Pfizer asks Japan's health ministry to approve bivalent COVID vaccine

US drug maker Pfizer has asked Japan's health ministry to approve the use of its coronavirus vaccine that it says is effective against the BA.5 subvariant prevailing now in Japan.

The firm announced that it filed the request on Tuesday for the bivalent vaccine that targets the Omicron subvariants BA.4 and BA.5, as well as earlier strains.

Such messenger RNA-based vaccines enable the human body to create spike proteins and build up an immune response. The spike proteins of the BA.4 and BA.5 subvariants are identical.

Pfizer said pre-clinical data show that a booster dose of the vaccine generated a strong neutralizing antibody response against the Omicron subvariants, as well as the original virus.

In the United States, the FDA granted authorization on August 31 for emergency use of the updated Pfizer vaccine as an additional inoculation for people aged 12 or older.

On the day after, the US Centers for Disease Control and Prevention announced that it recommends the use of the vaccine.