In Canada, the number of highly contagious Omicron variants is increasing, and the immunity from previous vaccinations and infections is weakened, so the timing of the next COVID-19 vaccine is this. Can be more important than that. Another surge.
Canada is once again a hotbed of variants, BA. 2.12.1 currently accounts for more than 40% of COVID cases, BA. 4 and BA. 5 is rapidly becoming established at 10% or more. Total cents in late May — a significant increase from less than 1 percent a week ago.
ButThe latest available federal datais a few weeks old, and modeling expert CBC news is BA. I talked to estimate the true percentage of 4 and BA. Five cases are over 20% and can reach 50, one of which can become dominant in the coming weeks.
"COVID-19 has shown us that there may be more surprises in the last few years," Canada's Director of Public Health, Dr. Teresatam, reported on Friday. I mentioned at the press conference.
"The virus is still prevalent in Canada and internationally, and factors such as viral evolution and weakened immunity are expected to affect future COVID-19 activity.
Preparing for a "potential resurrection"
Tam says that COVID's progress in Canada is not easy and authorities are "potential resurrection" As Omicron's subvariants, who said they are preparing for a potentially "potential resurrection," are fighting for control, there will be "serious consequences" in the future, and new variants may still emerge. I have.
"Omicron is evolving and very different from pre-Omicron vaccines and infectious diseases. The type of immunity you get is a completely different beast," modeling and modeling. Said Sara Otto, an expert on. Evolutionary Biology at the University of British Columbia.
"And what we see in vaccine protection is not as recent doses as the last dose, which is that neutralizing antibodies are in our blood. Flow, they are not aware of the virus either. "
That's why virologists and immunologists are timing their next shot ahead of another potential wave. Or the timing when new variants start to rise in Canada is so important that we try not to catch them. Deploy the dose by scrambling in the midst of a rapidly deteriorating wave — as in December whenOmicron first hit.
When do you need a fourth dose?
Canada's National Advisory Board on Immunity (NACI)was the second booster in April to seniors over 80 and other vulnerable groupsWas strongly recommended, but it was not recommended. Fourth shot for all Canadians.
The reason for that decision may have come down to timing, whereis a sub-mutant of Omicron and a a quieter range of summer COVID activityspends time on us before another vaccine needs to be deployed.
However,NACI guidancealso recommends that eligible individuals wait for a second booster 6 months after the last dose. .. And the current epidemiology "and its" shorter intervals "may be needed if another wave hits.
"Once you start seeing BA. 4 and BA. 5 lead to an increase in cases, you'll need to be agile and get boosters, but that's this waiting game." Said Otto.
"The longer you wait for the vaccine, the more recent the vaccine will be and the stronger it will be when the next wave occurs, so months before the next wave. I don't want to be vaccinated against. Canada is really pushing for vaccination at the beginning of the wave. "
Otto is BA in Canada. 4 and BA. I said it's likely that another wave caused by 5 will occur, but in some states likeit's still unclear how bad it has been and it's already started. There is none. OntarioandBritish Columbiahave recently seen increased COVID wastewater monitoring.
May run out of updated vaccine
Virologists and immunologists have also adapted to the original strain of the virus Boosting with a conditioned COVID-19 vaccine may no longer be sufficient and may require an updated vaccine to blunt another potential wave in the coming months. I have.
Moderna's bivalent vaccineis one of the strategies many expect, but experts say{83. Therefore, I am worried that targeting the original Omicron strain may not be enough. } Study
The experimental vaccine combines Modana's original shot with protection against Omicron, andpreliminary dataI've shown it to work, but in the real world it hasn't been tested against other subvariants yet.
Watch | Moderna vaccines targeting Omicron are promising:
Dr. Samir Gupta, a pulmonologist in Toronto, explains how Moderna's new vaccine is planning to provide broad protection against multiple mutations in the coronavirus. Moderna's dual variant booster is currently being tested.
"I don't think you'll see a big advantage of Ottoron-specific booster boosts over regular (original) stock boosters," Otto said.
"Both methods help boost antibody levels, but I don't think they can raise them any further in a way that helps neutralize Omicron."
'Need a better long-term strategy'
University of Toronto immunologist Jennifer Gomerman states that Omicron-specific boosters may be effective against real-world Omicron submutants. However, only if the virus is not valid. Throw something else at us in the coming months.
"If Omicron is basically all the tricks the virus has left, then certainly we have a virus that is very different from what we originally had, so it's based on Omicron. I think it makes sense to get vaccinated. "
"The concern is whether the virus still has enough space to create a new version that is completely different from Omicron, and that's what we want.
Will Alison Kelvin, a virologist at the Canadian Vaccine Center and Sascatoon's vaccine and infectious disease tissues, protect the bivalent vaccine from the currently circulating Omicron submutants? Please say that it is a "big problem". ""
"At this point, I think we need to expect new variants, whether they are new variants of Omicron or completely new variants," she said.
"We need a better long-term strategy. Personally, I don't think bivalent vaccines are a sustainable strategy because we've seen viruses. Once to predict what the variant will be. "
According to Gommerman, thenasal boosteris not yet available, but another arm of the immune system. Targeting may increase protection from infection. McMaster Under development, including a university team, but may still be years away.
See | McMaster University Develops Nose COVID-19 Vaccine:
Professor Fiona Smile of McMaster University in Hamilton, Ontario, is conducting two trials of a new inhaled aerosol drug intended as a COVID-19 booster vaccine.
New variants may change booster timing
Canada is currently aiming for a current generation of vaccine strategy You need to decide if it's to defend against a serious COVID, or , says Gommerman, until a new vaccine or variant changes the game to completely prevent infection.
"If your goal is to prevent infection, we will need to continue boosting forever," Gommeman said. "But if the goal is to protect the vulnerability, we're already doing that."
Gommerman said the COVID level soared and the vulnerable group was at risk. He said he would not receive a fourth dose unless he knew there was a compelling public health reason, such as being exposed and in time. Reduced immunity to infection.
"But I know that my immune protection in the form of immunological memory will keep me away from the hospital," she said. "It won't necessarily prevent me from staying home for a week, but it will keep me away from the hospital, and it's designed to be a vaccine.
Otto said that "the vast variety of viruses maintained worldwide" and that Omicron emerged independently of other variants such as alpha and beta. Given the facts, Delta said it is likely that new variants will continue to emerge.
"Omicron has already seen its substantial evolutionary changes. I'm saying, don't underestimate other strains that are still in circulation worldwide. "She said.
"We are in a game of Whac-A-Mole and I don't know where the next mole will come."