so much more,SA国际影视传媒� he said.

SA国际影视传媒淭hereSA国际影视传媒檚 knock-on effects that is beyond just the individual babies and their families that weSA国际影视传媒檙e protecting.SA国际影视传媒�

SA国际影视传媒擝y Nicole Ireland, The Canadian Press