With the spread of B.1.617 in Canada, the competition between vaccines and variants restarted


This is an excerpt from Second Opinion, which is a weekly review of health and medical news, sent to Subscribers every Saturday morning.If you haven’t subscribed yet, you can click Here.


A new variant of the coronavirus is circulating in Canada, and experts are divided on whether it will expose our priority to the first dose of the COVID-19 vaccine and endanger the weakness of the reopening strategy for most parts of the country.

Some people worry that this is the case, but the vaccine supply in Canada accelerate And the second dose has accelerated nationwide, and others believe that concerns about B.1.617 may be exaggerated.

So how big is the risk we face from B.1.617, this variant was first discovered in India, also known as delta, how worried should Canadians be when we are close to reopening most of the country?

It depends on who you ask and the uncertainty in the next few weeks. But there is no doubt that we are in a much better situation than it was in B.1.1.7. B.1.1.7 is a variant first discovered in the UK, also known as alpha, Hitting Canada hard Earlier this year.

People walked in downtown Montreal on Thursday because the province will reopen in the next few days. Some experts said that B.1.617 may face the risk of future blockade or worse-this is the fourth wave of destruction. (Jean-Claude Taliana/CBC/Radio Canada)

“I take it very seriously. For some reason, it is a worrying variant. It is obviously more contagious,” Isaac Bo, an infectious disease doctor and member of the Ontario COVID-19 Vaccine Working Group. Said Dr. Isaac Bogoch.

“This has a lot of similarities in how it became the dominant variant, as we saw B.1.1.7 did a few months ago. So you can’t ignore this, it’s something that deserves close attention.”

But Bogoch has not lost hope. The speed of our vaccine launch and the protection provided by the vaccine can avoid potential disasters even though studies have shown that a dose of Pfizer-BioNTech and AstraZeneca vaccines is only about 30% effective Opposed.

New data from Public Health England It is also frustrating to find that two doses are more effective against B.1.617 than one dose, and that it is not only more transmissible, but also seems to cause more serious illness.

“All of this tells me that we need to really work hard to get the second dose of vaccine faster, especially among vulnerable people,” he said.

“But if this is a race between variants and vaccines-the vaccine will win this round in Canada.”

B.1.617 Prioritize the possibility of “failure” in the first dose

Britain’s reopening strategy is in danger With the increase in B.1.617 cases, mainly people who have not been vaccinated and those who have received one dose of vaccine, there is concern that Canada’s decision to postpone the second dose of vaccine for up to four months may make us more vulnerable.

Angela Rasmussen, a virologist at the Saskatoon Vaccines and Infectious Diseases Organization, said: “This is indeed a huge risk for a single-dose strategy.”

“The real issue here is to ensure that because it is more contagious, you have as many people as possible with as many immunity as possible. This is where the delaying the second dose strategy may fail.”

Watch | Variants found in India related to the comeback of COVID-19 in the UK:

The resurgence of COVID-19 in the UK is related to the B.1.617 strain first discovered in India, which has raised concerns that it may delay plans to lift the lockdown. 1:56

Due to the lack of specific data, Rasmussen has been criticizing the delayed dose method in the United Kingdom and Canada, but this has already Partial protection for millions of Canadians And it helped control our third wave of the epidemic when the vaccine supply was insufficient.

She said that because B.1.617 is more contagious—either because an infected individual can excrete more infectious virus particles, or because it requires fewer virus particles to infect others, or both— —The important thing is The second dose is now given priority to vulnerable Canadians.

“If you have a variant that is easier to spread, more people will get it,” she said. “This means that more people will eventually become seriously ill and more people will die as a result.”

The reopening of bars and restaurants in the UK has always been a cause for celebration, but the country is now battling an increase in B.1.617 cases, mainly by people who have not been vaccinated and those who have received a dose of the vaccine. (Associated Press)

Canada lacks a “clear understanding” of B.1.617

One of our advantages in B.1.1.7 is that we did not have in B.1.617 because it is easy to screen due to a lucky breakthrough-a simple genetic marker that appears on the test sample, called S gene failure This indicates that the variant may exist.

