Mar 13 (NHK) - A group of researchers says a laboratory test shows that three anti-viral drugs for COVID-19 treatment are effective against the BA.2 Omicron subvariant.
The BA.2 subvariant is said to be more transmissible than the original Omicron variant, and has been spreading in Japan and other countries.
The group led by Kawaoka Yoshihiro, project professor at the University of Tokyo's Institute of Medical Science, published its findings in the New England Journal of Medicine.
The researchers used a number of drugs on cultured monkey cells infected with the BA.2 subvariant.
They confirmed that the drugs molnupiravir, nirmatrelvir and remdesivir were effective against the subvariant. But they said they had to increase the concentration of the drugs about three times to achieve the same level of effectiveness they had with an early strain.
The researchers also found that two other drugs approved as COVID-19 treatments in Japan were effective to a certain extent, but their efficacy dropped to around one-fiftieth to one-sixtieth compared to other strains.
The group says it will further examine the efficacy of drugs through animal experiments and other means.
Professor Kawaoka said it is important to establish a system to facilitate access to the three antivirals, as their effectiveness has been demonstrated.
