"BA.5 Movement, 1/12th in Centaurus in Animal Experiments"

[Asia Economy Reporter Hyunseok Yoo] A research team from the University of Tokyo and others announced animal experiment results suggesting that even if immunity is formed after infection with the COVID-19 BA.5 variant, which has become the dominant strain in Korea and Japan, it may be difficult to prevent infection by the BA.2.75 variant (commonly known as Centaurus).

According to a report by NHK on the 14th, the research team, including Professor Kei Sato of the Institute of Medical Science at the University of Tokyo, disclosed these findings in a paper prior to third-party review.

Using blood from hamsters infected with the BA.5 variant, they investigated the activity of neutralizing antibodies that suppress the virus, finding that the neutralizing antibody activity against BA.2.75 was only about one-twelfth of that against BA.5.

Professor Sato stated, "Neutralizing antibodies produced after infection with BA.5 may not be effective against BA.2.75," adding, "As the variant transition progresses, it is possible that current infections will not sufficiently decrease."

To investigate pathogenicity, hamsters were infected with the actual virus, and the research team explained that inflammation in the organs and lung damage indicators for BA.2.75 were almost the same as those for BA.5.

To verify vaccine effectiveness, a virus reproducing the characteristics of BA.2.75 was created, and using blood from individuals who had received three vaccine doses, the movement of neutralizing antibodies obtained from the vaccine was examined, revealing levels comparable to those against BA.2 (Stealth Omicron).