MMR Vaccine Schedule
For children, the standard dosing schedule for the MMR vaccine (officially known as M-M-R® II) calls for the first dose to be given when the child is between 12 and 15 months old. The second injection is typically administered right before the child starts elementary school.
While the vaccine is typically given to prevent infection in people who have not been exposed to the viruses, it may also be used in an outbreak situation. In this case, dosing guidelines allow the MMR vaccine to be given to infants as young as six months old.
Depending on your state requirements for school entry, your child may be able to skip the second dose if you can provide documentation (through blood tests) that your child is immune to measles, mumps, and rubella. The second dose of MMR is not considered a "booster" dose (providing additional protection from the diseases). Instead, it is used to provide immunity for people who failed to respond to the first dose, for whatever reason.
(Click MMR Dosage to learn more about MMR vaccine schedules, including the dosing schedule for adults.)