Antibody response to group B streptococcus type III and AB blood group antigens induced by pneumococcal vaccine

The effect of pneumococcal vaccination on antibodies to Streptococcus pneumoniae type 14, group B streptococcus type III, and AB blood group antigens was studied in 40 vaccinated adults. Fourfold or greater increases in type-specific IgG antibody to Pn-14 were found in 26 of 40 vaccines (mean increase 6.4-fold) and against GBS-III in 16 of the 40 (mean increase 2.9-fold) by an indirect immunofluorescence assay. However, only six of the 26 vaccinees with low levels (titers less than or equal to 20) of GBS-III antibody in prevaccination sera developed titers greater than 20 after vaccination. Thus, vaccination with polyvalent pneumococcal vaccine does not reliably induce high levels of IF antibody to GBS-III. Fourfold or greater increases in IgG isohemagglutinins against blood group A cells were also found in 22 of 27 vaccines (mean increase 4.5-fold) and against blood group B cells in nine of 34 (mean increase 1.7-fold) using the indirect anti-human globulin test. Chromatographic fractionation of selected sera confirmed that the anti-A isohemagglutinins stimulated in group O subjects were of the IgG class. Thus, pneumococcal vaccination during incompatible pregnancy could potentiate AO hemolytic disease of the newborn infant.