Estimated seroprevalence (%) of rubella IgG in the assessment population, by age group and study site in Bandundu, Kasaï Occidental, and Kinshasa provinces, Democratic Republic of the Congo. Equivocals were classified as seronegative in these analyses. Footnote: For each age group and overall, the number of serum samples analyzed by enzyme-linked immunosorbent assay (ELISA) is noted. Within the Kinshasa site, the 20–24 year age group had a higher antibody seroprevalence than the 15–19 (p value = 0.01) and 25–29 (p value < 0.001) year age groups. Kikwit (89%) and Vanga (88%) study sites had higher overall rubella antibody seroprevalence than the Mikalayi (80%) and Kinshasa (82%) sites (all p values ⩽0.03).