This is an observational non-interventional study in cancer patients. The study will evaluate the safety, tolerability and immunogenicity of Pfizer SARS-CoV-2 RNA vaccine against COronaVIrus Disease-19 (COVID-19) which will be delivered in the deltoid muscle in 2-dose (separated by 21 days). Blood will be collected in two 5 milliliters (mL) vacuettes for serum Immunoglobulin G (IgG) and Cytokine assessment, at baseline and after 21 days, immediately before the first and the second dose, respectively, then after 42 days from the first dose and finally after 6 months from the baseline. A panel of 22 cytokines (Biorad) will be measured at baseline and after 21 and 42 days in four groups consisting of: no responders (S1/S2 IgG\<15 Arbitrary Unit AU/ml at 42 days), slow responders (S1/S2 IgG\<15 AU/mL after 21 days and \>15 AU/mL after the second dose), fast responders (S1/S2 IgG\>15 AU/mL after the first 21 days) and immunized patients (S1/S2 IgG\>15 AU/mL at baseline). At baseline, at 42 days and 6 months questionnaires for psychological testing will be dispensed for completion to patients.
After 42 days from the first dose, 15 mL of heparinized peripheral blood from both non-responders (S1/S2 IgG\<25 AU/mL) and responders will be used for isolation of different Cluster of Differentiation 4 (CD4+) and CD8+ T cell subpopulations and analysis of their capability to undergo activation/proliferation in response to specific SARS- CoV-2 derived peptides.
