Here, we compared the antibody production, CD4 and CD8 T-cell response to the vaccine Spike protein, as well as the neutralization potential of the antibody response in response to two or three doses of SARS-CoV-2 vaccine in 328 subjects including health-care workers (HCW), elderly subjects (>75 yr), and immunocompromised patients with different pathologies either in hemodialysis, with cancer or rheumatological diseases in relation to their treatments. Here, CD4 is linked to cancer.