Okayama Prefecture announced that a new mutant virus called "BA.4", which is one of the strains of the Omicron strain of the new coronavirus, has been confirmed in the prefecture.

This is the first time that "BA.4" has been confirmed in Japan except for quarantine.

According to Okayama Prefecture, a detailed examination of a sample collected from one person who was confirmed to be infected with the new coronavirus in the prefecture this month confirmed that it was a new mutant virus called "BA.4".

"BA.4" is the first mutant virus detected in South Africa in January, and according to the prefecture, it is the first virus to be confirmed in Japan except for airport quarantine.

It was also found that a mutant virus called "BA.5", also found in South Africa, was confirmed by another infected person for the first time in Okayama prefecture.

The prefecture does not disclose the age and gender of the two, but since they both had symptoms after returning from overseas, they did not see it as a community-acquired infection, and both of them had mild symptoms. ..

Okayama Prefecture said, "At present, there is scientific evidence that the National Institute of Infectious Diseases has a large difference in the rate of aggravation compared to the conventional Omicron strains in both" BA.4 "and" BA.5 ". It is not the case, "he said, and it is necessary to continue to pay close attention to the spread and symptoms of the infection.