[Details] Is there any concern about an increase in "BA.2.75", a type of Omicron strain?

"BA.2.75" (BA.2.75), a type of Omicron strain of the new coronavirus, is increasing mainly in India.

In many parts of the world, the Omicron strain "BA.5", which has almost replaced in Japan, is the mainstream, and it is not clear whether the infectivity of "BA.2.75" or whether it is likely to become severe if infected, but it is a specialty. The house says, "Even in Japan, there is concern that it may increase after the current epidemic has subsided."

"BA.2.75" is a mutant virus of the "BA.2" strain of the Omicron strain, which was the main infection in Japan until June.

According to the WHO = World Health Organization, it was first reported in India in May, and according to the ECDC = European Centers for Disease Control and Prevention report on the 23rd of this month, it is now found in 21 countries.

It has been confirmed in Japan as well in Tokyo and Kobe.

According to the National Institute of Infectious Diseases, there are several mutations in the spike protein compared to "BA.2". Among them, for example, the mutation "G446S" is common to the Omicron strain "BA.1". It means that there is a possibility of escaping the neutralizing antibody obtained by vaccination.

In India, the number of infected people and the number of deaths remained at a low level as of May, but since then it has turned to an increasing trend, and it is possible that the expansion of "BA.2.75" has had an effect. Sex is also pointed out.

However, in many regions other than India, "BA.5", which has accounted for almost all of Japan, continues to be the mainstream.

ECDC positions "BA.2.75" as a "variant of concern = VOI", but in a report on the 15th of this month, it is said that the infectivity, the effect on immunity, and the severity of infection are not yet known. is.

The research group "G2P-Japan", which is presided over by Professor Kei Sato of the Institute of Medical Science, the University of Tokyo, artificially creates a virus that reproduces the spike protein, which is the protruding part on the surface of "BA.2.75", and is a therapeutic drug. I investigated whether the ingredients of were effective.

According to the results of experiments using cells published on the Internet as a paper before being reviewed, among the antibody drugs that are administered by instillation to people at risk of aggravation among the therapeutic drugs approved in Japan, ▼ "Sotrovimab" While the component suppressed the action of the virus, the component of "Ronapreve", an antibody cocktail therapy in which two types of antibodies are administered by instillation at the same time, could not suppress the action of the virus.

Professor Hiroshi Nishiura, Kyoto University "It may be easy to spread"

In India, the number of infected people and the number of deaths remained at a low level as of May, but since then it has turned to an increasing trend and it is possible that the expansion of "BA.2.75" has had an effect. Has also been pointed out.

Professor Hiroshi Nishiura of Kyoto University said at a meeting after the expert meeting of the Ministry of Health, Labor and Welfare on the 27th, "BA.2.75" was "not fully analyzed due to the limited endemic area, but when looking at the infection situation in India It may be easier to spread than before. "

A screening test in Tokyo confirmed that two people were infected with "BA.2.75" for the first time on the 21st, but Professor Nishiura may have already had more than a dozen infected people in Tokyo at this time. After showing an estimate that there is, regarding the impact of further increase in "BA.2.75" in the future, "The 7th wave will rise again after peaking, or the epidemic will be prolonged and medical care will be tight. It is expected that it will happen. "

The idea is that it will be necessary to establish a system that can correctly grasp the status of infection in case "BA.2.75" spreads in Japan, and then disseminate information on the risk of aggravation and the effects of vaccines to the world. Was shown.

Tokyo Medical University Atsuro Hamada Specially Appointed Professor "Possibility of strong infectivity"

Atsuo Hamada, a specially appointed professor at Tokyo Medical University, who is familiar with overseas infectious diseases, also said, "The actual situation of" BA.2.75 "has not been fully clarified yet, but the infectious power has been" BA.2 "and" BA.5 ". There is a certain possibility that it will be stronger than the current "BA.5" epidemic in Japan, and there is concern that it will increase after the current "BA.5" epidemic has subsided. "

On the other hand, on Twitter etc., the upper body is a person, the lower body is a horse monster, and it is called "Centaur". "BA.2.75 is" BA.2 "and" BA.5 ". It seems that it is called like this because it has both characteristics, but it is not an officially decided name. "