President Donald Trump signed an executive order on Monday aimed at reshaping the federal government’s approach toward childhood vaccines, insisting that infants should receive fewer immunizations over a longer period despite little scientific evidence supporting such sweeping changes.

The World Health Organization on Tuesday defended the science-based process used to determine childhood ‌immunisation schedules after U.S. President Donald Trump signed an executive order aimed at red...

The order will recommend separating the measles, mumps and rubella (MMR) vaccine into three different shots administered in separate visits, and direct the nation’s health department to improve vaccin...