Definition
For children born in the 3 to 5 years before the survey, VACMMR1 indicates whether the child has received the first in a series of MMR vaccinations, which vaccinate against measles, mumps, and rubella.
The measles, mumps, and rubella vaccination primary series usually consists of either 1 or 2 administrations, and the complementary variable VACMMR2 reports the second administration.
VACMMR1 uses composite coding, with a first digit of 2 indicating the child has been vaccinated and the second digit indicating the source of information (a dated entry on the vaccination card, an undated mark on the vaccination card, or the mother's report).