Two Democratic senators, Ron Wyden and Angela Alsobrooks, are investigating whether Health Secretary Robert F. Kennedy Jr. lied to Congress about his 2019 Samoa trip, after Associated Press and Guardian reporting in August 2026 published a letter in which he mentioned vaccines eight times despite telling senators the visit had "nothing to do with vaccines." The senators wrote to Children's Health Defense that they intend to hold Kennedy accountable for any false statements to Congress, while the Department of Health and Human Services has called claims that he lied outright defamatory.