NEW YORK — President Donald Trump on Monday signed an executive order calling for revamped childhood vaccine recommendations that promote his long-held belief that childhood shots should be spaced out into separate medical visits. Even as the order calls for revised vaccine recommendations, states, not the federal government, have the authority to require vaccinations for schoolchildren. Last December, Trump ordered HHS to review how peer nations approach vaccine recommendations and consider revising U.S. guidance accordingly. Trump publicly prodded the health secretary for an update on autism research in a Cabinet meeting last month. “How are you doing on the autism research?”