Drastic “reductions in force” are upending agencies within the Department of Health and Human Services (HHS), including the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA).

Thousands of people who work at the CDC were notified by email today that they were subject to the Trump administration’s efforts to cull federal workforce jobs, Wired reports. Top officials were among those either put on administrative leave, laid off, or reassigned to remote roles, the Washington Post reports.

HHS announced last week that it would slash its workforce by 20,000 people. Now, the nation is starting to see how that purge is rolling out, affecting programs meant to prevent and treat HIV infection and sexually transmitted disease, respiratory diseases, and foodborne illnesses, to name a few.

“We’re going to have patients die, Jade Pagkas-Bather, an infectious disease doctor at the University of Chicago, tells Wired. “Unnecessary, preventable death.”

HHS, on the other hand, says the changes will save $1.8 billion a year. “Over time, bureaucracies like HHS become wasteful and inefficient even when most of their staff are dedicated and competent civil servants,” HHS Secretary Robert F. Kennedy, Jr. said in a press release when HHS announced its restructuring last week. Kennedy is a staunch anti-vax crusader who has spread disinformation falsely linking vaccines to autism.

The FDA’s Center for Biologics Evaluation and Research (CBER) regulates vaccines, and director Peter Marks resigned on Friday, writing that “it has become clear that truth and transparency are not desired by the Secretary, but rather he wishes subservient confirmation of his misinformation and lies.”

“The FDA as we’ve known it is finished, with most of the leaders with institutional knowledge and a deep understanding of product development and safety no longer employed,” Robert Califf, FDA commissioner under Joe Biden and Barack Obama, wrote on LinkedIn today.

In an email to The Verge, HHS press secretary Vianca Rodriguez Feliciano maintains that “ongoing critical public health efforts will remain a top priority and will not be impacted by this administrative realignment.”