Prevalence of measles antibody in children of different ages in Shiraz, Islamic Republic of Iran.

An outbreak of measles due to secondary vaccine failure prompted this investigation into the prevalence of measles antibody in children. We studied 608 children in 7 different age groups: 6, 9, 14 and 18 months and 6, 10 and 15 years. Children in the 2 youngest groups received no vaccination; the rest were vaccinated at 9 months and 15 months. The 15-year-old age group received an additional vaccination. Transplacental measles antibody (Ab) decreased from 10.0% at 6 months to 0% at 9 months. Measles Ab was positive in 52.9% (14 months), 89.4% (18 months), 60.8% 96 years), 45.0% (10 years) and 96.8% (15 years). To increase Ab levels, a booster vaccination is recommended, administered either with the second DPT booster or at pre-high school age.