SARS-CpV-2 Mutant Strains Emerging Threat

"We don't want this 55 percent number to scare people into thinking 'this is a big risk for me', [unless people are elderly or otherwise very sick]."

"[...It is seemingly deadlier], and that really does add up over an entire population."

"Over the course of 2020, treatments for COVID-19 had improved so much -- the survival rate by the end of summer was twice as good as the beginning of the pandemic."

"And yet we've had this huge burden of death since B.l.l.7 arose."

"It's still very high for an infectious disease, and we're talking about millions of people getting infected. It's not just something you can ignore."

"...The virus replicates to larger numbers within the person. [Evidence exists that people shed virus for longer periods, so it could be that treatments don't work as well against the variants]. But it's still not really super-clear."

Nicholas Davies, epidemiologist, London School of Hygiene & Tropical Medicine

A doctor speaks with a patient on Monday during a demonstration of a mass vaccination clinic in Cobourg, Ont. Photo by Frank Gunn/The Canadian Press

A paper published in the journal Nature presents the latest findings where researchers estimate the variant technically known as B.1.1.7 more generally called the U.K. strain, averages out to be 55 percent more deadly than the original, early versions of the SARS-CoV-2 virus causing COVID-19. Based on an analysis of over a million people testing positive for COVID-19 in Britain in the period from September 2020 to February 2021, researchers compared death rates between people who had B.l.l.7 infections and others infected by earlier strains.

Those infected with the variant turned out to be between 39 and 72 percent likelier to die from the effects of the mutant COVID strain. Bearing in mind the absolute risk of death is relatively low but increasing from 0.6 to 0.9 percent for 55- to 68-year-old men. Evidence already existed that the variant is more contagious; between 43 and 90 percent more transmissible, according to earlier work by Dr.Davis and his colleagues.

The B.l.l.7 variant spread from the county of Kent in southeast England in early October of 2020 to London, then swiftly on to the rest of the United Kingdom by the end of December. At present, the variant accounts for over 99 percent of COVID-19 infections in the U.K. resulting in as many COVID-linked deaths -- roughly 42,000 in the first two months of the current year -- as had occurred in the first eight months of the pandemic onset.

Last week the same variant, according to scientists' warnings appeared poised to drive a third surge of infections in Ontario. A reality signalled by hospitalizations and ICU admissions increasing. The new 'variants of concern' accounted for 49 percent of confirmed cases in Ontario. Another British study based on the same data as the Nature paper but from the perspective of an alternate statistical method estimated that the B.l.l.7 strain could be 32 percent to 104 percent more deadly than previous variants in circulation.

It was found that the death risk in the "largely unvaccinated population" averaged out to 64 percent. Variants sch as the U.K. model along with others in Brazil and South Africa "highlights the capacity of SARS-CoV-2 to rapidly evolve new phenotypic variants, with mutants that evade vaccines being a real possibility" wrote the authors of the second study, published in the British Medical Journal. All vaccines tested against B.l.l.7 have proven to be effective against COVID-19.

Some scientists warn that the variants are capable of sparking a third surge of COVID-19 in a mere matter of days, in Ontario. A total of 3,302 people across Canada tested positive for "variants of concern" while the vast majority of 3,031 were susceptible to the U.K. strain. Florida, California and Texas are also seeing the spread of the variant. People seek comfort in pointing out that individual risk is low and point to the fact that infections are more severe with higher viral loads.

Masked pedestrians during a surge in coronavirus cases in the San Francisco Bay area in December 2020. A new study suggests a prevalent viral variant there may be more transmissible and lethal.   AP Photo/Jeff Chiu