A Japanese health ministry panel approved on Wednesday the administration of third booster shots of U.S. pharmaceutical giant Pfizer Inc.'s COVID-19 vaccine to children aged between 12 and 17.

The ministry will decide Thursday on the details of the rollout, including offering the booster shots free of charge, as with the first two shots, with vaccinations to begin as early as next month.

The ministry's panel last November approved Pfizer booster shots for people age 18 and over, but did not include those aged between 12 and 17 due to a lack of clinical trial data available for the age group at the time.

It decided to lower the age for third shot recipients after studying data from countries such as Israel and the United States, which have already begun giving additional protection to children with boosters.

The data showed that the frequency of side effects was comparable to, or less than, the first two shots, and that there were no major safety concerns.

The third shot also boosted the vaccine's effectiveness that has been found to wane over time following the second shot, according to the data.

The ministry expects a certain degree of effectiveness against the highly contagious Omicron variant of the coronavirus, which was included in the reviewed data.

Pfizer's COVID-19 vaccine was first approved in Japan in February last year for those aged 16 and over, with the rollout subsequently expanded to children aged 12 to 15 in May.

While it remains unknown what percentage of those aged 12 to 17 are fully vaccinated in Japan, government data shows that the double-dose vaccination rate for those between 12 and 19, including Moderna Inc.'s COVID-19 vaccine, stands at around 75 percent.

Currently, individuals aged 18 or older can receive booster shots at least six months after receiving their second dose.

Related coverage:

Japan begins COVID-19 vaccination for children aged 5-11

Japan to buy additional 10 million COVID vaccine shots from Pfizer

Japan to begin COVID booster shots for general public sooner