US Health Secretary Robert F Kennedy Jr, a vaccine sceptic, has removed all 17 members of a committee that issues official government recommendations on immunisations.
Announcing the move in an editorial in the Wall Street Journal, Kennedy said that conflicts of interest on the Advisory Committee on Immunization Practices (Acip) were responsible for undermining trust in vaccinations.
Kennedy said he wanted to "ensure the American people receive the safest vaccines possible."
Doctors and health experts have criticised Kennedy's longstanding questioning of the safety and efficacy of a number of vaccines, although in his Senate confirmation hearing he said he is "not going to take them away."