Breakthrough infection after SARS-CoV-2 vaccines in patients with hemoglobinopathies and blood-transfusion management: a single Center experience

Abstract

Purpose Immune system impairment is frequently reported in patients affected by hemoglobinopathies due to various mechanisms, including iron accumulation, antigenic stimulation due to numerous transfusions, chronic hemolysis, and a hyperinflammatory state. The antigenic immune response after a vaccine could be ineffective. Methods We evaluated the anti-spike IgG production after 2 doses of vaccine for SARS-CoV-2 in patients affected by hemoglobinopathies, reporting the risk of breakthrough infections, monitoring the outcome and the risk of severe disease or complications related to the basal hematological disease. Results All 114 enrolled patients developed adequate antibody production, with a median value of serum anti-S IgG of 2184.4 BAU/mL. The amount of antibody was unrelated to any other clinical characteristics evaluated, including transfusion dependence, age, gender, disease type, ferritin, blood count, spleen status, and therapy with hydroxyurea or iron chelators (p > 0.05). Moreover, 47 (41.2%) patients developed breakthrough SARS-CoV-2 infection during the follow-up, all with a mildly symptomatic course, without requiring hospitalization or experiencing a significative drop in hemoglobin values, allowing for a slight delay in their transfusion regimen. Conclusion Vaccination has been an effective and safe tool in this category of patients, preventing severe complications. Watchful waiting in the transfusion strategy can be safely ensured, guaranteeing better management of transfusion components.