The United States is a wealthy nation that lavishes spending on health care, supports a world-class biomedical research effort and was top-ranked for pandemic readiness. So why was it such a failure when covid-19 hit? A major reason was that our public health agencies, from local and state governments to the Centers for Disease Control and Prevention, were overwhelmed. The CDC director, Rochelle Walensky, has called for rebuilding public health in the United States, and it is none too soon.