British scientists have said that the UK variant of the coronavirus that is behind an increase in COVID-19 infections may not only cause more transmission, but also more lethality – with the risk of mortality around 30% higher than other modifications.
The RA variant – known as B.1.1.7 – is also up to 70% more contagious than other coronavirus variants circulating in the UK and has already been found worldwide. U.S. health officials have warned it could make a major difference there by March.
What new evidence do UK scientists have?
The evidence on the risk of death comes from the UK government’s New and Modern Respiratory Virus Risk Advisory Group (NERVTAG) and is based on four separate studies conducted on the same dataset. The studies link data from COVID-19 trials in the community with deaths from the disease.
Although each analysis showed a slightly different result, all of them showed a higher risk of mortality among people with B.1.1.7 variables than among those affected by variables. other in the UK.
None of the studies suggested that the risk of death is lower.
NERVTAG combined the findings in a model that estimated an average increase in the risk of death of about 30%.
How sure are scientists of the results?
The UK government’s chief scientific adviser, Patrick Valance, said on Friday that there was some “uncertainty” about the mortality rate estimates as the data came from a series of different pieces of information.
The preliminary data come from analyzes of a relatively small proportion of the UK population who were diagnosed with the new disease, said Susan Hopkins, an expert at Public Health England (PHE), adding to that evidence ” from some but not all data.sources “indicate a higher risk of death. “It’s possible we don’t see the whole picture,” she said.
Julian Tang, a clinical clinician at the University of Leicester, also noted that the numbers were small, so the results “may be subject to major changes at a later date”.
But questioning the uncertainty at Monday’s briefing, John Edmunds, professor of mathematical modeling of infectious diseases at the London School of Hygiene and Tropical Medicine, said the findings were “statistically significant” and should be taken into account. give them.
“There’s a lot of evidence and the impact isn’t small,” he said.
“It’s not like this product just … comes up overnight,” he said. “We’ve been working on it for weeks.”
Do we know what could make the new variant more lethal?
Scientists are still not sure about that anymore, but they are trying to find out.
“Evidence of this variability is still emerging and more work is underway to fully understand how it behaves,” PHE’s Hopkins said.
What scientists know, however, is that the new variant has a mutation on part of the virus that makes it more capable of making strong connections to human cells.
“That is the most plausible biological explanation for (both) the observed increase in transmission and, perhaps, the increase in depth that we might see, said Peter Horby, an emerging professor of infectious diseases at Oxford University and chairman of NERVTAG.
Simon Clarke, an associate professor of cell microbiology at the University of Reading, said that this stronger link could be “too strong a defense with the immune system, which causes the worst disease, and could be fatal ”.
How troubling is this potentially higher death rate?
Edmunds, who co-directed one of the analyzes that fed into the 30% greater risk of death estimate, said the evidence was “a very bad turn for the worse”.
“This virus is very serious and needs to be very important,” he said.
PHE confirmed in a statement that the overall risk of death for all COVID-19 infections (across all age groups) is “still low, for both the new variant and the older variant”.