Maintenance of an Immunogenic Response to Pneumococcal Vaccination in Children With Sickle Cell Disease

Patients with sickle cell disease (SCD) are at increased risk for invasive pneumococcal disease because of splenic dysfunction. To mitigate this risk, patients are protected with prophylactic penicillin until completion of pneumococcal vaccination series. The objective of this study was to assess the maintenance of a protective immune response to pneumococcal vaccination in children with SCD. A retrospective review was conducted between June 2019 and June 2020 of all patients with SCD patients for whom it had been 5 +/- 1 year since completion of PPSV23 vaccination series. A total of 41 patients were analyzed. The majority of children (68%) were able to maintain an adequate immune response. There was no identifiable disease characteristic associated with maintenance of an appropriate immunogenic response. This study finds that patients with SCD are able to maintain an adequate immune response at the 5 +/- 1 year time point from completion of PPSV23 vaccination series. Similarly, patients were not found to have an increased rate of invasive pneumococcal disease even if not meeting criteria for adequate pneumococcal serum titer levels. Maintenance of pneumococcal titers suggests that there may not be a need for revaccination at the 5-year time point in this patient population.