08/11/2026
A new executive order will upend the childhood vaccine schedule again. Per the order, MMR should be given as three separate single-disease shots once those products become available domestically, and all childhood immunizations should be administered at separate medical visits wherever feasible.
Those separate products don't exist. There are no standalone measles, mumps, or rubella vaccines licensed in the United States. Merck announced in October 2009 that it would not resume production of them, and said at the time there was no medical reason to give the three antigens separately. Bringing them back would mean restarting production, generating the evidence FDA requires, and getting approval-- this takes years.
So please don't delay your child's MMR waiting for a product that isn't available. Measles is circulating right now, and every month of waiting is a month your child isn't protected.
MMR was combined on purpose. Researchers tested whether putting three live viruses into one shot would make them work less well or cause more reactions, and it didn't. The other half of the reasoning is something any parent already understands: fewer needles and fewer trips to the pediatrician.
We've seen people claim the combination was never properly tested. That is absolutely not true. It was studied as a combination, and children were followed for years afterward. When GSK wanted US approval for a second MMR vaccine, it had to prove itself directly against Merck's in randomized trials under modern standards.
Does MMR carry risks? Of course. Everything does. About one fever-triggered seizure per 3,000 to 4,000 vaccinated children, and roughly one case of a temporary bleeding condition called ITP per 40,000. Splitting doesn't make those go away, and there is no published evidence that separating MMR provides a safety benefit.
Splitting would add needles and appointments. Two doses of MMR is two shots. Two doses of three separate vaccines is six. In one study, completion of recommended vaccines fell from 99.5% when two injections were needed to 88.9% when five were needed.
Nothing about your child's schedule changes today. MMR is available, and it keeps millions upon millions of children (and adults!) safe every single day.
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