The appearance in the United Kingdom of a new strain of the coronavirus, presented as more contagious than the others, generated strong concern in Europe. But nothing seems to indicate that this variant causes more severe forms of the disease or that it is resistant to vaccines, experts say.
Is it normal for the virus to mutate?
Viruses, as living beings, are endowed with genetic material (DNA or RNA), which can be subject to modifications when they replicate (mutations) in the cells in which they spread or through exchanges between viruses (recombinations). In general, this does not usually have consequences, but mutations can also give the virus an advantage or disadvantage for its survival.
There are surely thousands of variants, recalled Emma Hodcroft, an epidemiologist at the University of Bern.
The most important thing is to try to know if this variant has properties with an impact on 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 British government to raise the alarm, carries a mutation, called "N501Y", at the height of the spike protein of the coronavirus
, with which the virus attaches itself to human cells to penetrate them.
Is this variant more contagious?
According to British Prime Minister Boris Johnson
, this strain could be up to 70% more contagious, prompting many European countries and the rest of the world to suspend their air and rail connections with the United Kingdom.
The United Kingdom has faced 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 Sunday the European Center for Disease Prevention and Control (ECDC).
The reasons for this increase in infectivity are still unclear. We still have to find out if it is due to increased viral replication or a better connection with the cells that cover the nose and lungs, Peter Openshaw, professor of experimental medicine at Imperial College London, nevertheless told the Science Media Center.
For her part, Emma Hodcroft was cautious about stating that the virus could be "70% more contagious", because when estimates are made too early they may end up changing. We don't know much where this figure came from, he warned.
In addition, in that region of south-east England, group immunity in the population is weak and the virus found a ground to develop, the deputy director of the National Reference Center for Respiratory Viruses at the Pasteur Institute explained to AFP. Paris, Vincent Enouf.
How did this strain circulate?
It is difficult to say that this new form was born in the United Kingdom, which is the world leader in sequencing. So if there is a variant and it reaches the UK, there is a good chance that it will be detected, said Emma Hodcroft. According to her, the first sequence of that new strain dates back to September.
According to the World Health Organization (WHO), similar forms were detected in several countries, such as Australia (one case), Denmark (9), the Netherlands (1) and South Africa. Italy also announced that it detected a first case on Sunday.
Although it was not born in the UK, it seems that it developed there, said Emma Hodcroft.
Will the vaccine be less effective?
At the moment, scientists see it implausible that this new strain is resistant to current vaccines against Covid
The idea of the vaccine
is to show the whole Spike protein to the immune system, which in this way learns to recognize its many parts, explained Emma Hodcroft. Thus, although some parts change, the rest of the parts remain to recognize the virus, he said.
Vincent Enouf said that a repertoire of antibodies should suffice.
At the moment, there is nothing to indicate that this new strain has a higher mortality rate or that it affects vaccines and treatments, but urgent work is underway to confirm that, added England's chief physician Chris Whitty. WHO and ECDC came to the same conclusion.
Will it affect the tests?
Those responsible for the laboratories should verify with their suppliers if their tests could be defective for this new variant, highlighted Vincent Enouf.
According to the ECDC, the change in the Spike protein caused false negatives in some UK test labs, which rely solely on that protein in their analyzes.