Race between vaccines and variants is back on as B.1.617 takes hold in Canada

Some worry that this is the case, but with vaccine supplies in Canada intensify As second doses are accelerating across the country, others believe concerns about B.1.617 may be overblown.

So how vulnerable are we to B.1.617, the variant that was first identified in India also known as delta, and how worried are Canadians as we get close to reopening much of the country?

It depends on who you ask and the uncertainty that will happen in the next few weeks. But there is no doubt that we are in a much better place than we were when B.1.1.7, the variant first identified in the UK also known as alpha, Canada hit hard At the beginning of this year.

It’s kind of a concern for a reason. It’s clearly more transmissible,” said Dr. Isaac Bogosh, an infectious disease physician and member of the Ontario COVID-19 Vaccine Task Force.

“There are a lot of similarities in how this took over to be the dominant alternative, like we saw B.1.1.7 did several months ago. So you can’t ignore this, it’s something that warrants close attention.”

But Bogoch has not given up hope that the pace of vaccine rollout and the protection the shots provide can avert a potential catastrophe — even if research shows that a single dose of the Pfizer-BioNTech and AstraZeneca vaccines is only about 30% effective against it.

New data from Public Health England It’s also frustrating, as it has been found that two doses are more effective than one against B.1.617 and that it is not only more transmissible but also appears to cause more serious disease as well.

“All of this tells me that we really need to work on getting second doses faster, especially among vulnerable populations,” he said.

“But if this is a race between variants and a vaccine – the vaccine is going to win this round in Canada.”

Can ‘fall’ prioritize first doses with B.1.617

The UK’s reopening strategy is in jeopardy As it struggles with an increase in B.1.617 cases, mostly among unvaccinated individuals and those who have taken a single dose, it raises concerns that Canada’s decision to postpone second doses by up to four months could leave us even more vulnerable.

“This is the big risk with the single-dose strategy,” said Angela Rasmussen, a virologist with the Vaccines and Infectious Diseases Organization of Saskatoon.

“The real problem here is making sure that because it’s more transmissible, you have as many people who are as immune as possible and that’s where the delayed second dose strategy can fall short.”

Watch | A variant found in India linked to the resurgence of COVID-19 in the UK:

The resurgence of COVID-19 in the UK is linked to the B.1.617 strain that was first found in India and has raised concerns that it could delay plans to exit the lockdown. 1:56

Rasmussen criticized the delayed dose approach in the UK and Canada for the lack of concrete data to support it, but the move Provided partial protection for millions of Canadians And he helped us control the third wave at a time when vaccine supplies were low.

1.617 is more contagious—either because infected individuals can expel more infectious virus particles, or it takes fewer of these particles to infect others, or both—it is important that B.1.617 is more contagious, she said. Prioritizing second doses in vulnerable Canadians now.

“If you have a more transmissible variant, more people will get it,” she said. “Which means that more people will end up severely ill and more people will die from it.”

Canada lacks ‘clear vision’ on B.1.617

One advantage we had with B.1.1.7 that we didn’t have with B.1.617 was that it was easy to check because of luck – a simple genetic marker that appeared on test samples called S gene failure which indicated that the variable was most likely present.

But with B.1.617 we’re not so lucky, and experts say we could fly blind as cases may grow rapidly behind the scenes in Canada due to lack of surveillance.

“We don’t have the ability to see it like when we screen for B.1.1.7, because we don’t have that rapid screening test,” said Professor Ashley Tweet, an infectious disease epidemiologist and assistant. Professor at the Dalla Lana School of Public Health, University of Toronto.

Tuite says researchers have been forced to try to calculate the prevalence of B.1.617 with “incomplete data,” but there are early signs of “unknown“The variant is spreading in the background in Canada.

“All indications are that this is B.1.617, but we don’t have a very clear view of what’s going on,” she said. “The challenge at the moment is just to understand the scale of the problem and how geographically widespread it is at the moment.”

A recent cluster of COVID-19 was confirmed in Newfoundland and Labrador that grew to at least 60 cases of B.1.617, while outbreaks of the variant were also detected in British Columbia, Quebec, Alberta and Ontario.

Troy Day, a member of the Ontario Modeling Consensus Table and a mathematician at Queen’s University in Kingston, Ont. B.1.617 is likely to overtake B.1.1.7 to become the new dominant strain in Ontario by next month.

“The frequency of B.1.617 in Ontario is likely to be somewhere between 15 and 20 percent at this point,” he said. “Within the next month or month and a half, at the level of Ontario, the suggestion is that it’s probably in the 80 percent range.”

Day says that B.1.617 has a transmissible advantage over B.1.1.7, just like the latter over the original strain of the coronavirus, which could allow it to take over parts of the country in which it has already appeared, such as Ontario and Britain’s Columbia.

“The B.1.617 bomb isn’t detonating in any massive way at this point yet, but it’s not decreasing either,” he said. “So it appears that we do not yet have a sufficiently effective vaccine to keep this alternative under control.”

A ‘completely different situation’ with vaccines

Some experts say concerns about B.1.617 that threaten to jeopardize our reopening strategy or prompt another closure may be overstated, and that the current pace of vaccine rollout may be enough to control it.

“With vaccines, the situation is very different,” said Dr. Somon Chakrabarti, an infectious disease specialist at Trillium Health Partners in Mississauga.

“I’m not worried about this being a malfunction, my concern though is that the response to this will continue to push the can down the road in terms of reopening.”

New variants will continue to emerge in the future, Chakrabarti says, and we need to balance concerns about them with the context of Canada’s accelerated vaccine coverage of first and second doses.

“In a new post-pandemic world, we’re going to have outbreaks of these things and that doesn’t mean we necessarily need to stop reopening,” he said. “I’m just concerned that as more of this stuff comes out, this will continue to slow our plan.”

One thing Chakrabarti says has received less attention in the media and on social media is that while a single dose has been found to be only 30 percent effective against B.1.617, it is still very effective in preventing hospitalization and death.

There’s no denying that people who get fully vaccinated, Rasmussen says, are much more protected against the variant, but that the biggest threat from B.1.617 in Canada is to Canadians without a single dose.

“If the majority of people in Canada were vaccinated with two doses, we wouldn’t have a problem with the spread of variants,” she said. “Except likely, between unprotected pockets.”

As supply increases, Bogoch says, the threat of B.1.617 and other variants is likely to become less and less about vaccine accessibility and more about frequency and selection.

“People who ultimately choose not to be vaccinated will unfortunately be at high risk of contracting this infection,” he said. “Because this virus is not going anywhere.”

This is an excerpt from Second Opinion, a weekly report on health and medical sciences emailed to us Subscribers every Saturday morning. If you have not yet subscribed, you can do so by clicking Here.