Immunosuppressed persons are a heterogeneous population that represents approximately 3 % of the adult population. They are more vulnerable to infectious agents, such as SARS-CoV-2. This is reflected by a reduced response to vaccination, a higher rate of progression towards a severe form of the disease, and recurrent or persistent infections associated with intra-host viral evolution. This review summarizes the evidence regarding vaccine efficacy, clinical and virological singularities, and the management in immunosuppressed patients.