The announcement that the coronavirus strain across the UK could be more deadly and more transmissible has raised new concerns about the variant that has spread to dozens of countries.
Initially, British experts said that their evidence suggests that the new strain circulating in the UK – one of the few that has appeared internationally in recent months – has been 50% and 70% more transmissible.
On Friday, however, the government said the new option could also be 30-40 percent more deadly, although it stressed that the assessment is based on rare data.
What has changed?
In mid-January, two separate studies by the London School of Hygiene and Tropical Medicine and Imperial College London were presented to the UK New and Emerging Respiratory Threat Advisory Group (NERVTAG).
They linked data from people who tested positive for the virus in the community – rather than in the hospital – to data on death and found a 30% increase in the risk of death 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 pressurized hospitals.
Other studies by the University of Exeter and Public Health England also found higher deaths and both came in even higher numbers.
Based on these analyzes, NERVTAG said that there is a “realistic possibility” that the infection with the new variant is associated with an increased risk of death compared to previously circulating variants.
The increase in transmissibility associated with the variant has already caused an alarm, because the more people the virus infects, the more people will suffer from serious diseases and the risk of death.
“Unfortunately, it looks like this virus could be both ‘more infectious and potentially more deadly,'” John Edmunds, a professor at the Center for Mathematical Modeling of LSHTM Infectious Diseases, said Monday.
“So, unfortunately, it’s a serious turn for the worse,” he said.
How reliable are the findings?
The 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 of COVID-19 go straight to the hospital and are tested there.
Researchers do not yet have this information about the hospital.
NERVTAG said that this data gap could be the reason why studies have not found evidence of an increase in hospitalizations of people with the new variant, which seems to contradict the findings of an increased severity of the disease.
He also said that the mortality data used in the research cover only 8 percent of all deaths in the study period and said that the results may therefore not be representative of the total population.
Why more deadly?
Researchers believe it could be the same set of mutations that made it more infectious – although all the stress needs more study.
One mutation in particular increases the virus’s ability to cling more strongly to human cells, and NERVTAG chief Peter Horby, an emerging professor of infectious diseases at Oxford University, said evidence suggests this could make the infection easier.
“If it is then able to spread between cells much faster in the lungs, this can increase the rate of the disease and the rate of inflammation, which can progress faster than your body can respond, so it could explain both features of the virus,” he said. said.
Bjorn Meyer, a virologist at the Pasteur Institute in France, told AFP that the problem could be viral load.
“The virus may not have evolved to be more deadly as such, but it could have evolved to grow more or better, which could cause more damage to a patient in general,” he said.
Does it affect treatments?
Horby, who is also leading the recovery process – which has identified the steroid dexamethasone as effective for critically ill patients – said there was no “evidence” that the treatments would work less well.
Anti-inflammatory drugs, such as dexamethasone, “should work just as well because it’s not related to the virus, it’s related to the host’s response,” he said.
Horby said overall improvements in therapies and treatments – including things like better hospital respiratory support strategies – have lowered case mortality rates since the first wave and could even make up for any difference with this new variant.
With regard to vaccines, a preliminary study conducted this month in the UK and the Netherlands found that the variant will not be able to evade the protective effect of current vaccines.
Pfizer / BioNTech and Moderna have also launched early research, suggesting that their vaccines would still be effective against the strain.
Do viruses not weaken as they spread?
Scientists have tried to challenge the belief that the virus will become less virulent as it evolves to become more infectious.
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 that assumption that it wants to be less severe. I don’t want to downplay that it’s severe for a lot of people, but for most people, it’s not severe,” she said. AFP.
She said the ability to transmit before killing was “a very low bar”, citing diseases such as measles and HIV that remained just as dangerous.
Graham Medley, a professor of infectious disease modeling at LSHTM, told the press on Monday that, despite uncertainties in new studies on the new variant in the UK, it 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