US President Donald Trump speaks before signing an executive order calling for more research and flexibility on vaccines, in the Oval Office of the White House in Washington, DC, on August 10, 2026. Trump signed an executive order Monday pushing for a rethink of school vaccine mandates and repeating calls for the measles-mumps-rubella vaccine to be separated into three individual shots. Curbing vaccines has been a key priority for Health Secretary Robert F. Kennedy Jr, who founded an anti-vaccine nonprofit and has long promoted a disproven link between immunization and autism. (Photo by Jim WATSON / AFP via Getty Images)