Humoral and cellular immune responses after three or four doses of BNT162b2 in patients with hematological malignancies

Objectives Initial responses to coronavirus disease 2019 vaccination are impaired in patients with hematological malignancies. We investigated immune responses after three or four doses of BNT162b2 in patients with myeloid and lymphoid malignancies compared to controls, and identified risk factors for humoral and cellular nonresponse 1 year after first vaccination. Methods In 407 hematological patients (45 myeloid, 362 lymphoid) and 98 matched controls, we measured immunoglobulin G (IgG) and neutralizing antibodies specific for the receptor‐binding domain of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) at baseline, 3 weeks, 2, 6, and 12 months, and interferon‐γ release at 12 months. Results In patients with lymphoid malignancies, SARS‐CoV‐2 receptor‐binding domain IgG concentration and mean neutralizing capacity was lower than in controls at all time points. A diagnosis of chronic lymphocytic B‐cell leukemia (CLL) or lymphoma was associated with humoral nonresponse at 12 months compared to having multiple myeloma/amyloidosis (p