Pilot Trial on Immunosuppression Modulation to Increase SARS-CoV-2 Vaccine Response in Kidney Transplant Recipients

Inclusion Criteria: * Patient has received a kidney transplantation * \> 18 years of age * No SARS-CoV-2 spike protein antibodies four weeks after at least three previous vaccine doses * Maintenance immunosuppression with mycophenolate or azathioprine Exclusion Criteria: * acute illness with fever * Prior documented infection with SARS-CoV-2 * triple anticoagulation therapy * Subject is currently enrolled in or has not yet completed at least 30 days since ending other investigational device or drug trial(s), or subject is receiving other investigational agent(s) * Subject has known sensitivity or intolerance to any of the products to be administered for the purpose of this study * Subject has any kind of disorder that compromises the ability of the subject to give written informed consent and/or to comply with the study procedures * Subject is pregnant or breast feeding * SARS-CoV-2 spike protein antibodies four weeks after the 3rd last vaccination \> 0.8 BAU/mL