In this study, we sought to investigate the vaccine response in a group of individuals with immunodeficiency in terms of interferon-gamma (IFN-γ) production using a whole-blood assay to spike protein and peptide (S, S1, S+) mix stimulation, in addition to spike protein-specific antibody levels post primary COVID-19 vaccination and booster vaccines. The gene discussed is CHMP5; the disease is COVID-19.