China CDC： There is little difference among the five branches of mutation acceleration in Covid-19.

　　On the afternoon of September 8th, the State Council Joint Prevention and Control Mechanism held a press conference to introduce the situation of scientific and accurate epidemic prevention and control, and to answer media questions.

　　Dong Xiaoping, chief expert of virology of China CDC, said that new branches of virus variation and evolution are constantly emerging around the world, such as BF.15, BA.5.2 and BA.5.2.3 of Omicron mutant. The variation of RNA virus genome is a very common natural phenomenon, and there will be some variations in the process of virus infection and replication, which are often random. Covid-19 belongs to RNA virus, and its genome consists of nearly 30,000 nucleotides. It is natural that one to several nucleotides may mutate during each replication. On the other hand, the global large-scale vaccine use in a short time and the immune barrier formed by a large number of naturally infected people will also accelerate the mutation of Covid-19.

　　Since Omicron mutant appeared in November last year, it has formed five big evolutionary branches, from BA.1 to BA.5, which still belong to Omicron mutant. From the whole observation, it is true that there are some differences in transmission ability, pathogenicity and immune escape ability among branches, but there is little difference on the whole.

　　For Covid-19’s mutation, we pay more attention to the influence on transmission ability, pathogenicity and immune escape ability. At the same time, not every so-called evolutionary branch or mutation will obviously affect the changes of the above three abilities. Therefore, timely monitoring of virus mutation is very critical and important for timely adjusting prevention and control strategies and developing drugs and vaccines.