COVID-19 Vaccine Response in Sickle Cell Disease

Sickle cell disease (SCD) is a genetic disorder caused by a single base substitution of valine for a glutamine at the sixth amino acid of the gene encoding for the hemoglobin β chain. Patients with Hgb SS disease and other sickle hemoglobinopathies suffer from a variety of clinical complications related to this abnormal hemoglobin. These clinical manifestations include hemolytic anemia, painful vaso-occlusive crisis, and end organ damage. Persons with SCD generally auto-splenectomize in childhood secondary to infarctions from their hemoglobinopathy, thus increasing their risk of infection and rendering them immunosuppressed. Data suggest that general immune function in SCD patients may be impaired, and thus responses to vaccine may be suboptimal. Patients with SCD are considered at increased risk of complications from infection from SARS-CoV-2 infection and are therefore an important group to receive vaccination against the virus. Understanding response to COVID-19 vaccination is this high-risk group of patients can provide a more targeted approach to vaccination in order to achieve adequate protection.