WASHINGTON ‒ The White House named Jim O'Neill, a top deputy of Health and Human Services Secretary Robert F. Kennedy Jr., the acting director of the Centers for Disease Control and Prevention after firing Susan Monarez the day before.

O'Neill, who was the deputy HHS secretary, will replace Monarez on an interim basis, a Trump administration official confirmed on Aug. 28 to USA TODAY, after Monarez was fired following a dispute with Kennedy over vaccination policy. In his current role, O'Neill oversees all operations in the sprawling HHS department.

Monarez's ouster, which her attorneys have contested, came less than one month after the Senate confirmed her to the role. Her dismissal was followed by resignations from three other top CDC officials in protest of Kennedy's leadership, including his direction on vaccines. Kennedy is a longtime vaccine skeptic.

More: White House fires CDC Director Susan Monarez after clash with RFK Jr., but she refuses to quit

O'Neill's promotion was first reported by the Washington Post.