In 2018 two nurses in Samoa prepared what should have been routine measles, mumps, rubella (MMR) vaccines with an expired anesthetic instead of water, and administered them to two infants, who died. The Samoan government suspended vaccinations for 10 months, and the nation was bombarded with anti-vaccination messages, including from RFK Jr. and his nonprofit Children’s Health Defense. That year only 31% of Samoan children received the MMR vaccine, leading to nearly 3,000 infections in the nation of 200,000, and 39 deaths by November 2019. Kate O’Brien, head of the World Health Organization’s (WHO) immunization department at the time, told the Guardian that the effect of misinformation about vaccine safety was “being measured in the lives of children who had died” in the course of the outbreak. By January 2020 5,700 people had been infected, resulting in 83 deaths, with most of the victims under 5 years old.

Kennedy was an independent candidate for the presidency in 2024, but suspended his campaign August 23 throwing his support behind Donald Trump. On November 14, 2024 Trump announced that RFK Jr. would serve as Secretary of the Department of Health and Human Services, contradicting then-Trump-spokesman Howard Lutnick’s denial to CNN that Kennedy would have a role in a Trump HHS department.