The emergence of SARS-CoV-2 Omicron variant has led to a complete reconfiguration of the therapeutic landscape, with most monoclonal antibodies having lost any neutralization activity. We report here a case series of 75 immunocompromised patients infected by the Omicron variant who benefited of convalescent plasma. At baseline, 49 (68%) of the participants had a WHO score of 5 and 23 (32%) a WHO score of 6. At day 28 the case fatality was 24%. We observed no significant difference in the clinical outcome between patients with hematological malignancies, solid organ transplantation or auto-immune diseases. These promising results require controlled studies.