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What you need to know about the P1 variant in Alberta

As the B117 variant quickly becomes the dominant strain in Alberta, another variant — P1 — is now starting to spread.

Coronavirus variant is spreading quickly in B.C.

Laboratory technologists work to sequence the genome of the SARS-CoV-2 virus at the BCCDC in Vancouver. (Ben Nelms/CBC)

As the B117 variant quickly becomes the dominant strain of coronavirus in Alberta, another variant — P1 — is now starting to spread.

The P1 variant was first discovered in Japan, in four travellers who had returned from Brazil. As such, it is often associated with Brazil, where COVID-19 cases and deaths have spiked significantly in recent weeks.

In Alberta, the first two cases were identified in the Calgary zone on March 14. That number grew to 23 on Wednesday. P1 cases have now been detected in every health zone in the province, except for the South zone. 

Some of those cases are linked to work-related outbreaks reported in the past week.

Dr. Deena Hinshaw, the province's chief medical officer of health, said Tuesday that some cases have also been linked to outbreaks at ski resorts in British Columbia. 

Alberta's numbers are small, so far, but there is the potential that P1 could drive significant spread, as it did in neighbouring British Columbia. 

As of Wednesday, 1,023 P1 cases had been detected in Canada, with 878 reported in B.C.

P1 concerns

Like B117, the P1 variant is a mutation of the SARS-CoV-2 virus and spreads quicker than the original strain. The P1 variant has the same N501Y mutation that is found in the B117 and B1351 variants, and has been associated with increased transmissibility

"I think that our understanding about how it's going to behave in Canada is still in evolution," said Dr. Stephanie Smith, director of infection prevention and control at the University of Alberta Hospital. "But certainly from looking at the experience, especially in Manaus, in Brazil, where it was initially discovered, it does appear to be very transmissible."

Early research in a preprint study from Brazil suggested that P1 is 2.5 times more transmissible, but Smith noted that Canada has different demographics, population density, climate and geography, so it's not really known how it will spread here. 

The B.C. Centre for Disease Control said the variant may be able to re-infect people who have previously had COVID-19, and there are concerns that existing vaccines may not work as well against P1.

Some of those concerns come from how the variant emerged. P1 was the main driver behind a second wave of infections in the city of Manaus. The Brazilian city was hit hard by the coronavirus in 2020, and it was estimated that more than three-quarters of the population had been infected, which makes the most recent round of infections more concerning.

"You had this population that was supposedly immune to the wild type of COVID having high rates of P1, which suggested that the antibodies that they made to the wild type weren't effective in protecting them," said Smith.

That waning immunity may have played a role in the re-infections, she said, but the variant's ability to infect people who have already recovered from COVID-19 does seem to be a factor.

There are also concerns that P1 may lead to worse outcomes for young and middle-aged people.

A pre-print study published last month, which has not yet undergone the rigorous peer-review process of scholarly journal, suggested there had been a "sudden rise" in case fatality among young and middle-aged adults in the southern Brazil state of Paraná, driven by the P1 variant.

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Smith said the severity of illness caused by the P1 variant is not fully understood.

"There is some indication that it does cause more severe disease, especially in young people," said Smith. "I think that why that occurs is not fully elucidated. Is it because there are higher viral loads or are there other characteristics of the virus that result in increased severity? I think that's still a little bit unknown. "

Canada's Chief Public Health Officer Dr. Theresa Tam said on Tuesday it's not clear if the P1 variant causes more severe illness, but with more cases there are more people ending up in hospital, including younger people. 

"P1 or the other variants could infect younger populations and could cause severe illness," she said. 

Will vaccines work against P1?

Because P1 is relatively new and trials for most COVID-19 vaccines were conducted before it emerged, it's not fully known how effective they will be against the variant. So far, lab studies have been completed that do show a reduction in the ability of antibodies to neutralize the variant. 

"There's some initial data that would suggest that our current vaccines are not as effective in preventing disease, period, but there is some data to suggest that it still does protect against severe disease and hospitalization," said Smith. 

Tam said Tuesday "we do not have an actual vaccine effectiveness estimate that is solidified, in terms of the evidence," but people should still get vaccinated as they will get some level of protection. 

Last month, Dr. Supriya Sharma, Health Canada's chief medical adviser, said the Johnson & Johnson vaccine was effective against the coronavirus variant first identified in Brazil, as well as the dominant strains circulating in the U.S. and Canada.

Stay vigilant

Smith said Alberta is already seeing spread of the P1 variant and there is potential for more, given the high rate of infection in British Columbia. Unlike international travellers, there is no quarantine required to travel to Alberta from within Canada. 

Fortunately, Smith said, the same methods that prevent COVID-19 infection will continue to work against P1, but Albertans need to stay vigilant.

"I think that we don't need to reinvent the wheel," said Smith. "The same measures that we take to protect us against a wild type and B117 are going to be effective at the point if we for the P1, if we do it properly.

"And I think that is at least what we're seeing in Alberta, is that we're seeing a kind of loosening of people's attention to the restrictions. And this is probably not the time to do that, because we will see transmission and we're seeing young people coming into the hospital very ill."