Democratic senators are calling for an investigation into Health and Human Services Secretary Robert F. Kennedy Jr., accusing him of making false statements to Congress about a 2019 trip to Samoa that he repeatedly said had “nothing to do with vaccines.”

Kennedy’s visit to the Pacific island nation became a point of controversy during his confirmation process last year. He traveled to Samoa months before a measles outbreak swept through the country, killing 83 people. At the time, Kennedy was leading a nonprofit organization known for its anti-vaccine activism.