BA.2 subvariant could cause Alberta's 6th wave by May: biologist

With the emergence of a new subvariant of COVID-19, one developmental biologist is questioning if dropping restrictions and mask mandates in Alberta was the right call.

The latest version of the coronavirus, which scientists refer to as BA.2, is considered stealthier than the original version of Omicron, now known as BA.1, as particular genetic traits make it difficult to detect.

On Wednesday, Alberta's top doctor said the province was monitoring the latest strain of COVID-19.

"Over the past couple of months, we've seen that the proportion of our cases that are BA.2 is slowly increasing," said Dr. Deena Hinshaw, chief medical officer of health.

"We are still at less than half of our new detected cases that are BA 2. So, BA 1 is still our dominant strain in Alberta," she added.

Lisa Glover, Alberta Health spokesperson, said in a statement to CTV News Edmonton that less than 40 per cent of identified positive cases are BA.2.

"Although inherently more transmissible than BA.1, so far there is no evidence of it causing more severe disease than BA.1, based on real world data on clinical severity from South Africa, the United Kingdom, and Denmark and Ontario," Glover added.

• Alberta ditches proof-of-vaccine program at midnight, masking for students Monday

According to research from the University of Massachusetts, it is unclear how significant these mutations are and how it will impact people who experienced the original Omicron variant.

For Gosia Gasperowicz, University of Calgary developmental biologist, the new mutation should be concerning, particularly since Alberta has no more public health measures to slow case growth.

"Removing all the protections that we have is a folly now with what we know about BA.2 and we know how fast it grows in other jurisdictions," Gasperowicz told CTV News.

"What we have seen in other countries is that while BA.2 seems to transmit more effectively, it does not seem to be a higher risk for severe outcomes," Hinshaw said.

On Thursday, Alberta reported 627 confirmed cases of COVID-19. Hospitalizations declined by 22 to 967 patients, including 67 people in intensive care. Six more people had died of the disease.

The province now has 6,552 known active cases.

SIXTH WAVE IN ALBERTA?

Based on estimates reported from other jurisdictions that BA.2 has approximately a 40% transmission advantage compared to BA.1, Gasperowicz calculates an expected growth rate of BA.2 to be 20 days doubling time, which is similar to what is observed in Europe. Gasperowicz says a sixth wave will most likely surge in May — or earlier

"At this rate of growth, around May 24 or earlier, we could have 2,000 daily cases, and then June 16 around 4,000 cases," she said. "It could be earlier or later.

"We will get to these numbers. There's no reason to think that we won't," Gasperowicz added.

Hinshaw recognized that BA.2. caused cases and hospitalizations to increase in European countries like the United Kingdom and Denmark, but those surges remained at a point where they were "manageable" within those countries' health-care systems.

"What I think we should expect is to have fluctuations in transmission over the coming months," Hinshaw added. "We should expect to see COVID remaining with us for the next several months, at I would suggest, relatively similar levels of transmission.

"Given our current levels of vaccine coverage and the relatively recent experience with BA.1, I don't anticipate that we would see the same magnitude of impact. However, we will continue to monitor and of course, respond to any changing data if that does not prove to be true."

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• New studies bring BA.2 variant into sharper focus
• As 'stealth Omicron' advances, scientists are learning more

MASKING UP

Gasperowicz says maintaining a mask mandate with requirements for N95 respirators would help slow down spread.

"Even if BA.2 wouldn't be much more severe than BA.1, it's still severe enough to kill many people," she said, adding that at least 6,500 deaths were reported in Canada in the first three months of the Omicron wave.

"It's not something mild," she said. "If we compare it to the flu seasons in the years prior to COVID, it was usually less than 300 deaths in the whole season in Canada."

Furthermore, the developmental biologist said severe outcomes and hospitalizations are not the only severe outcomes to be worried about as scientists are still learning the impacts of long-COVID.

"We still don't know how much harm can happen from being infected multiple times," Gasperowicz said. "It's not a mild virus. It's not benign. It's not like a flu.

"It's not like a common cold," she added. "It's really dangerous. It's a virus that affects not only our pulmonary system but also our brain, it can damage our heart and damage our kidneys."

OTHER COVID-19 RELATED NEWS 

Alberta will only provide a COVID-19 update once a week on Wednesdays, going forward. The change, also announced Wednesday, comes as "we shift out of crisis mode and move toward endemic response," Copping said. 

With files from CTV News Toronto's Phil Tsekouras and The Associated Press