Evaluation of immunity against rubella in Iranian after mass campaign for measles-rubella vaccination on December 2003

Background: Prevention of congenital rubella syndrome (CRS) is the main goal of rubella immunization. The World Health Organization (WHO) recommends that countries undertaking measles elimination should take the opportunity to eliminate rubella as well through use of measles-rubella (MR) or measles-mumps-rubella (MMR) vaccine in their childhood immunization programs and campaigns. On December 2003, during a mass campaign for measles-rubella vaccination in Iran, more than 33 million doses of vaccine were administered to 5- to 25-year-old males and females. Methods: in this study immunoglobulin (Ig)G avidity assay was used to evaluate the rubella vaccine produced immunity among susceptible populations. Results: Findings indicated that 61.9% of vaccinees (1202 out of 1940) were immune against rubella before vaccination, and 38.1% (738 out of 1940) were susceptible to rubella before vaccination. Our results also showed that 98% of the susceptible group (723 out of 738) acquired immunity against rubella after vaccination, and 2% of them (15 out of 738) did not acquire vaccine-induced immunity to rubella. Conclusion: Findings revealed that mass vaccination in December 2003 provided appropriate immune coverage among vaccinees. Also, rubella vaccine induced favorable immunity in a part of the childbearing age female (15-25 years) population, which could prevent congenital rubella syndrome among those females.