Robert F. Kennedy Jr. is facing fire from his own people. The U.S. health secretary has angered anti-vax activists by extending liability protections to drugmakers working on a hantavirus vaccine. Kennedy signed a Public Readiness and Emergency Preparedness, or PREP, Act declaration late last week, giving pharmaceutical companies additional legal coverage as they work on experimental treatments—such as favipiravir—during the public health crisis. “This action helps remove barriers to research