Symptom-free intervals in sicklers: does pneumococcal vaccination and penicillin prophylaxis have a role?

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. Clinical manifestations, frequency of hospitalization, crises and blood transfusion requirements, haematological parameters, and differential counts were recorded for each patient in the two groups. The 'severity index' of the sickle cell disease was calculated for each patient. No significant differences were encountered in the values of the haematological parameters except for the white cell count which was significantly higher in the non-vaccinated group. However, the frequency of hospitalization, crisis, and blood transfusion were significantly higher in the non-vaccinated group compared to the vaccinated group. Clinical symptoms frequently associated with severe sickle cell disease, were also encountered at a higher frequency in the non-vaccinated group. These results show that 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.