Infections in sickle cell anemia: pathogenesis and control.

Splenic dysfunction accounts for the greatest deficit in immune function in children with homozygous SCD. This dysfunction, coupled with the natural immunologic immaturity of all young children subjects the young child with SCD to an immense risk of severe pyogenic infections. To data, experience would suggest that pneumococcal vaccines may provide only modest protection in the child with SCD less than 5 years of age. Antipneumococcal antibody responses are poor in children less than two years of age. All reported failures of pneumococcal vaccine among children with SCD have occurred in children less than three years of age and offending pneumococci have been of groups 6 and 23. Prophylactic antibiotic regimens have yet to be submitted to rigid scientific investigation and their utility in eliminating the risk of pneumococcal sepsis in asplenic hosts is unknown.