The current target groups for measles, mumps and rubella vaccination in the Islamic Republic of Iran are children at 12 months and 4-6 years. A study of the age-specific seroprevalence of antibodies against mumps in children aged 3-18 years in Shahrekord aimed to establish the need for booster vaccinations to cover non-immune children. Of 338 children, 19.8 were seronegative. Age-specific seronegativity was 33.3, 20.5 and 4.6 in age groups 7-11, 12-14 and 15-18 years respectively. To obtain herd immunity, we suggest that for the next 5 years children aged 7-11 years entering guidance school are selected as the main group for vaccination
