Posted in:
The United Kingdom, the birthplace of the most well-known variant of the virus that causes Covid-19, has discovered a new mutation that affects certain strains of the disease, such as that found in South Africa and Brazil. further complicates the European epidemiological landscape.
As if that wasn’t bad enough, the UK’s most contagious variant of Covid-19 got worse. British health authorities announced on 2 February that they had detected, on the outskirts of Liverpool and Bristol, “a limited number” of strains presenting with the E484K mutation in the UK variant. A total of about 40 cases were detected.
“It’s the same mutation of the S protein E484K in the UK variant as the other South African, Brazilian and Japanese variants,” Julian Tang, a virus expert at the University of Leicester, told FRANCE 24.
But this time, the cases have not been imported from one of those 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 UK variant independently developed the E484K mutation,” Stoye told FRANCE 24.
The E484K mutation has caught the attention of the scientific community because of the possibility that it could make current Covid-19 treatments, including existing vaccines, less effective. But it does not necessarily mean that the new form of the virus spreads faster.
Antibody resistance
“The 501 change [in the first UK variant], improves the binding of the virus to the cell, facilitating its spread; and 484 improves antibody resistance, “Stoye explained.
There remains the thorny issue of the virus’s resistance to antibodies and, by extension, to vaccines, which stimulate the immune system to produce natural defenses against the disease.
When it was discovered in early January, the E484K mutation caused concern among immunologists because it changes the shape of the “ear” protein (which allows the virus to bind to cells and contaminate them), which could complicate the work of antibodies.
It is very likely that the mutation will make the virus variant better able to evade the body’s blocking antibody response. It can also reduce the ability of current vaccines to protect themselves from infection, ”Lawrence Young, a virologist and professor of molecular oncology at Warwick Medical School, told FRANCE 24 by email.
“This could explain the recent results of Novavax vaccine trials [that showed] while the vaccine was 95.6% effective against the original coronavirus and 85.6% against the UK variant, it was only 60% effective against the South African variant, ”he added.
Researchers and pharmaceutical companies have been working to better understand the implications of the E484K mutation. Initial findings show that vaccines may be a little less potent, but “the conclusion is that in people with a good immune response, protection against the virus should be effective,” said Stoye of the Francis Crick Institute.
But he added that the mutation “was of particular concern to older people who have a lower immune response and produce smaller amounts of antibodies.”
That’s why it’s essential that vaccine injections be together, Stoye warned. The second dose increases the production of antibodies, which can be decisive in combating these new variants. “One shot is not enough, people need to understand that there is still risk after a shot with these variants,” he said.
The discovery in the UK of strains carrying the E484K mutation could weigh on the heated debate in Europe over the waiting period between two shots. Moderna and Pfizer recommend three weeks to a month between administering the two doses, but several countries, including the UK and Germany, have suggested spacing them even further.
Extending the period would allow more people to be vaccinated at least once without having to reserve too many doses for booster. This is a political decision, at a time when there is public pressure on European governments to speed up vaccination campaigns.
But, scientifically, it is risky: BioNTech has made it clear that its vaccine is 52% effective after the first dose. This is barely sufficient according to European recommendations (which require a minimum efficiency of 50%), but this only applies to Sars-CoV-2, without any significant mutation. The British variant could very well take advantage of governments ’efforts to calm its impatient components and spread it.
This article was translated from the original into French.