Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Study design. Children were grouped on the basis of age at first receipt of measles, mumps, and rubella (MMR) vaccine: 6–8 months, 9–12 months, or 14 months. Ages at which blood samples were collected are indicated, as are the number of withdrawals recorded at each home visit. Numbers in colored boxes indicate the number of samples analyzed for each group at each time point. MMR-1, MMR dose received at age 14 months.
