COVID-19 XE variant has some experts worried it will spread to Japan

By: 3 years ago

Japan's Kyoto, Fukuoka prefectures find new Omicron cases

FILE PHOTO: Commuters wearing protective face masks are seen a day after the government announced the lifting of the state of emergency by the coronavirus disease (COVID-19) in large parts of the country including Fukuoka, in Fukuoka, southern Japan, in this photo taken by Kyodo May 15, 2020. Mandatory credit Kyodo/via REUTERS

TOKYO — A novel coronavirus variant known as XE, which is believed to be more contagious than previous variants, has been detected in the United Kingdom among other countries, and there are concerns it might spread to Japan.

According to the World Health Organization, the XE variant is a recombinant of the Omicron subvariants prevalent in Japan: BA.1 from the sixth wave and BA.2, which is predominant in current infections. It was first detected in the United Kingdom on Jan. 19 this year, with about 600 confirmed cases of XE as of March 29.

XE appears to have arisen after genetic recombination of the virus in a person who was infected with both Omircon subvariants at the same time.

The new variant is said to be 10% more infectious than BA.2. Vaccine efficacy and the detailed nature of XE is not yet known, so further confirmation is needed, the WHO said.

“We don’t know the relation of the new variant to more serious symptoms,” Takaji Wakita, director general of the National Institute of Infectious Diseases and chair of a health ministry advisory panel, said April 6. “We need to keep conducting genomic analysis at quarantine.”

Hiroshi Nishiura, a professor of theoretical epidemiology at Kyoto University, said “There is a high probability this variant will replace the Omicron variant when cross-border traffic becomes more active.”

In Europe, more than 80 cases have been detected of the XD variant dubbed “deltacron” — a recombinant of the delta variant from the fifth wave in Japan and the Omicron BA.1 subvariant. The exact nature of XD is also unknown.

While neither deltacron nor XE have been detected in Japan, Tetsuya Mizutani, a professor of virology at Tokyo University of Agriculture and Technology said, “Japan should have a surveillance system in place to contain the spread from overseas quickly.”