ABSTRACT
Background: From March to May of the current year, the Department of onco-hematology of “Guglielmo da Saliceto” hospital of Piacenza vaccinated 108 haematological patients with a m-RNA vaccine, either Pfizer- BionNTech or Moderna. The aim of this study is to investigate the efficacy and safety of COVID-19 vaccine Materials and methods: This is an observational study. We analyzed the humoral immune response by antibody titer (IgG) at baseline (T0) and 4-6 weeks after the first dose of vaccine (T1). We evaluated whether age, sex, hematologic disease, previous bone marrow transplant, past COVID-19 infection and antitumor treatments interfere with the development of the humoral immune response evaluated with an anti-SARS-CoV-2 IgG ChemiLuminescent ImmunoAssay (LIAISON SARS-CoV2 S1/S2 IgGDIASORIN Inc.) measured in AU/ml. An antibody level 315 AU/ml was considered relevant. Results: From the 108 patients enrolled, 87 patients with median age of 65 years (IQR 58-71) have T1 IgG determination available of which 51 patients (58,62%) seroconverted, with IgG median value of 254 AU/ml (IQR 98,1-385 AU/ml), whereas 36 patients (41,38%) did not, with IgG median value of 3.8 AU/ml (IQR 3.8-4,5 AU/ml). Being on active anticancer treatment at the time of vaccination (p 0,03), especially on anti-CD20 monoclonal therapy (p 0.001), showed a statistically significant effect on seroconversion in univariate analysis, while age over 60 years and sex (male vs female) are near to be significant (respectively p 0.05 and p 0.06). Hematologic disease and previous bone marrow transplant (without differentiate between allo-HSCT and auto-HSCT) seem not to influence the immune response. In multivariate analysis, only anti-CD20 monoclonal therapy deeply reduces the probability of seroconversion (99,97%, p 0.003). The latter does not seem to be influenced by age, sex and active therapy (including all the remaining immunomodulant or immunosuppressor treatments). None of the patients had adverse reactions to vaccine, neither allergic nor immunological. Conclusions: More than half of the patients seroconverted. Active antitumor therapy, especially anti-CD20 monoclonal antibody, seems to have a negative effect on seroconversion. We are actually testing the cell-mediated immune response to prove the efficacy of COVID vaccination also in those immunocompromised subjects who did not seroconverted. The m-RNA vaccines seem to be safe in patients with immune deficiency.