Immune Response to Pneumococcal Vaccine in Mothers to Infants with Group B Streptococcal Septicemia: Evidence for a Divergent IgG/IgM Ratio

摘要

Eight women who had given birth to infants contracting neonatal septicemia with group B streptococci (GBS) were immunized with a 14-valent penumococcal vaccine (Pneumovax®). Type-specific IgM and IgG antibodies against 6 pneumococcal types were determined before and after vaccination. Ten healthy age-matched women were also vaccinated and served as controls. The study group showed significantly higher preimmune IgM levels against 3 of the 6 pneumococcal antigens, and lower IgG levels against 1 antigen. However, 6 weeks as well as 1½ years after the immunization, no significant differences in IgG or IgM antibody levels could be demonstrated between the 2 groups. Before vaccination, significantly more study group women showed an arbitrary IgG/IgM ratio below 10 against pneumococcal types 1, 6A, 7F, 14 and 23F. Six weeks later, this ratio remained significantly low in the study group for antibodies against types 14 and 23F. 1½ years after vaccination, the ratio was significantly lower for antibodies against 2 other types, 6A and 7F. We suggest, as a working hypothesis, that mothers of GBS-infected infants differ in their capacity to switch from IgM to IgG producti