The decision was a small but significant example of the uncertainty engulfing the CDC, which now answers to Robert F. Kennedy Jr.—a longtime promoter of false claims about vaccine safety, along with other pseudoscientific notions, who was confirmed as the US secretary of health and human services on Feb. 13. As many as 700 CDC employees have been told they will lose their jobs, including hands-on scientists and lab personnel. Many were informed of their terminations in emails that said their “performance has not been adequate to justify further employment.”