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QUESTION: I’ve heard that there’s been a summer surge in COVID-19 cases. Should I get a booster shot now or wait until the fall for the new updated COVID vaccine?

ANSWER: It’s true that there’s been a recent rise in COVID levels in Canada, according to data from waste water collection sites across the country as of the end of July.

Not so long ago, many medical experts assumed that COVID would eventually turn into a seasonal infection – similar to influenza.

The flu virus tends to spread more readily in the fall and winter months. That’s why influenza shots are given during those seasons. It was expected that public-health providers would be able to administer flu and COVID vaccines together, making it easier for people to stay up-to-date with their inoculations.

However, with COVID, “there is no evidence that we are approaching anything that resembles seasonality,” said Dawn Bowdish, a professor of medicine and a Canada Research Chair in Aging and Immunity at McMaster University in Hamilton.

“We have been seeing waves of COVID every three to six months and there is no reason to believe that this is going to stop anytime soon” she added.

Dr. Bowdish said that each new wave is partly fuelled by the emergence of viral mutations or variants that are better able to evade the defences of the immune system.

Diminishing immunity within the population is also a factor. The protection you gain from a vaccination or an actual infection tends to wane after three to six months. For those who got a COVID vaccine this past spring, their immunity may already be starting to wane. The vaccine they received was designed to target the XBB variant, which was the dominant form of the virus last year.

This fall, public health officials are planning to have an updated vaccine that will help guard against the current crop such as the JN and KP variants. But, so far, there have been no official announcements about when the new vaccines will be available to the Canadian public.

“It may be October, it may be November – we just don’t know.” said Fahad Razak, a Canada Research Chair in Healthcare Data and Analytics at the University of Toronto.

In the meantime, those at risk of serious complications may want to consider getting an extra dose of the current vaccine, he said. Although the vaccine is no longer a perfect match for the variants in circulation, it’s close enough to give a boost to the immune system.

“It would provide some additional protection until later this fall when the new vaccine is released,” explained Dr. Razak, who is also an internal medicine physician at St. Michael’s Hospital in Toronto.

Based on the recommendations of the National Advisory Committee on Immunization (NACI), which provides advice to the provincial and territorial ministries of health, you should wait at least three months between vaccine doses.

High risk individuals who could potentially benefit from a vaccine shot include adults over the age of 65, those with immune-compromising medical conditions, residents of long-term care homes or other congregate settings, as well as pregnant women.

Even those not considered at high risk may have good reasons to receive a dose.

“If you’re planning a big holiday and you don’t want to get sick while you’re travelling, then this is something you can do to protect yourself,” said Allison McGeer, an infectious disease physician at Sinai Health System in Toronto.

She noted there is currently a high level of COVID activity in parts of Europe and the United States. Consider the fact that U.S. President Joe Biden was recently laid low by a bout of COVID.

Those who live with vulnerable individuals also have a sound rationale to get a shot. “You don’t want to be responsible for taking COVID home,” explained Dr. McGeer.

According to the latest statistics from June 30, just 18 per cent of people in Canada rolled up their sleeves for the vaccine that targets the XBB variant.

Dr. Bowdish sees no downside to people getting an extra shot of the current vaccine so long as it as has been at least three months since their last dose.

“All the data suggests it helps prevent infections in vulnerable people,” said Dr. Bowdish. “There is no reason to wait when rates are high.”

Nonetheless, she has concerns that people must decide for themselves whether to get a shot. Neither public heath officials nor expert groups such as NACI have provided any advice or guidance yet.

To further complicate matters, there is a dearth of reliable information about the level of COVID activity in Canada. Routine testing has fallen by wayside. Statistics on the number of people in hospital with COVID are incomplete.

And, in Ontario, the provincial government as of August ended the innovative wastewater-monitoring program, which provided evidence about the amount of virus being spread in the community.

“People are supposed to make decisions about their own health based on their level of risk. But how do they do that if they don’t have any data? I think this is really frustrating for the public,” said Dr. Bowdish.

Paul Taylor is a former Patient Navigation Adviser at Sunnybrook Health Sciences Centre and former health editor of The Globe and Mail.

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