FILE PHOTO: A general view of the Centers for Disease Control and Prevention (CDC) headquarters in Atlanta, Georgia September 30, 2014. REUTERS/Tami Chappell/File Photo

By Ahmed Aboulenein

WASHINGTON (Reuters) -Layoff notices sent over the weekend to U.S. CDC staff would see the agency lose almost a quarter of its workforce since President Donald Trump took office this year, the union representing them said on Tuesday.

The CDC notified some 1,300 employees they would be laid off on Friday night only to rescind around 700 on Saturday. The Department of Health and Human Services blamed a "coding error" for the notices it said went out mistakenly.

Around 600 employees are still on their way out, with the Trump administration seeking to lay off entire offices and hundreds of Centers for Disease Control and Prevention workers as part of mass job cuts during the federal government shutdown, now in its second week.

"These illegal firings of our union members during a federal government shutdown is a callous attack on hard working Americans and puts the livelihoods, health, and safety of our members and communities at great risk" said Local AFGE 2883 President Yolanda Jacobs on a call with media.

The 600 reduction-in-force notices, combined with earlier layoffs and voluntary early retirements, mean that the CDC has lost around 24% of its workforce since January, union officials said on a press call.

ENTIRE UNITS FACE TERMINATION

Human Resources workers were brought back from furlough and forced to send themselves RIF notices with effective dates of December 8, Jacobs said, and mental health professionals who have supported employees affected by an August 8 shooting at the CDC Atlanta headquarters are now facing termination.

Among those initially cut were staff responsible for the Morbidity and Mortality Weekly Report, a critical vehicle for disseminating public health findings. That unit, along with employees at the National Center for Immunization and Respiratory Diseases and early-career epidemiologists involved in outbreak investigations, have had their dismissals reversed.

Saturday's reversal is not the first time the CDC has changed course on job cuts. Earlier this year, HHS Secretary Robert F. Kennedy Jr. oversaw the dismissal of 2,400 employees, only to rehire 722 of them.

Kennedy, who has long promoted vaccine misinformation, has been highly critical of the CDC, putting the agency at the center of his efforts to remake the nation's immunization policies.

The weekend layoff notices include the entire staff of the CDC's Washington office, which works directly with members of Congress to provide data and briefings.

Others fired include the staffs of the CDC Library, its Office of Safety, Security, and Asset Management, and some staff at the National Center for Health Statistics.

Referring to comments by Trump budget chief Russ Vought, who said government workers needed to feel "trauma" in a speech before Trump was elected, Jacobs said: "One thing is clear, this administration has more than delivered on its promise to traumatize federal employees."

(Reporting by Ahmed Aboulenein; Editing by Bill Berkrot)