ABSTRACT
This prospective study evaluated seroconversion rates in response to BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine booster in 44 B-cell non-Hodgkin lymphoma (B-NHL) patients who failed to respond to two prior doses [42 previously exposed to anti-CD20 monoclonal antibodies (moAbs) including 13 under maintenance treatment]. Seroconversion was obtained in 29.5% of the patients. Longer time from last anti-CD20 moAb (>6 months) and diagnosis of aggressive lymphoma compared to other, incurable B-NHLs were associated with increased seroconversion rates (47.8% vs.10.5%, p = 0.019 and 50% vs. 17.9%, p = 0.025 respectively). Thus, seronegative patients with B-NHL that completed anti-CD20 therapy more than 6 months prior to the booster have greater chances to achieve seroconversion.