Japan is considering making the elderly and people with underlying medical conditions eligible for fourth coronavirus vaccine shots, in line with recommendations by the ruling Liberal Democratic Party, government sources said Tuesday.

The Ministry of Health, Labor and Welfare will also consider whether to make medical staff eligible for the shots after some experts voiced support for the move, the sources said.


The ministry will finalize the plan after hearing views from experts in a vaccine panel meeting slated for April 27, the sources said.

The move would mark a significant change in the way Japan has handled vaccinations for COVID-19, as the country has so far covered a wide range of age groups for inoculation.

Limiting the eligibility for the fourth shots stemmed from reports the effectiveness of such shots has been low in younger people and similar trends overseas where they have been mainly targeted toward the elderly, according to the sources.

The main purpose of vaccinations is to prevent the development of severe symptoms, for which third doses have shown to be effective in preventing in young people against the Omicron variant.

However, the effectiveness of shots of U.S.-manufactured Moderna and Pfizer vaccines, which are the two mainly used vaccine drugs in Japan, has been found to wane over time, prompting the health ministry to consider administering the fourth inoculations.

The United States, Europe and other countries have continued to proceed with administering fourth shots.

The U.S. Food and Drug Administration advises inoculations for people aged 50 and older, and those who are immunocompromised.

The European Medicines Agency recommends fourth shots for those aged 80 and older, saying it is still too early to consider them for anybody below that age.

Israel commenced administering fourth shots before the Omicron variant became widespread, with studies showing that infection rates were halved in people over 60 years old who received the shots compared with those who only received the third dose.