Cellular and humoral immunogenicity of the mRNA-1273 SARS-CoV-2 vaccine in patients with hematologic malignancies.

Recent studies have demonstrated a suboptimal humoral response to SARS-CoV-2 mRNA vaccines in patients diagnosed with hematologic malignancies, however data about cellular immunogenicity is scarce. In this study we aimed to evaluate both the humoral and cellular immunogenicity one month after the second dose of the mRNA-1273 vaccine. Antibody titers were measured by the Elecsys and LIAISON Anti-SARS-CoV-2 S assay while T-cell response was assessed by Interferon-Gamma-Release-immuno-Assay technology. Overall, 76.3% (184/241) of patients developed humoral immunity and the cellular response rate was 79% (184/233). Hypogammaglobulinemia, lymphopenia, active hematological treatment and anti-CD20 therapy during the last 6 months were associated with an inferior humoral response. Conversely, age over 65 years, active disease, lymphopenia and immunosuppressive treatment for GvHD were associated with an impaired cellular response. A significant dissociation between humoral and cellular response was observed in patients treated with anti-CD20 therapy, being the humoral response of 17.5% whereas the cellular response was 71.1%. In these patients B-cell aplasia was confirmed while T cell counts were preserved. In contrast, humoral response was observed in 77.3% of patients under immunosuppressive treatment for GvHD, while only 52.4% had cellular response. The cellular and humoral response to the SARS-CoV-2 mRNA-1273 vaccine in patients with hematological malignancies is highly influenced by the presence of treatments like anti-CD20 therapy and immunosuppressive agents. This observation has implications for the further management of these patients.