More than 750 current and former employees of the U.S. Department of Health and Human Services have sent a letter to Health Secretary Robert F. Kennedy Jr. and members of Congress accusing him of spreading medical misinformation and placing federal health workers at risk. Signatories from the CDC, National Institutes of Health and other HHS units say Kennedy’s rhetoric undermines public trust and contributed to the deadly 8 August attack on the CDC’s Atlanta headquarters. Georgia investigators say the 30-year-old gunman who killed police officer David Rose and fired hundreds of rounds at six CDC buildings held deep grievances about the COVID-19 vaccine. The letter argues that Kennedy’s public doubts about vaccine safety, including his dismissal of mRNA shots as ineffective and his description of the CDC as a “cesspool of corruption,” have intensified harassment of agency staff. The authors call on Kennedy to cease disseminating inaccurate health claims, publicly affirm the CDC’s scientific integrity, and institute stronger security measures—such as enhanced emergency alerts and removal of online “watchlists” that identify employees—by 2 September. They also urge him to rescind recent personnel decisions, including the ouster of the CDC’s vaccine advisory panel, which they say weakened preparedness. In a separate statement, HHS said Kennedy “stands firmly with CDC employees” and condemned violence against health workers, noting that the secretary traveled to Atlanta after the shooting. Kennedy has not directly addressed the demands laid out in the letter.