Research results show that the derivative strain of Omicron strain 'BA.2' has both the aggravation rate of Delta strain and the infectivity and anti-vaccine property of Omicron strain.



A research team led by Associate Professor Yoshi Sato of the Institute of Medical Science, the University of Tokyo, has announced the results of research on a further derivative of the omicron variant of the new coronavirus (SARS-CoV-2), ' BA.2 '. According to Sato et al., BA.2 has both the aggravation rate of the Delta strain and the anti-vaccine property of the Omicron strain.

Virological characteristics of SARS-CoV-2 BA.2 variant | bioRxiv
https://www.biorxiv.org/content/10.1101/2022.02.14.480335v1

Coronavirus: As BA.2 subvariant of Omicron rises, lab studies point to signs of severity --CNN
https://edition.cnn.com/2022/02/17/health/ba-2-covid-severity/index.html

'BA.2', which was the subject of this research, is a mutant strain that seems to be derived from the Omicron strain 'BA.1'. Regarding BA.2, which is also called 'stealth omicron' because it is difficult to identify by inspection, Mr. Sato et al. 'Show a severity rate equivalent to the delta strain, which is stronger than the omicron strain.' 'Avoid the immune response' was clarified.

The following is a tweet that Mr. Sato himself explains about the outline of the paper published by Mr. Sato et al. The point found by this study is that the infectivity of BA.2 is equivalent to '1.4 times that of BA.1', and that the mainstream of infection is already being replaced by BA.2 in Denmark, India, and the Philippines. According to media reports, BA.2 is actually dominant in at least 10 countries such as Bangladesh, Brunei, China, Denmark, Guam, India, Montenegro, Nepal, Pakistan and the Philippines, of which the hospitalization rate and hospitalization rate and It is said that an increase in the mortality rate has been confirmed.




In addition to the above, as a result of a neutralization test using the serum of the vaccinated person, BA.2 is extremely resistant to the neutralizing antibody induced by the vaccine and is effective against the Omicron strain. It is resistant to the new coronavirus infection drug ' sotrovimab '.




According to experiments using hamsters and mice, the immunity acquired with BA.1 is difficult to work against BA.2.




The artificially synthesized 'new coronavirus with peaplomer of BA.2' shows higher pathogenicity than BA.1 in experiments using hamsters, and its intracellular growth rate is also high. I understand.




From the above points, Mr. Sato stated that 'BA.2 (stealth omicron) has a higher risk than BA.1 (conventional omicron) in terms of transmission power, pathogenicity, and immune resistance.' , Insists that we should be wary of BA.2, which is becoming more widespread in Japan.




This paper is in a 'preprint' state that has not yet been peer-reviewed. 'There is no evidence that the BA.2 strain is more serious than the BA.1 strain. CDC is prevalent at home and abroad,' said Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC), which leads the control of infectious diseases in the United States. We continue to monitor the variants that we are doing. '

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in Science, Posted by darkhorse_log