Researchers say multiple COVID-19 drugs that have been approved in Japan show efficacy against the Omicron BA.2.75 subvariant.

Kawaoka Yoshihiro, a project professor at the University of Tokyo's Institute of Medical Science, and 13 other Japanese and US scientists published their findings in the New England Journal of Medicine.

They say the antiviral agents remdesivir, molnupiravir and nirmatrelvir may be effective against BA.2.75, which has been detected in dozens of countries including the United States, Britain and Japan.

The virus-neutralizing antibodies casirivimab-imdevimab and sotrovimab were found to be significantly less effective against the variant.
But the researchers do say that tixagevimab-cilgavimab, approved last month, did show neutralizing activity.

The researchers say BA.2.75 is spreading rapidly in India and Nepal. The World Health Organization has designated it as a subvariant under monitoring.

The Omicron subvariant BA.5 is driving Japan's current wave of infections. Professor Kawaoka says available treatments are sufficient to cope with a possible surge of BA.2.75.