A sweeping downsizing ordered by Health and Human Services Secretary Robert F. Kennedy Jr. has led to an exodus of more than 20,500 employees from U.S. federal health agencies since January, according to a ProPublica analysis of internal staff directories published on 21 August. The Trump administration has described the cuts as an effort to eliminate “bureaucratic bloat,” but it has declined to release official head-count data. The departures span the government’s three largest health bodies. The Centers for Disease Control and Prevention has lost about 3,000 workers—15 % of its workforce—while the National Institutes of Health is down roughly 7,000 employees, or 16 %. The Food and Drug Administration has shed 21 % of its staff, including more than a quarter of the scientists and regulators in its biologics center, which oversees vaccine safety and production. Layoffs accelerated this week as the CDC issued permanent termination notices to roughly 600 employees, the American Federation of Government Employees said. The cuts, effective 18 August, affect programmes in violence prevention, equal-employment oversight and public-records compliance. They follow a court ruling that shielded some, but not all, CDC divisions from the broader restructuring announced in March—one that originally targeted 2,400 CDC positions and 10,000 jobs department-wide. Current and former officials warn the thinning ranks will slow clinical studies, food- and drug-facility inspections and outbreak response. “Public health isn’t a luxury—it’s a core function of government,” former HHS secretary Xavier Becerra said, calling the moves reckless. An HHS spokesperson countered that resources are being redirected toward “science that delivers measurable impact,” citing projected savings of $1.8 billion a year and the cancellation of $500 million in mRNA research contracts.