An update on SARS-CoV-2 prevention strategy in solid organ transplant recipients: an expert opinion.

Compared to immunocompetent individuals, solid organ transplant recipients (SOTRs) develop a weaker immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination. Although anti-SARS-CoV-2 vaccines can prevent symptomatic and severe disease, the SOTR population remains at risk as long as SARS-CoV-2 continues to circulate. To protect transplanted patients against severe COVID-19, two primary preventive strategies have been proposed: anti-SARS-CoV-2 vaccination and pre-exposure prophylaxis (PrEP) with monoclonal antibodies that possess neutralizing activity against SARS-CoV-2. The effectiveness of vaccination varies depending on the type of organ transplanted and the immunosuppressive therapy used, whereas the effectiveness of PrEP does not depend on these factors. The timing of vaccination and PrEP administration is also crucial. A stronger immune response is observed when vaccination is conducted during the nadir of immunosuppressive therapy. However, when PrEP is administered concomitantly with the vaccine, the efficacy of the vaccination could be reduced, both in terms of antibody production and cell-mediated immunity. Therefore, PrEP should be administered at least 15 days after vaccine administration. In addition to the availability of various preventive measures against COVID-19 for the most vulnerable transplant patients, the scientific community strongly recommends adhering to protective measures, such as wearing masks, practicing hand hygiene, and maintaining social distancing. These expert recommendations offer crucial guidance on preventing SARS-CoV-2 infection in solid organ transplant patients and are applicable to everyday clinical practice.