The appearance in the UK of a new strain of the coronavirus, presented as more contagious than the others, was of great concern in Europe. But nothing seems to indicate that this variant causes more severe forms of the disease or is resistant to vaccines, experts point out.
Is it normal for the virus to mutate?
Viruses, like living things, are endowed with genetic material (DNA or RNA), which can be altered when they replicate (mutations) in the cells in which they spread or by exchanges between viruses (recombinations). In general, this usually has no consequences, but mutations can also give the virus an advantage or disadvantage for its survival.
“There are certainly thousands of variants,” recalls Emma Hodcroft, an epidemiologist at the University of Bern.
“The most important thing is to try to find out whether this variant has properties that affect human health, diagnostics and vaccines,” said Julian Hiscox, professor of infectology at the University of Liverpool, quoted by Science Media Center.
The new strain, which prompted the UK government to sound the alarm, involves a mutation called “N501Y” in the coronavirus spike protein, which allows the virus to attach itself to human cells. penetrate them.
Is this variant more contagious?
According to British Prime Minister Boris Johnson, this species could be up to 70% more contagious, causing many European countries and the rest of the world to shut down their air and train connections with the United Kingdom.
“The UK has seen a rapid increase in the number of covid-19 cases in South East England in recent weeks,” and analyzes show that “a large proportion of cases belonged to” the new mutation of the virus, said the report. Sunday the European Center for Disease Prevention and Control (ECDC).
“The reasons for this increase in infectivity are still unclear. We have yet to find out whether this is due to increased viral replication or better connection to the cells that line the nose and lungs,” said Peter Openshaw, professor of experimental medicine. at Imperial College London, at the Science Media Center.
Emma Hodcroft, for her part, was reluctant to say that the virus could be “70% more contagious” because when estimates are made too early, they can eventually change. “We don’t know much where this figure comes from,” he warned.
In addition, in that region of South East England, “the population’s group immunity is weak and the virus has found ground to develop,” the Deputy Director of the Pasteur Institute’s National Reference Center for Respiratory Viruses explained to AFP. Paris, Vincent Enouf.
How did this species circulate?
It’s hard to say this new form was born in the UK. That country “is the world leader in sequencing […]. So if there is a variant and it reaches the UK, chances are they will detect it, “said Emma Hodcroft, saying that the first batch of that new strain dates back to September.
According to the World Health Organization (WHO), similar forms were found in different countries, such as Australia (one case), Denmark (9), the Netherlands (1) and South Africa. Italy also announced that it discovered a first case on Sunday.
“Although it was not born in the UK, it appears that it developed there, in England,” said Emma Hodcroft.
– Will the vaccine be less effective?
Currently, scientists consider it unlikely that this new strain is resistant to current vaccines against covid-19.
“The idea of the vaccine is to show the entire Spike protein to the immune system, which in this way learns to recognize its many parts,” explains Emma Hodcroft. So, “while some parts change, the rest remain to recognize the virus,” he said.
Vincent Enouf said that “a repertoire of antibodies should suffice.”
“At the moment there is no evidence that this new strain has a higher mortality rate or that it affects vaccines and treatments, but work is underway to confirm this,” added England Chief Physician Chris Whitty. WHO and ECDC came to the same conclusion.
Will it affect the tests?
“Those responsible for the laboratories should check with their suppliers to see if their tests could be faulty” for this new variant, Vincent Enouf emphasized.
According to the ECDC, the change in the Spike protein caused false negatives in some UK testing laboratories, which rely solely on that protein for their analyzes.