The news: President Trump fired the head of the CDC less than a month after she was approved by the Senate. At least four other senior leaders at the agency also resigned. Director Susan Monarez accused HHS and Secretary Robert F. Kennedy Jr. of “weaponizing public health for political gain and putting millions of American lives at risk,” per a statement from her lawyers.

How we got here: Monarez was sworn in as CDC director on July 31, but her short term was marred by turmoil. She started the job amid fallout from Kennedy’s dismissal of the entire CDC vaccine advisory panel in June. He replaced them with a handpicked group that includes vaccine skeptics.

Two weeks ago, a gunman fired hundreds of shots at the CDC headquarters in Atlanta and killed a police officer in a targeted attack related to COVID-19 vaccine misinformation. Monarez faced criticism after the shooting for not speaking out about vaccine misguidance from HHS leaders, including Kennedy.

Kennedy and Monarez disagreed about vaccine policy, and earlier this week, Kennedy demanded her resignation, per The New York Times. She refused and Trump fired her on Wednesday night. Meanwhile, the CDC’s chief medical officer and the heads of vaccine safety, vaccine recommendations, and public health data resigned.

Yes, and: The firing and resignations came on the same day Kennedy narrowed approval for COVID-19 vaccines. The FDA now only recommends the vaccine for high-risk groups—people ages 65 and older and younger people who have certain underlying health conditions.