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.

Dozens of employees at the Centers for Disease Control and Prevention — including “disease detectives,” high-ranking scientists and the entire Washington office — were notified late Friday that they were losing their jobs as part of the Trump administration’s latest round of federal layoffs.

It was unclear on Friday how many C.D.C. workers were affected. But it was the latest blow to an agency that has been wracked by mass resignations, a shooting at its Atlanta headquarters in August and the firing of its director under pressure from Health Secretary Robert F. Kennedy Jr.

Layoff notices landed in the email inboxes of C.D.C. employees shortly before 9 p.m. Eastern time on Friday, notifying employees that their duties had been deemed unnecessary or “virtually identical” to those being performed elsewhere in the agency. Scientists, including leaders, in offices addressing respiratory diseases, chronic diseases, injury prevention and global health were among those affected.