Japan's health ministry on Monday approved the production and sale of vaccines against the Omicron variant of the coronavirus, with the government to send the shots to local municipalities from Sept. 19.

The additional inoculation, believed to be effective against the BA.5 subvariant of COVID-19 now prevalent in Japan, will initially be targeted toward the elderly and medical workers.

Prime Minister Fumio Kishida has said he plans to expand from mid-October eligibility for the additional shots for everyone over the age of 12 who has received at least two vaccine doses.

The policy is part of wider preparations to provide over 1 million shots per day between October and November to curb the spread of infections during the winter period.

Currently, a booster shot can only be administered a minimum five months after the last vaccine dose. But as a panel of experts suggested that the interval period should be shortened, the health ministry will reach a conclusion by the end of October on whether to cut the time between vaccinations.

The Omicron boosters have properties derived from the BA.1 subvariant, as well as the original strain that spread early in the pandemic.

U.S. pharmaceutical firms Pfizer Inc. and Moderna Inc. had each applied to the Ministry of Health, Labor and Welfare to produce and sell their Omicron vaccines tailored for the highly transmissible variant.

Following the approval, Pzifer will supply 28 million shots to those aged 12 and over, while Moderna will provide 2 million doses for people over the age of 18.

According to health ministry documents, the boosters contain a higher amount of neutralizing antibodies that suppress the movement of the BA.1 subvariant in the body compared with the vaccine for the original virus and are also believed to be effective against BA.5 and other subvariants that could develop in the future.

Japan reported 52,918 new virus cases on Monday, roughly 15,000 fewer than the figure from the week before, reflecting a downtrend in new infections.

The Tokyo metropolitan government reported 5,654 new cases on Monday, while infections in neighboring Kanagawa and Saitama prefectures numbered 4,476 and 3,689, respectively.

New COVID-19 deaths reached 145 nationally.