From March 10 to May 10, 1990, 40 cases of rubella occurred in a girls' elementary school in Riyadh, Saudi Arabia, prompting concerns about vaccine efficacy and coverage. Case detection was enhanced in the school and in the community. Vaccination status was determined from school records and vaccination cards. Attack rates among the vaccinated and unvaccinated girls in affected classes were compared. A total of 56 rubella-like illnesses were identified from the school and the community. The attack rate in the school was 7.8%, but it exceeded 18% in three classrooms. Vaccine efficacy was 94% (95% CI 75-98). However, only 46% of exposed students were previously vaccinated against rubella. Six unvaccinated pregnant teachers and 17 pregnant community contacts were exposed. Rubella vaccine as administered through national and school programs has resulted in excellent efficacy. If full protection of the susceptible population becomes a goal, then higher coverage rates of school age children will be needed.
Conclusion: