After the last Following a series of mass layoffs at the U.S. Centers for Disease Control and Prevention over the weekend, the union that represents the agency’s employees estimates that about 3,000 people this year, or about a quarter of the agency’s workforce, have left the agency.

That number includes workers affected by layoffs earlier this year, as well as those who accepted the Trump administration’s “Fork in the Road” buyout program.

The most recent cuts took place against the backdrop of the current government shutdown. On October 10, more than 1,300 CDC employees received notice of layoffs. However, shortly thereafter, approximately 700 of these individuals were informed by email that they had been terminated in error and were in fact not subject to the reduction in force. It is estimated that 600 people remain laid off.

According to the union, an additional 1,300 CDC employees are on administrative leave and paid but not working.

The Trump administration has not shared official figures for who was targeted by the cuts. The estimate was compiled by American Federation of Government Employees (AFGE) Local 2883, which represents CDC workers.

The current round of cuts affects the National Center for Chronic Disease Prevention and Health Promotion, the National Center for Health Statistics, the CDC library, the agency’s human resources department, campus security personnel, as well as the CDC office in Washington, D.C., which serves as a liaison to Congress and provides public health information to policymakers.

“All HHS employees receiving reduction-in-force notices have been designated as non-essential by their respective divisions,” Andrew Nixon, communications director for the Department of Health and Human Services, told WIRED via email.

Among those reinstated are staff who publish the agency’s flagship publication, the Morbidity and Mortality Weekly Report, as well as leaders of the National Center for Immunization and Respiratory Diseases and the National Center for Emerging and Zoonotic Infectious Diseases, according to AFGE. Members of the Epidemic Intelligence Service, the CDC’s “disease detective” unit, were also brought back.

The CDC has been in turmoil since HHS Secretary Robert F. Kennedy Jr. took office in February. In addition to carrying out massive layoffs, Kennedy is attempting to overturn established vaccine policy. Earlier this year, he removed all 17 sitting members of a federal vaccine advisory committee, replacing them with members of his choosing. Many are skeptical of vaccines and have criticized public health measures taken during the Covid-19 pandemic.

In August, Kennedy fired CDC Director Susan Monarez, who had held the position for only a month. Monarez told a Senate committee in September that Kennedy demanded she approve new vaccine recommendations “without regard to scientific evidence” and fire career officials without cause. During his short time at the CDC, a gunman opened fire on the agency’s Atlanta campus and killed a police officer who responded to the shooting.