The impact of maternal measles-rubella immunization on the 12-month-old infant's immune response to measles-mumps-rubella vaccine immunogenicity.

This study was conducted to assess the roles of maternal measles-rubella (MR) vaccination before pregnancy on the persistence of passive immunity against MR in their infant before measles-mumps-rubella (MMR) immunization and the effects on the immunogenicity of MMR vaccine. Before and 4-8 weeks after MMR immunization of all healthy 12-month-old infants, sera samples were prepared. According to their mother's history of MR vaccination, infants were divided into two groups. Anti-MR antibodies were measured by the quantitative enzyme-linked immunosorbent assay (ELISA) method. The difference in seroconversion rates and the mean concentration of antibodies (MCA) between the two groups of infants were analyzed by descriptive statistical methods. In total, 7 and 12 sera, all from infants born from MR-vaccinated mothers, were positive against measles and rubella, respectively. The seroconversion rates were 90.5 and 53% in seronegative infants against measles and rubella, respectively, without statistically significant differences between the two groups of infants. However, the MCA differences were significant; measles P = 0.000, rubella P = 0.019. The MR vaccination of mothers may cause the prolongation of passive immunity in their infants, and may influence the immunogenicity of MMR vaccination. This finding should be considered for the optimal scheduling of the first dose of MMR vaccine. Also, the results showed that the immunogenicity of the rubella component of the MMR vaccine was lower than that reported.