Regarding "BA.5", which is a type of Omicron strain of the new coronavirus and is being replaced, groups such as the University of Tokyo say that the ability to cause symptoms may be higher than that of the previous Omicron strains. We announced the results of experiments with animals.
This research was published on the Internet as a paper before being officially peer-reviewed by the group "G2P-Japan" led by Professor Yoshi Sato of the Institute of Medical Science, the University of Tokyo.
The group created a virus that reproduced the characteristics of "BA.2" and "BA.5" of the Omicron strain, infected cultured cells, and investigated how they increased. After 24 hours, "BA.5" The virus in was 34 times more than that of "BA.2".
Furthermore, in an experiment to infect hamsters, "BA.2" did not lose weight, whereas "BA.5" lost about 10%, indicating that inflammation of the lungs and other parts was intensifying in addition to body weight. is.
The group said that it is necessary to investigate the symptoms in humans, and that "BA.5" may have a higher ability to cause disease than "BA.2" of the same Omicron strain. It is said that.
Professor Sato said, "The virulence of the virus does not necessarily weaken. The virus will continue to change, so caution is required."