Why a new coronavirus mutation worries some scientists

Earlier this week, British scientists announced that they had identified a mutant version of the new coronavirus or SARS-CoV-2, the new strain appears to be more contagious than other variants of the virus that have spread around the globe.

But is that the only reason for the alarm?

Scientists have mixed opinions. The mutation of the virus does not appear to be more deadly – although the coronavirus is already comparatively much more deadly than other highly contagious pathogens, such as influenza viruses and colds.

So what does this mutation mean and how will it affect our own lives and public health? Here’s what we know.

Numerous variants of SARS-CoV-2

Far from the only mutation, there are actually many variants of SARS-CoV-2 that have appeared around the world. However, the discovery of this mutant strain – which apparently abounded in the south of England and has existed in samples collected since September – is more worrying. This is because the new strain, known as B.1.1.7, has a relatively higher number of mutations (23). In addition, as B.1.1.7 has spread with unusual virulence in the south of England, epidemiologists believe that the mutations have made the virus more contagious.

The virus is “only twice as infectious – which it does very infectious, “said Salon by e-mail to Dr. Alfred Sommer, dean emeritus and professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.” And some suggestions could primarily increase infection in children, who are much less likely to get seriously ill. “

His view was repeated by Dr. Monica Gandhi, a doctor of infectious diseases and a professor of medicine at the University of California – San Francisco, who wrote to Salon that “this variant seems to be more effective in spreading from person to person, although this increase in transmissibility is still being evaluated. Notably, this strain does not seem to have more virulence or make people sick, although it probably spreads faster.

What does this mutation mean for vaccines?

Currently, it does not appear that this mutation will make the recent vaccines developed by Pfizer / BioNTech and Moderna less effective. The reason is that these vaccines defeat the new coronavirus in a way that the new mutations do not seem to change. The candidates Moderna and Pfizer are mRNA vaccines, which use the synthetic version of mRNA (a single-stranded RNA molecule that completes one of the DNA strands in a gene), so that cells produce proteins similar to those in a given virus and can train the immune system to fight it.

In the case of Pfizer and Moderna vaccines, they train the body to recognize and fight a SARS-CoV-2 protein called Spike, which is visible as small spots coming out of the virus sphere, like thorns on a sea urchin.

“Pfizer and Moderna vaccines produce antibodies that target several parts of the Spike protein,” wrote Dr. Salon Russell Medford, president of the Center for Global Health Innovation and the Global Center for Health Crisis Coordination. “In order to evade immunity, [coronavirus] should develop a variant with multiple mutations targeting the same specific locations of the Spike protein. There is no evidence that this occurs or may occur in B.1.1.7 or other variants. “


However, this does not mean that the mutation is not worrying. Dr. Andrew Rambaut, an evolutionary molecular biologist at the University of Edinburgh, told Science Magazine that of the 17 mutations that B.1.1.7 could develop at once, eight are in the gene encoding the Spike protein on viral surface. Two of them are of particular concern to Rambaut: N501Y, which increases how closely the protein binds to the enzyme that helps the virus enter human cells, and 69-70del, which has been discovered in other versions of the virus that have managed to avoid targeting. by the immune system of immunocompromised patients.

Pfizer / BioNTech also expressed concern that the increased contagion of the English virus could mean that more people will need to be vaccinated to stop it from spreading.

And about those vaccines …

Vaccines are still distributed throughout the United States, although thanks to President Donald Trump who missed an offer from Pfizer / BioNTech, it is possible that only 50 million Americans will be able to receive the vaccine before the summer of 2021. The priority is now , is granted to health workers, residents of care facilities for the elderly and essential professionals whose jobs require them to interact with the public and therefore put them at greater risk of infection.

At the time of writing, more than 77 million people have been diagnosed worldwide, including more than 18 million in the United States. More than 1.7 million people have died worldwide, including more than 320,000 in the United States.