The announcement that the coronavirus strain engulfing Britain could be both more deadly and transmittable has raised new concerns about the variant that has spread to dozens of countries.
Initially, British experts said their evidence suggested that the new species circulating in the UK – one of many that has surfaced internationally in recent months – is between 50 percent and 70 percent more transmissible.
On Friday, however, the government said the new variant could also be 30-40 percent more deadly, although it stressed that the review was based on sparse data.
What has changed?
In mid-January, two separate studies from the London School of Hygiene and Tropical Medicine and Imperial College London were presented to the UK’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG).
They paired data from people who tested positive for the virus in the community – rather than in the hospital – with death data and found an increase in the risk of death of about 30 percent associated with the new strain.
The groups used slightly different methods, but both matched people with the new variant with those with the older variants, taking into account other variables such as age and location and control for hospitals under pressure.
Other studies from Exeter University and Public Health England also found higher deaths, and both came with even higher numbers.
Based on these analyzes, NERVTAG said there was “a realistic possibility” that infection with the new variant is associated with an increased risk of death compared to previously circulating variants.
The increase in transmissibility of the variant is already a cause for concern, because the more people infected with the virus, the more people become seriously ill and run the risk of death.
Unfortunately, it appears that this virus could be both “more contagious and potentially more deadly,” John Edmunds, a professor in LSHTM’s Center for the Mathematical Modeling of Infectious Diseases, told a news conference Monday.
“So unfortunately it’s a really serious turn,” he said.
How reliable are the findings?
Researchers said there were still uncertainties in the data and said the picture would become clearer in the coming weeks.
Edmunds said the findings were “statistically significant.”
But he said that while the studies used information from those tested in the community, most people who die from COVID-19 go straight to the hospital and get tested there.
Researchers do not yet have that hospital information.
NERVTAG said this backlog of data could be why the studies found no evidence of an increase in hospital admissions of people with the new variant, which seems to conflict with the findings of increased disease severity.
It also said that the death rates used in the study accounted for only 8 percent of the total deaths during the study period and that the results “may therefore not be representative of the overall population.”
Why more deadly?
Researchers think it could be the same set of mutations that made it more contagious – although all stress needs more research.
One mutation in particular increases the virus’s ability to adhere more strongly to human cells and NERVTAG head Peter Horby, an emerging professor of infectious diseases at the University of Oxford, said there is some evidence it means it could get easier to get infected.
“ Then if it can spread between cells in the lungs much faster, that can increase the rate of disease and the rate of inflammation, which can then evolve faster than your body can respond to, so it could be both hallmarks of the virus. can explain, ”he said.
Bjorn Meyer, a virologist at the French Institut Pasteur, told AFP the problem could be a viral load.
“The virus may not have evolved to be more deadly as such, but it may have evolved to grow more or better, which in general could do more harm to a patient,” he said.
Does this affect treatments?
Horby, who also leads the Recovery study – which identified the steroid dexamethasone as effective for critically ill hospital patients – said there was “no evidence” that treatments would be less effective.
Anti-inflammatories such as dexamethasone “should work equally well because it is not related to the virus but to the host’s response,” he said.
Horby said general improvements in therapies and treatments – including things like better respiratory support strategies in hospitals – have lowered the death rate since the first wave and may even “make up for any difference with this new variant.”
As far as vaccines are concerned, a preliminary study this month from Great Britain and the Netherlands found that the variant would not be able to evade the protective effect of current vaccines.
Pfizer / BioNTech and Moderna have also published early research suggesting their vaccines would still be effective against the strain.
Aren’t viruses weakened as they spread?
Scientists have tried to challenge the belief that the virus will become less virulent as it progresses to become more contagious.
The virus that causes COVID-19 is already “very good at transmitting,” said Emma Hocroft, an epidemiologist at the University of Bern.
“So I don’t think we can make this assumption that it wants to be less serious. I don’t want to downplay that it’s serious for a lot of people, but for the majority of people it’s not serious,” she said. AFP.
She said the ability to transmit before it kills was “a really low bar,” citing diseases like measles and HIV that are still equally dangerous.
Graham Medley, a professor of Infectious Disease Modeling at LSHTM, told Monday’s press conference that despite uncertainties in the new studies about the new variant in the UK, they should dispel the idea that it would become less virulent.
“It is certainly not the case that this is a more benign virus,” he said.
© Agence France-Presse