U.S. Health and Human Services Secretary Robert F. Kennedy Jr. will testify before the Senate Finance Committee on 4 September, a hearing originally billed to review President Donald Trump’s 2026 health-care agenda but now overshadowed by a leadership crisis at the Centers for Disease Control and Prevention. The appearance was scheduled one day after the White House dismissed CDC Director Susan Monarez less than a month into her Senate-confirmed tenure. Monarez’s lawyers contend the termination is legally deficient, arguing only the president can remove her. Within hours of her ouster, three senior CDC officials resigned in protest, deepening uncertainty at the agency. Senate scrutiny is mounting. Finance Committee member Bill Cassidy, who also chairs the Health, Education, Labor and Pensions Committee, said the departures “will require oversight” and separately urged the CDC to postpone its 18 September meeting of the Advisory Committee on Immunization Practices, citing questions about the panel’s composition and the turmoil in agency leadership. Democrats are also pressing for answers. Sen. Bernie Sanders, the top Democrat on the HELP panel, called for a bipartisan investigation into Monarez’s firing, while Republican moderate Susan Collins said she was “extremely alarmed” by the move. Kennedy, a longtime critic of mainstream vaccine policy, has already faced backlash for replacing ACIP’s membership in June and for tightening access to COVID-19 shots. Lawmakers from both parties are expected to question him next week on how his vaccine agenda and the abrupt shake-up at the CDC align with the administration’s broader public-health goals.