Here’s what to know about flu, COVID-19 and RSV this respiratory virus season

Respiratory virus experts advise Canadians to get their flu shot as soon as it becomes available in their area this fall. The flu vaccine is free for most provinces and will be offered to the general public by the end of October. The Centers for Disease Control and Prevention (CDC) recommends the flu vaccine for everyone six months of age and older.

A higher-dose version of the flu shot is advised for adults aged 65 and older due to their aging immune systems. A nasal spray alternative, FluMist, is also available in Canada but its availability may vary by region.

While last year's flu vaccine was not a perfect match with the circulating strains, it still provided 40% protection against requiring medical attention or hospitalization for flu infections. Immunologist Dr. Dawn Bowdish notes that the flu vaccine offers protection for about six months, with peak protection lasting approximately three months. Dr. Bowdish suggests that Canadians should get their flu shot as soon as possible, as the season may start earlier than usual.

Pregnant individuals, as well as those with asthma or other health conditions, should receive the flu vaccine, as it can be particularly severe for children. Early data shows that the H1N1 influenza A type is circulating in some parts of the country. Last year, the H3N2 strain was the dominant influenza A type in Canada. However, it is too early to determine if H1N1 will be the primary strain this season, as the Southern Hemisphere had an H3N2-dominated flu season this year.

Respiratory syncytial virus (RSV) is another respiratory virus that affects almost all children by the age of two. NACI recommends RSV antibodies, such as nirsevimab or clesrovimab, for all infants during their first RSV season and for high-risk infants during their second season. Individuals aged 75 and older and those with specific high-risk conditions, such as cardiorespiratory disease, immunocompromised status, or Down syndrome, should also be vaccinated against RSV.

COVID-19 remains a significant concern, with NACI recommending vaccination for individuals 65 years of age and older, residents of long-term care facilities, and those with compromised immune systems. Age is the most significant risk factor for severe illness from COVID-19, with seniors accounting for the majority of hospitalizations and deaths. The upcoming vaccine targets the XFG strain of the coronavirus, an Omicron subtype, and is expected to be similar to other Omicron subvariants in terms of illness severity.