Japan is set to begin administering booster shots of COVID-19 vaccine from Dec. 1 after a health ministry panel approved the move on Monday, joining other countries in taking steps to prevent protection from waning over time.

The vaccine developed by Pfizer Inc. and BioNTech SE will initially be the only one used for the third doses, meaning individuals who have received either of the other two types used in Japan -- Moderna Inc. and AstraZeneca Plc. -- will need to "mix and match."

The Ministry of Health, Labor and Welfare panel also said individuals will in principle need to wait eight months between their second and third shots, though local governments can shorten the interval to six months if they deem it necessary, for example to curb an ongoing surge in infections.

Booster shots have proven effective in preventing the decline of protection against infection and severe symptoms over time, with the United States offering them since late September.

Prime Minister Fumio Kishida had vowed to begin administering third doses within the year, with the program set to start with medical personnel before expanding to the elderly in January.

Individuals aged 18 and older will be eligible for the booster shots and those with preexisting conditions or working in high-risk professions will be especially encouraged to get them.

Local governments will begin mailing out vouchers for the booster shots later this month.

Only messenger RNA vaccines developed by Pfizer or Moderna will be administered, regardless of the type individuals received as first and second doses. Moderna's vaccine, however, has yet to be approved by the health ministry for third shots.

The AstraZeneca vaccine, which uses different technology, will undergo further analysis before being used as a booster shot.

According to the Japanese government, more than 75 percent of the country's population has been fully vaccinated, a higher rate than most of the other members of the Group of Seven nations, despite the country getting off to a slow start. More than 78 percent have received at least one shot.

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