Abstract
To investigate the combined effect of pneumococcal vaccination and penicillin prophylaxis on the progress of sickle cell disease, two groups of sickle cell disease patients, presenting with severe clinical manifestations of the disease were selected as cohorts. One group was vaccinated with the polyvalent pneumococcal vaccine and given penicillin prophylaxis, while the other group was not given the vaccine and penicillin. Pneumococcal vaccination and penicillin prophylaxis increase the crisis-free interval in sickle cell disease patients, and play a significant role in decreasing the morbidity associated with sickle cell disease.