Safety and antibody persistence following Haemophilus influenzae type b conjugate or pneumococcal polysaccharide vaccines given before pregnancy in women of childbearing age and their infants

Background. Immunization of healthy women before pregnancy is a potential a pproach to providing increased levels of maternal antibody to newborns to p rotect them from infections occurring during the perinatal period and first months of life. Methods. Healthy nonpregnant Pima Indian women of childbearing age were ran domized to receive one of two Haemophilus influenzae type b (Hib) conjugate vaccines [HbOC or Hib-meningococcal outer membrane protein complex (OMP)] or a 23-valent pneumococcal polysaccharide vaccine (PnPs). Infants received Hib-OMP vaccine at 2, 4 and 12 months of age. Vaccine safety and immunogen icity was evaluated in the women and their infants. Results. Anti-polyribose ribitol phosphate antibody titers were significant ly higher in women in both Hib conjugate vaccine groups than in the pneumoc occal vaccine group throughout the 37-month observation period. Antibody re sponses to HbOC vaccine were significantly higher than those to Hib-OMP. A subsequent booster dose of each Hib conjugate vaccine induced reactions and antibody responses similar to those of the first dose. Infants born to mot hers immunized with Hib vaccines compared with PnPs had significantly highe r polyribose ribitol phosphate-specific IgG antibody titers at birth and 2 months of age but lower antibody responses to Hib-OMP at 6 months and simil ar titers before and after boosting with Hib-OMP at 1 year of age. By contr ast women immunized with PnPs did not have significantly elevated concentra tions of pneumococcal-specific antibody at delivery, and their infants had pneumococcal antibody titers similar to those of infants born to mothers wh o did not receive pneumococcal vaccine before pregnancy. Conclusion. Hib conjugate vaccine given to women before pregnancy significa ntly increased the proportion of infants who had protective Hib antibody le vels at birth and 2 months of age.