RFK Jr. Faces Senate Grilling After Vaccine Changes and C.D.C. Shake-Up

A three-hour hearing before the Senate Finance Committee revealed that the health secretary was on uncertain ground even with some Republicans who voted to confirm him.Health Secretary Robert Kennedy Jr. at Thursday’s hearing, which descended into a free-for-all, in part over Mr. Kennedy’s approach to vaccination, the turmoil at the Centers for Disease Control and Prevention and especially his decision last week to fire Susan Monarez, the C.D.C. director.