Polyvalent pneumococcal polysaccharide vaccines

Summary It has been shown that polyvalent pneumococcal polysaccharide vaccine, now commercially available, is safe, antigenic, and provides protection against pneumonias caused by the pneumococcal serotypes which are present in the vaccine. Early studies also show protection against otitis media caused by these organisms (Makela, 1979). The vaccine is effective in persons with anatomical or functional splenic deficiency but there is a lowered antibody response in immunodepressed patients. Pneumococcal vaccine can be given simultaneously with influenza virus vaccine without significant depression in antibody response to either vaccine and without any increase in reactogenicity. The vaccine contains 14 serotypes that cause approximately 80 per cent of all pneumococcal illnesses, and it shows 80 per cent or greater protective efficacy against pneumonias caused by those serotypes present in the vaccine. Reactions to the vaccine are self-limited and consist generally of mild local and systemic responses. Children of two years of age or older generally respond well to the vaccine; those less than two years of age respond poorly to a majority of the serotypes. It appears that this deficiency may be overcome in part by giving two doses of vaccine at optimally spaced intervals that still remain to be defined. Immunity is expected to last for at least three years at which time booster immunisation might be considered. Reimmunisation at a 12–18 month interval showed no elevation in antibody and there was increased local reaction, apparently due to an ‘Arthus-like' reaction at the site of injection. This may be overcome by reduced dosage on revaccination but no firm recommendations can be formulated at this time.