The Trump administration on Saturday raced to rescind layoffs of hundreds of scientists at the Centers for Disease Control and Prevention who were mistakenly fired on Friday night in what appeared to be a substantial procedural lapse.

Among those wrongly dismissed were the top two leaders of the federal measles response team, those working to contain Ebola in the Democratic Republic of Congo, members of the Epidemic Intelligence Service, and the team that assembles the C.D.C.’s vaunted scientific journal, The Morbidity and Mortality Weekly Report.

After The New York Times reported the dismissals, two federal health officials said on Saturday that many of those workers were being brought back. The officials spoke anonymously in order to disclose internal discussions.

The mistakes rocked an agency already in tumult, and which has been a particular target of Health Secretary Robert F. Kennedy Jr. The C.D.C. lost about a third of its staff in April; many were rehired weeks later.