Tracy Beth Høeg was appointed acting director of the FDA’s Center for Drug Evaluation and Research as the agency cycles through leadership after multiple changes in 2025. Her appointment has drawn scrutiny because of her published work and ties to debates over vaccine safety and approval pathways. Industry groups and analysts flagged the leadership churn as a destabilizing factor for vaccine developers. The mRNA coalition and other industry stakeholders have publicly demanded steady FDA leadership, warning that turmoil risks eroding public trust and slowing approvals. Analysts say the leadership changes could influence FDA policy on vaccine trial size and evidentiary standards.