The Public Health Improvement Act aims to reform the Centers for Disease Control and Prevention (CDC) and limit the scope of public health authorities in the United States. The main objectives are to establish term limits for the directors of the CDC and the National Institutes of Health (NIH), redefine the CDC's strategic focus, and enhance congressional oversight during public health emergencies. Key provisions of the Act include setting a maximum of 12 years for individuals to serve as directors of the CDC and NIH.