New offspring of Ba.2 subvariant detected in Japan

TOKYO (Jiji Press) — A new offspring of the Ba.2 subvariant of the omicron coronavirus has been discovered for the first time in Japan, Tokyo Medical and Dental University said Monday.

It is one type of the widely circulating Ba.2 subvariant, but it has a mutation in the spike protein seen in the delta variant, according to the university. Spike proteins are used by the virus to invade cells.

The offshoot was detected in mid-April from two in-patients at the university hospital. They had no record of traveling abroad and are believed to have caught the virus through community transmission.

The offspring of the Ba.2 subvariant was discovered by analyzing the entire genome of in-patients.

Both patients had mild symptoms, and they had been vaccinated with booster shots.

“The offshoot could possibly be more transmissible than Ba.2. If it gains a foothold, infection cases may remain elevated for a long time,” said Hiroaki Takeuchi, associate professor at the university.