President Donald Trump signed an executive order Monday to reshape the nation’s childhood vaccine schedule after earlier changes attempted by Health Secretary Robert F. Kennedy Jr. were blocked in court. The order calls for splitting up childhood vaccines into three categories, with different recommendations for who should get them, and directs federal agencies to implement the changes. Earlier this year, Kennedy bypassed a panel of vaccine advisers to pare the number of recommended childhood vaccines from 17 to 11, although courts have blocked that move thus far. Kennedy pledged that the Department of Health and Human Services would deliver on the executive order within 90 days. The NIH has been overseeing a research initiative to seek possible causes of autism, which Trump and health officials announced last September.