sceptic

Health Secretary Robert F Kennedy Jr, a vaccine sceptic, fired all 17 members of the committee in June and handpicked their successors, sparking uproar in the medical community.

He ousted all members of an independent vaccine advisory committee before replacing them with several vaccine sceptics, and has narrowed recommendations for Covid-19 booster shots.

Bolsonaro was also a vaccine sceptic, resisting offers to buy jabs for his population and refusing to get one himself.

The exodus comes as health experts voice concern over the agency's approach to immunisations under the leadership of Kennedy, a vaccine sceptic.

The ban has its sceptics, including students, who question how it would work, its wider implications and whether it is addressing the root cause of addiction.