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
Coronavirus: As BA.2 subvariant of Omicron rises, lab studies point to signs of severity --CNN
'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.
The following is an outline of this research.— The Sato Lab (Kei Sato) (@SystemsVirology) February 16, 2022
1 ⃣ Mathematical statistical analysis of virus sequences revealed that the #transmitting power of BA.2 (stealth omicron) is about 1.4 times higher than that of BA.1 (conventional omicron). In fact, countries such as Denmark, India and the Philippines are already replacing BA.2. 2/6 pic.twitter.com/qt2OfaHLBW
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 '.
2 ⃣ As a result of the neutralization test using the serum of the vaccinated person, BA.2 (stealth omicron) is extremely resistant to the neutralizing antibody induced by the vaccine like BA.1 (conventional omicron). Revealed. 3/6 pic.twitter.com/Y7ZYvzf3yl— The Sato Lab (Kei Sato) (@SystemsVirology) February 16, 2022
According to experiments using hamsters and mice, the immunity acquired with BA.1 is difficult to work against BA.2.
3 ⃣ As a result of a neutralization test using serum of hamsters infected with BA.1 and recovered, or mice immunized with the spike protein of BA.1, the immunity acquired by BA.1 was against BA.2. It was revealed that it was difficult to work (the serum of the experimental animal was used because the serum of the unvaccinated BA.1 infected recovery person was insufficiently collected). 4/6 pic.twitter.com/UzbRpFzREk— The Sato Lab (Kei Sato) (@SystemsVirology) February 16, 2022
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.
4 ⃣ Since the clinical isolate of BA.2 had not been obtained yet, we artificially synthesized a new coronavirus 'BA.2 S' having a spike protein of BA.2 and conducted an infection experiment using a hamster. As a result, it was clarified that the pathogenicity of 'BA.2 S' is higher than that of BA.1 and equivalent to that of the conventional strain ('B.1.1' in the figure). 5/6 pic.twitter.com/cUuLDqRKWX— The Sato Lab (Kei Sato) (@SystemsVirology) February 16, 2022
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.
Summary ▶ ️ BA.2 (Stealth Omicron) may be at higher risk than BA.1 (Traditional Omicron) in terms of transmission, pathogenicity and immune resistance. BA.2 has already flowed into Japan. The trend of the epidemic depends on future measures, but I think we should be wary of the emergence of high-risk mutant strains. 6/6— The Sato Lab (Kei Sato) (@SystemsVirology) February 16, 2022
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. '
in Science, Posted by darkhorse_log