Japan's health ministry on Wednesday granted special fast-track approval to U.S. pharmaceutical giant Pfizer Inc.'s updated coronavirus vaccine tailored to protect against the now-prevalent BA.5 subvariant.

The ministry also approved the administration of Pfizer's coronavirus vaccine targeting the original strain to children aged between 6 months and 4 years old, making it the first COVID-19 vaccine available in Japan for the age group.

Pfizer applied in September for approval of its bivalent vaccine, which works against the Omicron subvariants BA.4 and BA.5 and earlier strains. The Japan unit of Moderna Inc. said Wednesday it has requested that the ministry green light a similar vaccine.

Both companies' updated vaccines have already been rolled out in the United States after receiving emergency use authorization.

To stem the ongoing seventh wave of COVID-19 infections powered mostly by the BA.5 subvariant, Japan started giving Omicron booster shots made by Moderna and Pfizer in September, but they are tailored to the BA.1 subvariant.

Pfizer's vaccine for children aged 6 months to 4 years targets the original strain of the virus that emerged in late 2019 in the Chinese city of Wuhan, with the United States granting it, along with Moderna's vaccine, approval for emergency use in June.

Related coverage:

Japan gov't selects 17 projects to support vaccine manufacturing

Japan begins giving Omicron booster shots to stem 7th COVID wave

Takeda apparently to become 1st Japan's firm to sell vaccine abroad