The UK, which is already the cradle of the well-known, more contagious variant of the virus that causes Covid-19, has discovered a new mutation affecting certain strains of disease, similar to that found in South Africa and Brazil, further complicating the European epidemiological landscape.
As if that wasn’t bad enough, the more contagious British variant of Covid-19 only got worse. British health authorities announced on February 2 that they had discovered “a limited number” of strains on the outskirts of Liverpool and in Bristol presenting the E484K mutation in the British variant. In total, about 40 cases were detected.
“It is the same S-protein E484K mutation in the British variant as the other South African, Brazilian and Japanese variants,” said Julian Tang, a virus expert at the University of Leicester, FRANCE 24.
But this time, the cases were not imported from any of the three countries, according to Jonathan Stoye, a virologist and head of research at the Francis Crick Institute in London. “What happened in Liverpool is that the British variant independently developed the E484K mutation,” Stoye told FRANCE 24.
The E484K mutation has caught the attention of the scientific community due to the possibility that it could make current Covid-19 treatments, including existing vaccines, less effective. But this does not necessarily mean that the new form of the virus spreads faster.
Resistance to antibodies
The 501 change [in the first UK variant]improves the binding of the virus to the cell, making it easier to spread; and 484 improves resistance to the antibodies, ”Stoye explained.
There remains the thorny issue of the virus’ resistance to antibodies and, in the long run, to vaccines, which stimulate the immune system to produce natural defenses against the disease.
When discovered in early January, the E484K mutation caused concern among immunologists because it alters the shape of the “nail” protein (allowing the virus to bind to cells and contaminate them), which can complicate the task of antibodies.
The mutation “is very likely that the virus variant can better avoid the body’s blocking antibody response. It may also reduce the ability of current vaccines to protect against infection, ”Lawrence Young, a virologist and professor of molecular oncology at Warwick Medical School, emailed FRANCE.
This may reflect the latest results from the Novavax vaccine trials [that showed] while the vaccine had a 95.6% effect against the original coronavirus and 85.6% against the British variant, it had an effect of only 60% against the South African variant, ”he added.
Researchers and pharmaceutical companies have worked to better understand the consequences of the E484K mutation. The first findings show that vaccines may be a little less potent, but “the bottom line is that in people with a good immune response, protection against the virus should still be effective,” says Stoye, at the Francis Crick Institute.
But he added that the mutation was “of particular interest to the elderly who have lower immune responses and produce smaller amounts of antibodies”.
That is why it is important to get the vaccine injections close together, Stoye warned. The second dose improves the production of antibodies, which may be crucial in combating these new variants. “One shot is not enough, people need to understand that there is still a risk of a shot with these variants,” he said.
The discovery in the UK of strains carrying the E484K mutation may weigh on the hot debate in Europe over the waiting time between two shots. Moderna and Pfizer recommend three weeks to a month between the administration of the two doses, but several countries, including the United Kingdom and Germany, have suggested that they be further distributed.
Extending the period would make it possible to vaccinate more people at least once without having to set aside too many doses for booster. It is a political decision, at a time when there is public pressure on European governments to speed up vaccination campaigns.
But scientifically, it’s risky: BioNTech has made it clear that its vaccine is 52% effective after administering the first dose. This is barely enough according to European recommendations (which require a minimum efficiency of 50%) – but this only applies to Sars-CoV-2, without any significant mutations. The British variant could very well take advantage of governments’ efforts to calm their impatient constituents and spread.
This article was translated from the original in French.
