The United Kingdom, already the cradle of the famous more contagious variant of Sars-CoV-2, discovered a new mutation on Tuesday affecting certain strains of the Covid-19 virus. It is the same as the one in South Africa and Brazil, which further complicates the European epidemiological landscape.
As if that wasn’t enough. The English variant of Covid-19, more contagious, has just acquired a new weapon. TheBritish health authorities announced, Tuesday February 2, to have detected in this variant, on the outskirts of Liverpool, “a limited number of strains presenting the E484K mutation”. There would have been a40 cases detected.
“It is the same mutation as that which was observed on the South African, Brazilian and Japanese variants of the virus”, specifies Julian Tang, virologist at the University of Leicester, contacted by France 24. In this case, he these are not cases imported from one of these three countries. “It seems that it is the British strain which began to develop this mutation on its own in this small number of cases”, specifies Jonathan Stoye, virologist and head of research at the Francis Crick Institute in London, contacted by France 24.
This discovery is “worrying” and the evolution of this British variant must be followed very closely, Judge Julian Tang. The E484K mutation has indeed caught the attention of the scientific community because it could make current treatments against Covid-19, including vaccines, less effective.
Thorny issue of antibody resistance
Clearly, there is a strain of Sars-CoV-2 starting to circulate in the UK which “has, to put it simply, the first mutation allowing it to spread more quickly and a second – the new one – making the antibodies less effective. ”, Summarizes Jonathan Stoye.
For this expert, this does not bode well for a rapid rise in this new form of the virus on British soil. “I don’t think it spreads faster than the main variant because the mutation that makes it more contagious is the one that was already present in the UK,” says the head of research at the Francis Crick Institute.
There remains the thorny question of its resistance to antibodies and, therefore, potentially to vaccines, the role of which is precisely to stimulate the immune system so that it produces these natural defenses against the disease. When it was discovered in early January, the E484K mutation of Sars-CoV-2 had worried immunologists because it introduced changes to the appearance of the “spike” protein (which allows the virus to cling to cells to contaminate them. ) which may complicate the task of antibodies. “They might have a harder time recognizing and attaching to the virus to fight it”,then summarized in France 24 Lawrence Young, virologist and professor of molecular oncology at Warwick Medical School.
Since then, researchers and pharmaceutical companies that develop vaccines have worked to better understand the implications of the appearance of the E484K mutation to fight against the pandemic. The first findingsare less alarmistthatwhat we could have feared: the vaccines could be a little less effective, but “the individuals in good health and whose immune response is strong enough should be protected nevertheless”, specifies Jonathan Stoyes.
Two injections of vaccines close together, otherwise nothing?
This is why, according to him, it is essential to make two injections of vaccines together. The second dose acts as an enhancer for the production of antibodies, which can be decisive in combating these new variants. “People who have received their first injection should not think they are protected, especially in the face of these new, more resistant variants,” says Jonathan Stoyes.
In this sense, the discovery on British soil of strains doped with the E484K mutation could weigh on the currently heated debate in Europe as to the timeframe for the two injections. Several countries, including the UK and Germany, suggested spacing them out further.London opted for 12 weeks while Moderna and Pfizer advocate three weeks to one month between the administration of the two doses.
The extension of the delays makes it possible to vaccinate as many people as possible at least once without having to set aside too many doses for the booster. A political choice which makes it possible to appease public opinion when it accuses the authorities of carrying out a too slow vaccination campaign. But it is scientifically risky: BioNTech clarified that the effectiveness of its vaccine rises to 52% after the first dose. This is barely sufficient with regard to European recommendations (which set a minimum efficiency of 50%), but this only applies to Sars-CoV-2 without significant mutation. The British variant could very well take advantage of this desire of the leaders to calm the popular sling to spread.
Source : france24.com