The FDA named Tracy Beth Høeg as acting director of the Center for Drug Evaluation and Research amid rapid leadership turnover at CDER. Høeg, an epidemiologist who worked on high‑profile vaccine safety analyses, steps in at a moment of heightened internal scrutiny and shifting regulatory priorities. Separately, a group of 12 former FDA commissioners publicly criticized proposed changes from the agency’s biologics office that would tighten rules around vaccine updates and trial size, saying the moves risk undermining established standards. The comments and leadership changes underscore intensifying political and scientific tensions inside the agency over vaccine policy, trial evidence requirements and regulatory predictability.