The Centers for Disease Control and Prevention (CDC) is facing unprecedented leadership instability following the abrupt departure of Director Susan Monarez just weeks into her tenure. The ouster coincided with the FDA's decision to narrow COVID-19 booster vaccine approvals to select high-risk groups, reflecting tensions within the federal health agencies. Multiple senior CDC officials have resigned amid concerns over politicization, vaccine messaging, and internal conflicts, raising alarms about the agency’s pandemic preparedness and public health capacity.