Paul Loubet, Ilies Benotmane, Slim Fourati, Florent Malard, Fanny Vuotto, Elodie Blanchard, François Raffi, Stéphanie Nguyen, Nicolas de Prost, Jérôme Avouac
Immunocompromised patients are disproportionately impacted by severe disease, hospitalization, and mortality associated with coronavirus disease 2019 (COVID-19). To optimize the management of these patients in clinical practice, we convened an expert panel to review current evidence on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine responses and severe COVID-19 in immunocompromised populations. We identified four main immunocompromised groups-solid organ transplant recipients, patients receiving allogeneic hematopoietic stem cell transplantation or chimeric antigen receptor (CAR) T cell therapy, patients treated for hematologic malignancies, and patients treated for inflammatory diseases-who mount suboptimal humoral responses to SARS-CoV-2 vaccination and are at increased risk of severe COVID-19-related outcomes. A wide range of risk factors were associated with reduced vaccine responses and/or poor outcomes, most commonly older age, comorbidities, and the type and number of immunosuppressive therapies. We believe that early identification and close monitoring of these at-risk patients, plus regular booster vaccinations, prophylactic monoclonal antibody therapy, non-pharmacologic prevention measures, prompt antiviral treatment, and other risk mitigation strategies, are critical to protect against SARS-CoV-2 infection and severe COVID-19.