Canada BA.4, BA.5: What We Know About Two New Omicron Subvariants-National

The World Health Organization (WHO) is closely monitoring two new ones COVID-19 (new coronavirus infection) Subvariant of OmicronA highly contagious mutant strain of concern that is currently predominant worldwide.

Since January, more than 300 cases of BA.4 and BA.5 sublineage have been reported in several countries. cov-lineages.org.. Most of these cases have been detected in South Africa.

As of May 3, Canada detected three cases – two in BA.4 and one in BA.5, the Public Health Agency of Canada (PHAC) told Global News on Friday.

“As with all new sub-strains of COVID-19, Public Health Agency of Canada (PHAC) scientists, along with national and international experts, have worked with BA.4 and BA.5 sub-strains.” PHAC spokesman Anne Genier said in an email statement.

WHO started tracking BA.4 and BA.5 in mid-April.. They have been added to the previously discovered subvariants BA.1 and BA.2, the latter dominating the global spread of COVID-19.

As part of their evolution, all viruses mutate over time and have subvariants that have a different genetic makeup than the original variant but have a common origin.

WHO states that BA.4 and BA.5 have acquired some additional mutations that may affect their properties.

So far we know about these subvariants:

According to WHO, BA.4 and BA.5 are driving a surge in new COVID-19 cases in South Africa.

Last week, over 32,000 new infections were reported in the country. This represents a 67% increase from the previous week. Weekly WHO update It was released on May 4th.

South African data show that BA.4 and BA.5 appear to have a growth advantage over other substrains of Omicron, WHO told Global News.

Dr. Donald Vinh, an infectious disease specialist and medical microbiologist at McGill University Health Center (MUHC), said that BA.4 and BA.5 are about 10% more infected than BA.2 due to additional mutations. It states that it has a high sex.

“The only way a virus can mutate and propagate is whether it is transmitted within the community,” he said.

“Therefore, the logical and scientific solution is to mitigate local infections by all necessary means,” Vinh urged indoor masking, avoidance of crowded areas, ventilation and vaccination. ..

Globally, the number of cases and countries reporting detection of these subvariants is increasing, the United Nations Health Agency said in its weekly update.

As more cases have been reported, experts say it’s only a matter of time before it replaces the previous strain and begins to dominate.

“I’m sure they’ll take over as they’re starting to grow in South Africa. Seeing that they (cases) are starting to grow means they’re taking over the previous one,” said Horatio. Dr. Bach said. , An infectious disease expert at the University of British Columbia.

Scientists are trying to determine if BA.4 and BA.5 can cause more serious illness in infected people and lead to increased hospitalization.

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Many studies are underway to determine the severity of the disease in the laboratory.

“It’s too early to know if these new subvariants can cause more serious illness than other Omicron subvariants, but early data show that vaccination could cause more serious illness and death. It suggests that we will continue to prevent it, “WHO Secretary Dr. Tedros Adanom Gebreisas said in virtual news. May 4th meeting.

WHO told Global News that hospitalizations in South Africa have increased somewhat, which can be expected if the number of cases increases.

Vinh said it is “very important” to carefully monitor how BA.4 and BA.5 affect hospitalization not only in South Africa but also in Europe.

“What we’ve seen in the last six waves is that we’re not only predicting what’s happening in Europe, but also before what’s happening in Canada’s … region.” Vinh said.

Preprint survey The unpeer-reviewed one was released on May 1, and BA.4 and BA.5 can dodge antibodies from previous infections enough to trigger a new wave, but COVID-19. We conclude that vaccinated people are far less prosperous.

“I’m always worried if there are mutants that are a bit more contagious and can dodge antibodies generated from previous waves,” Vinh said.

South African scientists took blood samples from 39 participants who were previously infected with the original BA.1 Omicron strain when they first appeared at the end of last year.

Fifteen people were vaccinated. Eight were Pfizer shots, seven were J & J shots, and the other 24 weren’t.

“Vaccinated groups show about five times higher neutralization capacity than BA.4 and BA.5 and can decline as levels decrease, but need better protection.” The author of the study states.

In unvaccinated samples, exposure to BA.4 and BA.5 reduced antibody production by almost one-eighth compared to the original BA.1 omicron strain. Blood from vaccinated people showed a one-third reduction.

Studies are underway to determine how effective preimmunity constructed by either infection or vaccination is to protect against BA.4 and BA.5 compared to other submutants. is.

“Like all substrains that fall into the Omicron category, there is some degree of antigenic escape,” said Dr. Maria Vankelkov, COVID-19 Technical Lead at WHO. May 3rd Twitter video..

Bach said that even if you are vaccinated, you can still be infected with new variants.

Still, experts hope that current vaccines will help prevent serious illness and death and encourage people to vaccinate.

“On a global scale, it means that the entire world needs to be properly vaccinated with COVID to reduce the incidence of infections and variants,” Vinh said.

WHO emphasizes the need for countries to continue testing and sequencing new variants.

“In many countries, we don’t really know how the virus is mutating. We don’t know what’s coming next,” said WHO Chief Ghebreysus.

The Government of Canada is conducting strong monitoring programs in states and territories to identify Canadian COVID-19 variants, including the Omicron variant of concern and its substrains, PHAC Genier said. I am.

However, experts say the state has not adequately tracked new variants and is “significantly underestimating” actual cases in the country.

“We need to actively monitor what’s circulating in each state and community,” Vinh said.

“When the Public Health Agency of Canada says it has identified three cases together across the country, it’s just a big underestimate of what’s really outbreak.”

— Use files from Reuters