Antibody response to pneumococcal vaccine in splenectomized children

The antibody response, measured as total immunoglobulin, of 66 splenectomized children to a 14-valent pneumococcal capsular polysaccharide vaccine was determined by an enzyme-linked immunosorbent assay. It did not differ significantly from that of 12 non-splenectomized children for 10 of the 14 polysaccharide antigens studied, but was lower for polysaccharide types 2, 3, 8 and 12F. Significant responses of both IgG and IgM antibody against all four antigens studied were found in 10 splenectomized and against all 14 antigens in five non-splenectomized children. In 2/10 splenectomized and 1/5 non-splenectomized children the arbitrary IgG/IgM ratio was below 1 in contrast to the pattern found in the other 12 patients. The increase in anti-pneumococcal antibody after vaccination in seven non-splenectomized children receiving corticosteroid therapy was only significantly lower than that of 12 untreated non-splenectomized children against two of the 14 antigens, and similar or higher against all antigens in five splenectomized children receiving steroid therapy compared to 66 splenectomized children not receiving such therapy. In 22 splenectomized children 70% of the peak geometric mean total antibody concentration four weeks after vaccination was still present after two years. Adverse reactions to the vaccine included local reactions at the vaccination site in 56% and fever in 9%. Side-effects were correlated to the geometric mean concentration of total antibody present at the time of vaccination. Immunogenicity of each of the 14 vaccine antigens varied considerably, as did the responses of different individuals.