Japan will begin shipping 4.12 million COVID-19 vaccine doses for third shots to municipalities and medical facilities across the country on Monday.
The health ministry will start giving the shots to medical workers in December, followed by senior citizens in January.
The ministry has decided to give booster shots to all people aged 18 or above who want one, if they received their second dose at least eight months before.
Delivery of Pfizer's vaccine, which was approved for booster shots on Thursday, is expected to take two weeks to complete.
The number of doses allocated to each prefecture is proportionate to the number of people who had received their second shots as of end of May.
The ministry is planning to have a panel of experts evaluate the efficacy and safety of using a combination of Moderna and Pfizer vaccines, as some other countries have done.
Authorities aim to decide whether to approve Moderna's vaccine for booster shots by the end of the year. They would start giving it at workplaces, including companies and universities, from March next year.