"Three cases of immune thrombocytopenic purpura after the first dose of recombinant hepatitis B vaccine have occurred in infants less than 6 months of age. Other possible causes of this condition have been ruled out. Antiplatelet antibodies were present. In two children it is A defect in platelet production was ruled out. Treatment with corticosteroids was effective. Subsequent administration of other vaccines (against poliomyelitis, diphtheria and tetanus) did not cause a relapse of thrombocytopenia ".