But for B.1.617, we are not so lucky. Experts say that we may fly blindly, because the lack of surveillance may lead to a rapid increase in the number of cases behind the scenes in Canada.

“We don’t have the ability to see it during screening for B.1.1.7 because we don’t have that kind of rapid screening test,” said Professor Ashleigh Tuite, an infectious disease epidemiologist and assistant, Professor of the Dalarana School of Public Health at the University of Toronto .

Tuite said that researchers were forced to try to use “incomplete data” to calculate the spread of B.1.617, but there are early signs that “unknown“Variants are spreading in the Canadian context.

“All signs indicate that this is B.1.617, but we don’t have a completely clear view of what is happening,” she said. “The challenge now is just to understand the severity of the problem and how extensive it is now geographically.”

recent COVID-19 cluster in Newfoundland and Labrador The situation that has grown to at least 60 cases is confirmed as Caused by B.1.617, And also discovered the outbreak of this variant British Columbia, Quebec, Alberta and Ontario.

A member of the Ontario Modeling Consensus Table and a mathematician Troy Day of Queen’s University in Kingston, Ontario, stated that B.1.617 may surpass B.1.1.7 next month and become the new dominant strain in Ontario.

“At this stage, the frequency of B.1.617 in Ontario may be between 15% and 20%,” he said. “In the next month or one and a half months, within Ontario, the recommendation may reach 80%.”

Day said that B.1.617 has the advantage of being transmissible over B.1.1.7, just like the latter relative to the original strain of the coronavirus, which may allow it to take over Colombia in parts of the country (such as Ontario and the United Kingdom) that have emerged.

“B.1.617 has not exploded in any huge way at this stage, but it hasn’t diminished,” he said. “So we don’t seem to have a sufficiently effective vaccine to control this mutation.”

The “very different situation” of the vaccine

Some experts said that concerns that the B.1.617 threat jeopardizes our reopening strategy or prompts another lockdown may be exaggerated, and the current vaccine launch speed may be sufficient to contain it.

“With vaccines, things are very different,” said Dr. Sumon Chakrabarti, an infectious disease expert at Trillium Health Partners in Mississauga.

“I am not worried that this will cause damage, but I am worried that in terms of reopening, the response to this will continue to be delayed.”

Some experts say that concerns that B.1.617 may jeopardize the reopening plan or prompt a re-blockade may be exaggerated, and the current vaccine launch speed may be sufficient to contain it. (Darryl Dyke/Canada Press)

Chakrabarti said that new variants will continue to emerge in the future, and we need to balance our concerns about them with our accelerated coverage of the first and second doses of vaccines in Canada.

“In the new world after the pandemic, we will explode these things, but that doesn’t mean we must stop reopening,” he said. “I’m just worried that as more of these things emerge, it will continue to slow down our plans.”

Chakrabarti said that one thing that has attracted less attention in the media and social media is that although a dose of B.1.617 is found to be only about 30% effective, they are still very effective in preventing hospitalization and death.

Rasmussen said that it is undeniable that people who are fully vaccinated have greater protection against this mutation, but the greater threat of B.1.617 in Canada is that Canadians have not even received a dose.

“If you vaccinate most people in Canada twice, we won’t have the problem of mutation transmission,” she said. “Unless it is possible, among the few people who have not been vaccinated.”

Bogoch said that as the supply increases, the threat of B.1.617 and other variants may be less and less related to the availability of vaccines, and more related to hesitation and choice.

“Sadly, people who ultimately choose not to be vaccinated have a high risk of contracting this virus,” he said. “Because this virus won’t go anywhere.”


This is an excerpt from Second Opinion, which is a weekly review of health and medical news, sent to Subscribers every Saturday morning.If you haven’t subscribed yet, you can click Here.



Source link