Trump signs executive order seeking to reduce recommended childhood vaccinesThe move comes after a similar effort was blocked in court earlier this year. (NBC)- President Donald Trump is wading back into the debate over childhood vaccines with a new executive order seeking to reduce the number of recommended vaccines from 18 to 11. Trump suggested receiving the MMR vaccines together could be dangerous but acknowledged when questioned that he did not have evidence supporting that claim. The Centers for Disease Control and Prevention says there is no published scientific evidence supporting separating the MMR vaccine into individual shots. Legal experts say the executive order is likely to face challenges in court.