In 2019, Kennedy’s activism was implicated in a measles outbreak in Samoa that infected 5,700 and killed 83. Kennedy had personally visited Samoa earlier that year, and was pictured with local anti-vaccine advocates at the US embassy. This was followed by his Children’s Health Defense organization sending a letter to the president of Samoa, urging him to question the safety of the MMR vaccine, which protects against measles, mumps, and rubella.