“AY.4.2.”: British government observes new Delta sub-variant

Coronavirus
“AY.4.2.”: British government observes new Delta sub-variant

Viruses are constantly mutating – this is nothing new. A mutation doesn’t necessarily have to make a virus more dangerous or contagious. However, certain virus variants require special observation. They are classified by the WHO as “Variants of Interest” (VOI) – as variants of particular interest. This is the case, for example, when there are initial indications that the variant could prevail over previous variants because it is more contagious, for example. If this suspicion is confirmed, the mutant is classified as a “Variant of Concern” (VOC), a worrying variant. The WHO currently lists four “VOC”: Alpha, Beta, Gamma and Delta. Some of them combine other questionable virus properties.

The British government is now “very closely” observing a new subspecies of the Delta variant, a spokesman for Prime Minister Boris Johnson said on Tuesday. It is the variant “AY.4.2.”. However, it is still unclear whether the variant will spread faster, emphasized the spokesman. Also became the mutant not yet from the WHO classified as “VOI” or “VOC”. In Great Britain, the previous delta corona variant still dominates.

“AY.4.2.” found in six percent of the samples examined

“AY.4.2.” was detected for the first time in July 2021, according to the “BBC”. Since then, the number of cases with this variant in the UK has increased slightly. According to the British health authorities, the variant made up an estimated six percent of all sequencing investigations at the end of September. The increase could indicate that the new delta subspecies is even more contagious than the previous delta variant, which is already considered highly contagious. Exact investigations on this question are still pending.

“AY.4.2.” possesses two characteristic mutations in the spike protein, Y145H and A222V, which had previously also been observed in some other corona variants. Outside the UK, “AY.4.2.” so far only sporadically proven. A total of three cases have been reported in the United States. The variant also appeared in Denmark and at times made up around two percent of the samples examined. Since then, however, the number of reported cases has been falling again.

An infection with the delta subspecies “AY.4.2.” was recently also detected in Israel. An eleven-year-old boy was quarantined immediately after arriving from Europe.

Expert: Situation not comparable to emergence of Alpha or Delta

In Great Britain, the number of corona cases is currently increasing sharply. Francois Balloux, Director of the “UCL Genetics Institute” at University College London, sees “AY.4.2.” but not the reason for this development. So far, “AY.4.2.” The scientist told the Science Media Center that it has only rarely been proven. Even if you have a ten percent higher transfer rate for “AY.4.2.” suppose, the variant would only be responsible for a small number of additional cases. “The variant has therefore not driven the recent surge in the number of cases in the UK,” said Balloux. He also does not see the two mutations in the virus’ spike protein as “obvious candidates” for an immune escape of the virus. In his opinion, the current vaccines should also work against this mutant.

Most recently, the British authorities had reported more than 40,000 new infections per day. Scientists cite a low vaccination rate among adolescents and declining vaccination protection among the elderly as reasons.

Balloux pointed out that the current situation could not be compared with the emergence of the alpha and later the delta variant – variants that had higher transfer rates of 50 percent or more compared to previous variants. With “AY.4.2.” one may be dealing with a slight increase in transferability, but this would have “no comparable effects” on the course of the pandemic, said Balloux.

It is good that the spread of the virus variant and its properties are being investigated further, the expert told the “BBC”. At the same time, he warned of premature concerns: “At this point in time, I would say you have to wait and see – don’t panic.”

Source: BBC / Science Media Center / with material from AFP

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