COVID-19 vaccine third dose uptake still lagging in Ontario, science table head says

Shannon Bowler receives a COVID-19 vaccine at a mass vaccination clinic held inside Scotiabank Arena in Toronto on Sunday, June 27, 2021. THE CANADIAN PRESS/Cole Burston

There is still much work to be done to make sure that Ontarians get a third COVID-19 vaccine shot, the scientific director of Ontario's COVID-19 science advisory table says, as discussion starts to ramp up around fourth doses.

“Although a lot of the conversation right now is around the fourth dose, to me scientifically the clearest opportunity, the thing that we should be doing — and it's not an availability question, the vaccine is available to us — is that third dose,” Dr. Fahad Razak told CP24 Monday.

His comments come as opposition parties in Ontario call for fourth doses to be expanded in the province, as Quebec has now done, ahead of a potential fall wave.

Third doses are currently recommended in Ontario for all those aged 12 and up, while fourth doses are being offered to those 60 and over, as well as those 18 and up who are First Nation, Inuit or Métis.

But according to the latest vaccination data released by the province, just 57 per cent of those 12 and up have had a third dose, despite widespread availability in the province.

“That third dose, that is the dose that clearly gives you increased protection against not only infection, but against severe disease. And severe disease is the thing we care about the most,” Razak said. “So there is a large number of people in Ontario right now who are eligible for that third dose who haven't received it.”

Ontario began rolling out third doses in November and expanded eligibility to anyone 18 and up in late December. However uptake of the third dose was disappointing and Ontarians have been slow to get the shot.

While some people have indicated they don’t want to get more than the first two doses originally prescribed, Razak said that advice around how many shots are needed has changed as the pandemic has progressed and the virus has changed.

“The virus has proven to be a really terrible adversary for us,” Razak said. “And it has mutated to the extent that what is currently circulating now in Ontario, in Canada and the world is almost unrecognizable compared to what we originally saw and what we developed vaccines against.

“And so you have these increasing rounds of vaccination come out because we're doing the best we can to protect ourselves against a mutating virus.”

However he added that newer vaccines are showing promise in providing better protection against the latest strains of the virus.

“What happens in the future is really unclear. One of the things that's very promising is vaccines that are being tailored and developed against what's circulating now, as opposed to what was in place two years ago when the virus first emerged out of China,” Razak said. “And so there's a hope that these newer generations of vaccines especially will give us more durable protection.”

He said that in the meantime and especially heading into the fall when there will be other respiratory illnesses circulating, it makes sense to get any shots that you are eligible for and to continue to be thoughtful about masking in high-risk settings to avoid infection.