Why the MMR vaccine is given as one shot, and what separating it could mean

President Donald Trump signed an executive order recommending the MMR vaccine be split into three separate shots. Doctors say that could lead to missed vaccines.

​President Donald Trump signed an executive order recommending the MMR vaccine be split into three separate shots. Doctors say that could lead to missed vaccines.  Health President Donald Trump signed an executive order recommending the MMR vaccine be split into three separate shots. Doctors say that could lead to missed vaccines.