How soon can we give the second dose of MMR vaccine to a child vaccinated at 12 months old?

For routine vaccination, children without contraindications to MMR vaccine should receive 2 doses of MMR vaccine with the first dose at age 12–15 months old and the second dose at age 4–6 years old. The minimum interval is 28 days for dose 2. If you have an outbreak in your community or a child is traveling internationally, then consider using the minimum interval instead of waiting until age 4–6 years old for dose 2.