Seroprevalence and Placental Transportation of Maternal Antibodies Specific for Neisseria meningitidis Serogroup C, Haemophilus influenzae Type B, Diphtheria, Tetanus, and Pertussis

Background. Maternal antibodies contribute to the protection of neonates from infectious diseases during the first months of life. The seroprevalence of antibodies specific for polysaccharide or protein antigens from vaccine-preventable pathogens was determined in paired maternal delivery and cord blood serum samples. Methods. Antibody concentrations specific for Neisseria meningitidis serogroup C polysaccharide, Haemophilus influenzae type B polysaccharide, diphtheria toxin, tetanus toxin, and pertussis toxin, filamentous hemagglutinin, and pertactin from Bordetella pertussis were determined by enzyme-linked inmmunosorbent assay (ELISA), fluorescent multiplex immunoassay, or serum bactericidal assay. Results. We investigated 197 paired maternal delivery and cord blood samples. The mean maternal age was 30.8 years, and the mean gestational age was 39.3 weeks. Cord geometric mean concentrations (GMCs) were 0.23 mu g/mL for N. meningitidis serogroup C and 0.53 mu g/mL for H. influenzae type B. Cord GMCs to diphtheria and tetanus were 0.16 and 1.06 IU/mL, respectively, and cord GMCs to pertussis toxin, filamentous hemagglutinin, and pertactin were 16.2, 34.8, and 17.7 ELISA U/mL (by ELISA), respectively. Cord GMCs to polysaccharide were, in general, 107% identical to maternal GMCs, whereas cord GMCs to proteins were a mean of 157% of maternal concentrations. In addition, the levels of anti-N. meningitidis serogroup C immunoglobulin G1 and G2 in cord blood were 145% and 109% of maternal concentrations, respectively. Conclusions. Antibody concentrations directed toward polysaccharide were equal in maternal and cord blood, whereas antibody concentrations to proteins were 1.6 times higher in cord blood than in maternal blood. This is probably attributable to the less-active transportation of immunoglobulin G2 antibodies elicited by polysaccharide. Despite proper placental transfer, cord antibody concentrations are low, possibly placing neonates at risk before they receive their primary vaccinations.