Despite a safe and effective vaccine, endemic rubella remains a problem in developing countries. Isolated cases and outbreaks can occur in areas with high vaccine coverage. Individuals, especially pregnant women who remain unimmunized or do not seroconvert, are susceptible to infection and their infants are at risk for congenital rubella syndrome (CRS). Both humoral and cellular immune responses contribute to immune protection. Classically, immunity to rubella has been assessed through the detection of rubella-specific antibody titers. In this study we examined correlates of both humoral and cellular immunity in a large population of immunized young adults in Olmsted County, MN. We were unable to find any significant correlation between cytokine production after in-vitro rubella stimulation and serum antibody titers.