Scientists are anxiously following a descendant of the Delta strain of coronavirus, which is responsible for a growing proportion of Covid-19 cases in the UK, which could be more infectious than the original Delta variant, writes the Financial Times.
This subvariant AY.4.2 has only recently been observed by virologists following the genetic evolution of Delta, but already accounts for almost 10% of cases in the United Kingdom.
Its prevalence is growing rapidly, but not as fast as that of the original Delta variant that arrived in India this year from India.
Two experts – Jeffrey Barrett, director of the Genomics Initiative at the Wellcome Sanger Institute in Cambridge, and Francois Balloux, director of the University College London Genetics Institute – say that AY.4.2 appears to be 10-15% more transmissible than the original Delta strain.
AY.4.2, probably the most contagious coronavirus variant
If these preliminary findings are confirmed, AY.4.2 could be the most infectious strain since the beginning of the pandemic, Balloux said.
“But we must be careful at this time. The United Kingdom is the only country in which it ‘took off’ in this way and I would not exclude the hypothesis that this increase was caused by a random demographic event “, the researcher specified.
“AY.4.2 will probably be elevated to the rank of ‘variant under investigation,'” Balloux added, meaning that at that time it will be named after a Greek letter.
Some experts in the United States have said that there is a link between the occurrence of AY.4.2 and the very high level of Covid-19 cases and deaths in the UK, far above those in the rest of Western Europe.
On Monday, the United Kingdom announced 49,156 positive tests, the highest balance since July. The average of the last 7 days is 16% higher than in the previous week.
The subvariant has two mutations in the Spike protein
Scott Gottlieb, a former commissioner in the US FDA, said that “we need urgent studies to see if this ‘Delta plus’ is more transmissible[orcanpartiallyavoidimmunity”[saupoateevitaparțialimunitatea”
British experts say research is already underway. “Although (AY.4.2) may complicate the situation, it may not be the only explanation for the recent increase in the number of cases in the UK,” Barrett said.
The use of the phrase “Deta plus” has caused a lot of confusion and should be avoided, he added. The term has already been used by some analysts to refer to other, previous, descendants of Delta, other than AY4.2.
This is one of the 54 sub-variants of Delta that have been recorded in the world. AY.4.2 has two characteristic mutations in the spike protein with which the coronavirus infects human cells, mutations entitled Y145H and A222V.
Both mutations have been seen before in other coronavirus strains, but not in “worrying variants,” Balloux said, and it’s unclear why it could make Delta more infectious.