Yet more unnerving research is linking a fast-spreading variant of the virus that causes COVID-19 with a higher likelihood of dying.
The latest findings come from a
, in which researchers estimate the variant technically know as B.1.1.7, the so-called U.K. strain, is, on average, 55 per cent deadlier than earlier versions of the virus.
The findings are based on an analysis of more than one million people who tested positive for COVID-19 in England between September 2020 and February 2021. Researchers compared death rates between those who had B.1.1.7 infections and those infected with earlier strains, adjusting for age, ethnicity, sex and other factors. They only compared death rates among people who were tested on the same day and lived in the same city or town, to control for changes in testing rates and hospital pressures.
People infected with the variant were between 39 and 72 per cent more likely to die.
The absolute risk of death remained low, increasing, for example, from 0.6 to 0.9 per cent, for 55- to 69-year-old males.
“We don’t want this 55 per cent number to scare people into thinking ‘this is a big risk for me,’” unless people are elderly or otherwise very sick, said lead author Nicholas Davies, an epidemiologist with the London School of Hygiene & Tropical Medicine.
But there was already evidence the variant is more contagious — between 43 and 90 per cent more transmissible, depending how it’s measured, earlier work by Davies and his colleagues found.
Add in that it is seemingly deadlier, “and that really does add up over an entire population,” said Davies.
Davies is a native of Sault Ste. Marie, Ont. For the past 10 years, he’s lived in the U.K., where the B.1.1.7 variant spread swiftly, from the county of Kent, in southeast England in early October, to London, and to the rest of the U.K. by December’s end.
It now accounts for more than 99 per cent of COVID-19 infections in the U.K., which saw as many COVID-related deaths — some 42,000 — in the first two months of this year as were experienced in the first eight months of the pandemic. “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,” Davies said.
“And yet we’ve had this huge burden of death since B.1.1.7 arose.”
The same variant, scientists warned last week, is poised to drive a third surge of infections in Ontario, where hospitalizations and ICU admissions have begun to creep up. As of Monday, the new “variants of concern” accounted for 49 per cent of confirmed COVID infections in Ontario. The reproductive number — the number of people each infected person goes on to infect — was 1.41. It needs to be below one to slow the spread of the virus.
The Nature paper comes days
using the same data over a slightly different time period, and using a different statistical method, estimated the B.1.1.7 strain could be 32 per cent — to an alarming 104 per cent — more deadly than previously circulating variants (the increased death risk in the “largely unvaccinated population” averaged out to 64 per cent.)
The emergence of the variant, and others identified 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,” the authors of that study wrote in the British Medical Journal.
So far, all the vaccines that have been tested against B.1.1.7 have shown good protection against it.
Taken together, the data are rattling some scientists, who are warning the variants could spark a third surge of COVID-19 within days in Ontario.
Across Canada, a total of 3,302 people have tested positive for “variants of concern,” the vast majority — 3,031 — the U.K. strain. Some say the reported number of cases is almost immaterial because there is so little genomic sequencing of the viruses. The variant is also spreading quickly in the U.S., in Florida, California and Texas.
While Davies is sympathetic to people who say individual risk is low, “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.”
It’s not clear why those infections are more severe. People tend to have higher viral loads— “the virus replicates to larger numbers within the person,” Davies said — and there’s some evidence that people shed virus for longer periods. It could be that treatments don’t work as well against the variants. “But it’s still not really super clear,” he said. It also appears more infectious across all age groups.
Source: National Post Quebec Nordiques