Health Secretary Robert F. Kennedy Jr. has fired a top official with the National Institutes of Health who blew the whistle on internal clashes over vaccine research in the early months of the Trump administration. On Wednesday, Dr. Jeanne Marrazzo received a letter from Kennedy — which CBS News reviewed — informing her that her role leading NIH's National Institute of Allergy and Infectious Diseases, or NIAID, had been terminated. He did not cite a cause beyond his constitutional authority to