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.
Canada is preparing to battle more contagious variants of the coronavirus that threaten to jeopardize reopening plans across the country due to a massive increase in vaccine supplies, Canadians’ readiness to get vaccinated and some promising research on new vaccines.
Daily COVID-19 cases, hospitalizations and deaths occur significantly decreased across the country to levels not seen since the fall, while vaccine shipments are set to grow exponentially — with More than 5.3 million doses Arrive next week alone.
to date, More than 28 million doses of vaccine Managed all over Canada, circa 72 percent of eligible Canadians have at least one shot and are close to 12 percent He owns two.
However, there have been growing concerns about the spread of variables that have raised doubts about whether we can safely reopen society in the hardest-hit areas of Canada, particularly that The UK is grappling with the variant known as Delta, or B.1.617.
Despite the many uncertainties that lie ahead, experts say early data from the UK and a new study just released in British Columbia suggest the same way forward – getting as many guns as possible as quickly as possible.
Variable vs Vaccines
A recent study from Public Health England (PHE) I looked at how effective the first dose was against the delta variant.
The study found that the Pfizer-BioNTech vaccine was 88 percent effective against symptoms of the delta variant two weeks after the second dose, compared with 93 percent against the B.1.1.7 variant, also known as alpha.
Two doses of AstraZeneca-Oxford were found to be only 60 percent effective against Delta symptoms of COVID-19, compared to 66 percent against Alpha.
A single dose of both Pfizer and AstraZeneca was only about 33% effective against delta.
Experts say it’s important to remember that the study looked at the vaccine’s ability to prevent symptoms of COVID-19, which can range from mild to severe, and early estimates of the vaccine’s efficacy against variants don’t tell the whole story.
“A single dose of the vaccine, whether it’s Pfizer or AstraZeneca, still provides a great deal of protection against severe disease and certainly against hospitalization,” said Professor Jason Kendracchuk, associate professor and Canada’s chair of research in emerging viruses at the university. Manitoba.
“Yes, we still need to get two doses, but you know what? Even with one dose, these vaccines work amazingly.”
Kindrachuk says that while Delta reinforces the need for full vaccination of high-risk individuals, such as older and immunocompromised Canadians, getting shots in as many arms as possible will continue to reduce community transmission and the prevalence of variants in general.
“Any group that has not been vaccinated is a gunpowder box waiting to explode, push a lot of cases, hospitalization and new variants,” said Professor Alison Kelvin, associate professor at Dalhousie University and a virologist at the Canadian Vaccine and Vaccine Center. and the Saskatoon Infectious Diseases Organization.
“The best thing we can do is stick to the vaccination plan and continue to follow it until our entire population is covered with not just one, but two doses. That would be the most effective strategy — not trying to get too caught up in the drama of the new alternative.”
Watch | How does variable delta affect vaccine release and reopening?
Two infectious disease specialists answer questions about the Delta variant of coronavirus – first identified in India and also known as B.1.617 – including how it might affect vaccine release and reopening plans in Canada. 5:12
A single dose has “significant” protection.
New Canadian research from the British Columbia Center for Disease Control (BCCDC) also confirmed the efficacy of only one dose of mRNA vaccines against variants and provided new insight into the gamma variable, also known as P.1, for the first time.
Pre-print study, which has not yet been peer-reviewed, found that a single dose of Pfizer or Moderna reduced the risk of COVID-19 for elderly people by about two-thirds during the peak of the spring wave in British Columbia.
The observational study looked at nearly 17,000 people aged 70 and over between April 4 and May 1 — a critical time when both alpha and gamma accounted for about 70 percent of the county’s spread cases.
The researchers also concluded that a single dose of protection for the elderly was “slightly reduced” against alpha and gamma, which they said “enhance” Canada’s decision to postpone the second doses COVID-19 vaccines at a time when supply is limited.
Dr. Danuta Skoronsky, chief of epidemiology at the Centers for Disease Control and Prevention (BCCDC) and lead author of the study said.
“It’s especially meaningful because this one-dose protection was provided during that big third wave – the peak of the epidemic for us in British Columbia”

Skowronski says the study provides the world’s first estimate of a vaccine’s efficacy against a gamma variant and is made possible by the unique location in which BC finds itself, with multiple variants circulating at the same time unlike anywhere else in the world.
“We were able to elicit and show that protection was maintained against P.1, which has remained an open question globally,” Skoronsky said. “So we have addressed this question and shown protection similar to B.1.1.7.”
While BCCDC researchers were unable to analyze the vaccine’s efficacy against the delta variant, which was not widespread in Canada at the time, Skowronsky says the team had their sights set on it in the near future.
“Looking at the data, we can be optimistic that we’ll get a good percentage of efficacy against Delta,” said Kelvin, who was not involved in the study.
“Of course we want everyone to get the second dose but I’m still very optimistic.”
But Skowronski cautions Canadians not to draw too many conclusions from data emerging from the UK on the delta variant, or any one study, due to the fact that they are largely observational and need to be supported by real-world immunology research, which measures immune responses elicited by a vaccine.
“It’s a signal of concern related to a variety of concerns that require further evaluation, and that’s why we’re in the process of doing so,” she said. Then we can respond.
Get the second dose
Experts agree that the biggest threat to Canadians right now isn’t variables – despite the staggering pace of research being released around the world – not vaccinating at all.
“So far for the variables we’ve had, which has been an initial shock and awe and then some stabilization in that, we haven’t seen a significant impact,” Skoronsky said.
“Ultimately, we would still like to have the second dose and this helps us consolidate and understand why this might be necessary.”

Kelvin says the decision to delay second doses in Canada allowed one more dose to be covered, ultimately preventing the virus from infecting more people, increasing hospital admissions and deaths and possibly stopping new variants from emerging here.
“What we want to monitor is: Are these viruses changing dramatically? … We want to stay informed with the new variants,” she said.
“What we can all do is vaccinate and try to reduce our contacts to reduce the chance of the virus mutating – that will be the biggest role we can play in controlling variants.”
Kelvin says if Canada continues to reduce levels of COVID-19 across the country, we should be able to maintain low levels of transmission in the community — which will be driven in large part by pockets of unvaccinated people.
“We are in a very different situation than we were definitely in the early parts of this year,” Kendracchuk said.
“Vaccinations will keep coming and once we get that far, things will change very, very quickly. I think they are already, but I think they will change dramatically in the next few weeks.”
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.
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