svg]:overflow-visible">Listen to article • 0:00 minFalse choiceThe plan to split the measles, mumps, and rubella vaccines into three separate shots is being sold as another option for parents. It isn’t one, not for years, maybe not ever. No single-antigen measles, mumps, or rubella vaccine is licensed in the United States. Merck stopped making the old separate versions in 2008, concluding that three shots offered no medical benefit over one and simply meant more needles and more missed appointments. Rebuilding them means new clinical trials, new manufacturing lines, and years of FDA review; Merck’s own estimate runs past a decade, and no...