Failure of pneumococcal vaccination in a splenectomized child.

Recurrent Streptococcus pneumoniae septicaemia occurred in a splenectomized child with idiopathic thrombocytopenic purpura. Fatal infection took place 1 year after pneumococcal vaccination and was caused by sero-type 18C which was included in the vaccine. The efficacy of pneumococcal vaccination is discussed in relation to specific pneumococcal polysaccharide antibody titers, and it is concluded that vaccination alone is insufficient in preventing overwhelming infections in splenectomized individuals.