Susan Monarez, less than a month into the job as CDC director, entered a meeting Monday with health secretary Robert F. Kennedy Jr. and his deputy, Stefanie Spear. They asked for her resignation, citing concerns about insubordination and her integrity, including instances related to vaccine policy.

When she refused, Kennedy offered her another choice: Accept all recommendations from the agency’s vaccine advisory committee, whose new members he had hand-picked, and fire a number of high-level officials at the agency. 

Barely two weeks after the shooting at the agency, Monarez declined again to step down, kicking off a days-long struggle between her and Kennedy over the leadership — and future — of the CDC and vaccine policy.