London ‘watching closely’ Delta sub variant, AY4.2

This variant, AY4.2, raises concerns that the transmissibility is greater than that of delta. Virtually not found outside the UK, three cases of AY4.2 have been identified in the US and a few more in Denmark, which have almost disappeared since then.

The British government, which is facing an increase in the spread of the Covid-19 virus, said on Tuesday it was “closely watching” a new subtype spreading in the UK, without it being established as if it was more contagious.

This variant AY4.2 is a sub-variable of the highly contagious delta that appeared initially in India and which caused the resumption of the epidemic in late spring and early summer.

A Downing Street spokesperson said: “We are monitoring this ‘new format’ closely and would not hesitate to take action if needed. However, ‘nothing suggests it is spreading more easily’,” he tried to reassure.

Over 40,000 positive cases per day in the UK

The emergence of this new variant despite the very strong infection of Delta, which tends to exclude new strains, raises concerns about the possibility of greater transmission. It comes as the UK, denouncing nearly 139,000 deaths from Covid-19, faces a growing number of positive cases, now exceeding 40,000 each day, an incidence rate much higher than the rest of Europe.

Some scholars attribute the current deterioration, which at present concerns mainly adolescents and young adults, to poor vaccination for minors, lower immunization of older adults too early, or to its lifting in July in England. Restrictions such as inner masks.

“There is no similar case for the emergence of alpha and delta strains”

But for François Ballou, director of the Institute of Genetics at the University of California, the new variant “is not the origin of the recent increase in the number of cases in the UK”. With its low frequency thus far, she explained, “even a 10% higher rate of transmission can only cause a small number of additional cases.”

The researcher added that the emergence of AY4.2 does not constitute a “situation similar to the emergence of alpha and delta strains which were more transmissible (50% or more) than all strains circulating at that time”.

The new variant AY4.2 is almost nonexistent outside the UK, except for three cases in the US and a few in Denmark, which have almost disappeared since then. Work is underway to test its resistance to vaccines.