inclusion criteria: 1. patients who underwent solid organ transplantation prior to revaccination against covid-19. 2. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. 3. age \> 18 years. 4. all participants must have previously agreed to participate in the study by signing the informed consent form.

inclusion criteria: 1. patients who underwent solid organ transplantation prior to revaccination against covid-19. 2. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. 3. age \> 18 years. 4. all participants must have previously agreed to participate in the study by signing the informed consent form.

inclusion criteria: patients who underwent solid organ transplantation prior to revaccination against covid-19. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. age > 18 years. all participants must have previously agreed to participate in the study by signing the informed consent form.

inclusion criteria: patients who underwent solid organ transplantation prior to revaccination against covid-19. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. age > 18 years. all participants must have previously agreed to participate in the study by signing the informed consent form.

inclusion criteria: 1. patients who underwent solid organ transplantation prior to revaccination against covid-19. 2. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. 3. age > 18 years. 4. all participants must have previously agreed to participate in the study by signing the informed consent form.

inclusion criteria: 1. patients who underwent solid organ transplantation prior to revaccination against covid-19. 2. patients who have received the full covid-19 vaccination regimen with spikevax (moderna) vaccine, with a minimum of 8 weeks having elapsed from the second dose to the time of trial initiation. 3. age > 18 years. 4. all participants must have previously agreed to participate in the study by signing the informed consent form.