He is watched like milk on fire. a new subvariant of the coronavirus is currently spreading in the United Kingdom, facing an increase in Covid-19 contaminations. 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 watching very closely” this new shape “and we will not hesitate to take action, if necessary”, a Downing Street spokesperson said. Here is what we know and what we do not yet know about this new strain.
What we know
It has been identified in four countries. The new variant AY4.2 is mainly present in the United Kingdom. Seven cases have also been identified in the United States, according to The San Francisco Chronicle*, which refers to Outbreak.info *, the American site that tracks Sars-CoV-2 variants and sub-variants. According to AFP, a few other cases have been sequenced in Denmark, which have since almost disappeared. A case has just been spotted in Israel, the health ministry announced on Wednesday (October 20). This is an 11-year-old child who arrived from Europe at Ben-Gurion Airport in Tel Aviv. He was quarantined, said the same source, stressing that no other case has since been identified. For the moment, the AY4.2 has not been officially listed in France.
It affects almost 8% of new cases in the UK. The AY4.2 is “on an increasing trajectory” in the United Kingdom, recognizes the British Health Safety Agency. In the week of September 27, it accounted for 6% of new cases, according to an agency report *. According to Dr. Scott Gottlieb, former commissioner of the Food and Drug Administration (the US health agency), it now represents 8% of cases. That is 14,705 sequences, precise The San Francisco Chronicle.
UK reported its biggest one-day Covid case increase in 3 months just as the new delta variant AY.4 with the S: Y145H mutation in the spike reaches 8% of UK sequenced cases. We need urgent research to figure out if this delta plus is more transmissible, has partial immune evasion?
– Scott Gottlieb, MD (@ScottGottliebMD) October 17, 2021
He is one of the 56 sublines of the Delta variant. AY4.2 is a branch of AY.4, which is itself a branch of the “mother” Delta variant. When the virus makes copies of itself, small errors occur that lead to slight variations, which result in sublinelines. According to Outbreak.info, the Delta variant now has 56 sublines. As the British health agency specifies in its report, AY4.2 contains two major mutations, A222V and Y145H, in the spike protein, which allows the virus to enter cells.
It is starting to be researched. Although it is not yet classified as a ‘variant of concern’ in the UK, work is underway to test its resistance to vaccines. In Israel, the Prime Minister asked to strengthen the epidemiological investigation on this new variant and to contact the countries where he is present to exchange information and consider changes to the instructions for entering tourists into the territory. In his tweet, Scott Gottlieb calls for a “urgent research” on this branch of the Delta.
What we don’t know yet
If it is more contagious and more dangerous than the other variants. 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 greater transmissibility. Corn “nothing suggests that it spreads more easily”, tried to reassure a spokesperson for Downing Street. For François Balloux, director of the Institute of Genetics at UCL (London), the AY4.2 “is not the cause of the recent increase in the number of cases in the UK”, which has more than 40,000 new contaminations per day.
According to him, with its low frequency so far, even “10% higher transmissibility could have caused only a small number of additional cases”. For the researcher, the situation is currently not “comparable to the emergence of the Alpha and Delta strains which were much more transmissible (50% or more) than any strains in circulation at the time”. It is also too early to know if it is more dangerous.
If it thwarts immunity from vaccines. The progression of AY4.2 in the UK, however, highlights a phenomenon that scientists have warned against throughout the pandemic: the rampant transmission of the virus can create new, more resistant variants. As an American scientist, David States, points out, on Twitter*, the rapid increase in the prevalence of this Delta subvariant suggests that it would be able to resist some immunity, with a large part of the British population now being fully vaccinated (nearly 80%) or having already had Covid-19.
“We don’t know if Delta AY4.2 escapes vaccine-induced immunity or, if so, which vaccines are most effective against it. We also don’t know if it is more. likely to cause serious infections. Like I said, we don’t know much “, admits the doctor, suggesting to keep a close eye on this umpteenth mutation.
* Links followed by an asterisk open content in English.