“English mutant” SARS-CoV-2. What is known and what does it mean?
The last days in the “covidosphere” is dominated by the news about the “English mutant” SARS-CoV-2. Its working designation looks almost cryptic – VUI-202012/01, but the decoding is trivial – “the first“ Variant Under Investigation ”in December 2020. Let me remind you that a mutation is any deviation in the genomic sequence of the isolate under study from the “canonical” genomic sequence of SARS-CoV-2 (the sequence of nucleotides in the genomic RNA of the first “Wuhan” isolate of SARS-CoV-2). In total, since January 2020, thousands of mutations have been discovered (only in protein S there are about 4000 of them). The vast majority of them do not noticeably affect the infectivity (contagiousness) and pathogenicity (virulence) of the virus.
In the genome of the “English mutant” there are 17 differences from the canonical sequence. Almost all of them are likely to be “harmless.” But there is one “suspect” – a mutation in protein S (N501Y; substitution of asparagine for tyrosine at position 501). It is located in the region of protein S (RBD) that is directly involved in binding to the ACE2 receptor. At the same time, epidemiological data show that the mutant variant of the virus is spreading rapidly. The degree of increase in the contagiousness of the VUI-202012/0 variant, according to preliminary estimates, is around 70%. The VUI-202012/01 variant was first discovered in September and now it accounts for about 20% of the isolates whose genomic sequence has been determined in the “epicenter” (Norfolk County).
The proportion of the mutant variant is growing rapidly in other regions of England. However, where VUI-202012/01 is the most common variant, there is no spike in severe cases and deaths. If this is true, then the virulence of the VUI-202012/01 variant is not increased. However, many countries, including Russia, have stopped or are suspending flights to Britain.Поділитися цим: