The British government said Tuesday to "monitor very closely" a new subvariant of Covid-19.
It is spreading in the United Kingdom, which is facing an increase in contamination, without it being established as is whether this sub-variant is more contagious.
This variant called “AY4.2” is a sub-variant of the highly contagious Delta which initially appeared in India and which caused a resumption of the epidemic in late spring and early summer.
"We are monitoring" this new form very closely "and we will not hesitate to take action if necessary," said a spokesman for Downing Street, the seat of government.
However, "nothing suggests that it spreads more easily", he tried to reassure.
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The emergence of this new variant despite the very strong contagiousness of the Delta, which tends to rule out new strains, raises fears of an even stronger transmissibility.
It comes as the United Kingdom, which deplores nearly 139,000 deaths from Covid-19, is faced with a growing number of positive cases, now exceeding the 40,000 mark every day, an incidence rate much higher higher than in the rest of Europe.
It would not be at the origin of the sharp rise in cases
Some scientists attribute the current degradation, which for the moment mainly concerns adolescents and young adults, to the weak vaccination of minors, to the decrease in the immunity of the oldest vaccinated very early, or to the lifting, in July , in England, most of the restrictions such as indoor masks.
But, for François Balloux, director of the Institute of Genetics at UCL (University College London), the new variant "is not at the origin of the recent increase in the number of cases in the United Kingdom".
He explains that with its low frequency so far, even "a 10% higher transmissibility could only have caused a small number of additional cases".
The emergence of AY4.2 does not constitute "a situation comparable to the emergence of the Alpha and Delta strains which were much more transmissible (50% or more) than all the strains in circulation at the time", added the researcher. .
The new variant AY4.2 is almost non-existent outside of the UK, apart from three cases in the US and a few more in Denmark, which have since almost disappeared.
Work is underway to test its resistance to vaccines.