Japan has begun administering the third dose of coronavirus vaccine across the nation, initially targeting healthcare workers, according to NHK World-Japan.

A vaccination site was set up before 9 a.m. on Wednesday, at the Tokyo Medical Center in Meguro Ward. A total of 18 doctors and nurses received a booster jab of the Pfizer vaccine after presenting health-check sheets.

The medical center head Araki Kazuhiro said he is relieved to see the first crucial step taken toward the goal of ensuring the safety of all patients and their families as well as hospital staff.

He said the effectiveness of existing coronavirus vaccines against the Omicron variant is still uncertain. However, he said that the vaccines have proven to be effective against the Delta and other variants to a certain extent and the rollout of the third shots is very important.

The health ministry says 1.04 million healthcare workers who received their second shot at least 8 months ago are eligible for a booster shot in December, in principle.

An additional 2 million healthcare professionals and 1.03 million people, including those aged 65 or older, will be eligible in January next year. In March, so-called workplace inoculations are scheduled to begin at companies and universities.

Vaccination tickets for booster shots are expected to be delivered by post before the passage of 8 months from one's second dose.

Officials say even if their delivery is delayed, arrangements will be made so people can receive a booster shot as an exception.