The order recommends separating the measles, mumps and rubella (MMR) vaccine into three separate single-disease shots and administering childhood vaccines at separate appointments whenever possible. They noted that childhood vaccines and how they should be given have been rigorously studied around the world for decades, and continue to prove to be safe and effective at protecting children. Doctors point out that separate vaccines for measles, mumps and rubella are not available in the United States. “There are many, many, many years of scientific data highlighting the safety of vaccines in children.” During the executive order signing, Kennedy and Trump suggested that childhood vaccines may play a role in causing autism.