A snapshot of the immunogenicity, efficacy and safety of a full course of BNT162b2 anti-SARS-CoV-2 vaccine in cancer patients treated with PD-1/PD-L1 inhibitors: a longitudinal cohort study.

Background Very few cancer patients were enrolled in coronavirus disease-2019 vaccine studies. In order to address this gap of knowledge, real-world studies are mandatory. The aim of this study was to assess both humoral and cellular response after a messenger RNA vaccination schedule. Patients and methods Eighty-eight consecutive cancer patients treated with programmed cell death protein 1/programmed death-ligand 1 inhibitors were enrolled from the beginning of the vaccination campaign for frail patients. Blood samples for humoral and cell-mediated immune response evaluation were obtained before vaccination (T0), before the second administration (T1) and 21 days after the second dose (T2). The primary endpoint was the evaluation of the percentage of participants showing a significant increase in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells, measured by an enzyme-linked immunospot assay, after the second dose of BNT162b2 vaccine. The proportion of patients who reached the primary endpoint is computed together with its exact binomial 95% confidence interval. Results In SARS-CoV-2-naive subjects, spike-specific T-cell response was almost undetectable at T0 [median 0.0 interferon-γ (IFN-γ) spot forming units (SFU)/million peripheral blood mononuclear cell (PBMC) interquartile range (IQR) 0-7.5] and significantly increased at T1 and T2 (median 15.0 IFN-γ SFU/million PBMC, 25th-75th 0-40 versus 90 IFN-γ SFU/million PBMC, 25th-75th 32.5-224, respectively) (P Conclusions Our data have demonstrated that the administration of a full course of BNT162b2 vaccine elicited a sustained immune response against SARS-CoV-2 regardless of the type of cancer and/or the type of immune checkpoint inhibitors.