The main objective of this trial is to evaluate the immunogenicity of reimmunization against SARS-CoV-2 in patients undergoing solid organ transplantation with heterologous revaccination, testing whether in patients who received two doses of Spikevax Moderna vaccine there is a significant increase at 28 days in their antibody titers against SARS-CoV-2 after receiving a dose of Janssen.~The secondary objectives of this trial are:~To evaluate the efficacy of reimmunization against SARS-CoV-2 in subjects undergoing solid organ transplantation, in terms of incidence of infection and severity of COVID-19 after revaccination in the transplanted patient.~To gain insight into the humoral and cellular immune response conferred by the sequential combination of both homologous and heterologous vaccination over one year, as well as its duration in subjects undergoing solid organ transplantation.~To evaluate the safety of vaccines against SARS-CoV-2 in subjects undergoing solid organ transplantation.~To determine the potential existence of differences in humoral (Anti S Ac) and cellular immune response depending on the immunosuppression regimen.~To evaluate the occurrence of side effects, including rejection and anti-HLA and DSA antibodies after revaccination.
Patients undergoing solid organ transplantation randomly selected from those who have received two doses of Spikevax (Moderna) vaccine, provided that a minimum of 8 weeks have elapsed from the second dose to the time of the start of the trial. It is planned to include 386 patients.