Variants with the N501Y mutation are now estimated to be responsible for over 90 pct of new cases of novel coronavirus infection in Japan, it has been reported to a meeting of a health ministry advisory panel.
The estimate, presented on Wednesday, was compiled by the National Institute of Infectious Diseases. The N501Y variants, including one originating from Britain, are more contagious than the original strain and may be 1.4 times more likely to cause severe COVID-19 symptoms, according to experts.
The NIID has found 70 domestic cases of infection with the coronavirus variant spreading widely in India. The Indian variant will be put under stricter monitoring as a mutant strain requiring caution.