There are COVID-19 cases, hospitalizations and deaths every day A sharp decline The country has reached its highest level since the fall, and vaccine shipments will increase significantly. More than 5.3 million doses Arrived alone next week.

So far More than 28 million doses of vaccine Has been managed across Canada, approximately 72% Of eligible Canadians have at least one chance and are close to 12% There are two.

However, people are increasingly worried about the spread of variants, which has raised doubts about whether we can safely reopen society in Canada’s worst-hit areas, especially in The UK is struggling with a variant called delta or B.1.617.

Although there are many uncertainties ahead, experts say that early data from the UK and a new study just released in British Columbia point to the same way forward-get as many people as possible to shoot as soon as possible.

Variants and vaccines

A recent study by Public Health England (PHE) See how the first dose affects the delta variant.

The study found that the Pfizer-BioNTech vaccine is 88% effective for symptomatic diseases from delta variants two weeks after the second dose, while it is effective against B.1.1.7 variants (also known as alpha) Is 93%.

It was found that two doses of AstraZeneca-Oxford injections are 60% effective for COVID-19 symptoms from delta and 66% effective for alpha.

And a dose of Pfizer and AstraZeneca are only about 33% effective Oppose Delta.

Experts say it’s important to remember that the study looks at the vaccine’s ability to prevent COVID-19 symptoms, which can range from mild to severe, and early estimates of the vaccine’s effectiveness against these variants do not tell the whole story. Happening.

“A dose of vaccine, whether it is Pfizer or AstraZeneca, can actually still provide considerable protection against serious diseases, and of course it can also prevent hospitalization,” said Professor Jason Kindrachuk, assistant professor of emerging viruses at the university and chair of Canadian research. Manitoba.

“Yes, we still need two doses of the vaccine, but did you know? Even with one dose, these vaccines are very effective.”

Kindrachuk said that although delta reinforces the need for comprehensive vaccination of high-risk groups (such as Canadian elderly and immunocompromised persons), vaccinating as many as possible will continue to reduce the spread of community and overall mutations.

Professor Alyson Kelvin, an assistant professor at Dalhousie University and a virologist at the Canadian Center for Vaccinology and Vaccines, said: “Any unvaccinated population is a gunpowder box waiting to explode. It will cause a large number of cases, hospitalizations and new mutations. Infectious Disease Organization in Saskatoon.

“The best thing we can do is to stick to the vaccination plan and continue to implement it until our entire population receives not only one dose, but also two doses. This will be the most effective strategy — don’t try to catch up with the new variants too much. In the drama.”

Watch | How does the delta variant affect the launch and reopening of vaccines?

Single dose has “substantial” protection

New Canadian research from the British Columbia Centers for Disease Control (BCCDC) also emphasizes that even a single dose of mRNA vaccine can effectively combat these mutations and provides new insights Range variants, Also known as P.1, this is the first time.

Preprint researchResearch that has not been peer-reviewed found that during the peak of the spring wave in BC, a single dose of Pfizer or Moderna can reduce the risk of COVID-19 in the elderly by approximately two-thirds

This observational study surveyed nearly 17,000 people aged 70 and over between April 4 and May 1-this is a critical period, and both alpha and gamma accounted for about 70% of cases transmitted in the province .

The researchers also concluded that single-dose protection for the elderly only “minimizes” the effects on alpha and gamma, which they say “enhanced” Canada decided to postpone the second dose Get the COVID-19 vaccine when supplies are limited.

“Even at the peak of the pandemic, even if most viruses are these worrying variants, compared to unvaccinated adults, we found that the risk of vaccinated elderly people is significantly reduced,” BCCDC Epidemiology is responsible for People, the lead author, Dr. Danuta Skowronski, said the research.

“This is particularly meaningful because this single-dose protection was provided during the third wave of the pandemic-our peak of the pandemic in British Columbia”

Skowronski said that this study provides the world’s first estimate of the effectiveness of a vaccine against gamma variants, and it is possible because of the unique location of BC, unlike anywhere else in the world, where multiple variants are spreading at the same time.

“We were able to deduce and prove that the protection of P.1 still exists, which is still an open issue globally,” Skowronski said. “So we have solved this problem and demonstrated protection equivalent to B.1.1.7.”

Although BCCDC researchers were unable to analyze the effectiveness of the vaccine against delta variants that had not yet been widely spread in Canada at the time, Skowronski said the team had set their sights on the near future.

“Looking at the data, we can be optimistic that our effectiveness on delta will reach a good percentage,” 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 warns Canadians not to draw too many conclusions from the data on delta variants in the United Kingdom or any one study, because it is mainly observational and needs to be supported by real-world immunogenicity studies. The study measures The immune response generated by the vaccine.

“This is a worry signal related to a variant of worry that deserves further evaluation, and that’s why we are paying attention to it,” she said. “Then we can react.”

‘Get a second dose’

Experts agree that the biggest threat facing Canadians right now is not mutation—despite the dizzying speed of research published worldwide—it is not vaccinated at all.

Skowronski said: “So far, for the variants we encountered, it was initially shock and awe, and then some solutions. We have not seen a big impact.”

“Ultimately, we still hope to get a second dose, which helps us strengthen and understand why this may be necessary.”

Kelvin said that the decision to postpone the second vaccination in Canada allowed for more single-dose coverage, which ultimately prevented the virus from infecting more people, increasing hospitalizations and deaths, and possibly preventing the emergence of new variants.

“What we want to focus on is: have these viruses changed significantly? … We want to keep up with the latest developments in the new variants,” she said.

“What we can do is get vaccinated and try to reduce exposure to reduce the chance of virus mutation-this will be the biggest role we can play in controlling mutation.”

Kelvin said that if Canada continues to reduce the level of COVID-19 nationwide, we should be able to maintain a low level of community transmission-mainly driven by a small number of people who have not been vaccinated.

Kindrachuk said: “We are in a very different position from the situation at the beginning of this year.”

“Vaccinations will continue to be popular, and once we reach this threshold, things will change very, very quickly. I think they have already happened, but I think they will change significantly in the next few weeks.”

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