A Phase 4 interventional study of Reduction in antimetabolite immunosuppression in COVID-19, Immunosuppression and Vaccine Response Impaired, sponsored by University of California, Davis. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by University of California, Davis · Phase 4, Interventional, and Prevention
Immunocompromised individuals, such as solid organ transplant (SOT) recipients are at high risk of COVID-19 associated complications and mortality. Retrospective studies so far have shown that a majority of SOT recipients did not develop appreciable anti-spike antibody response after a first, second, or even third dose of mRNA vaccine. Treatment with antimetabolites was associated with poor vaccine response. The goal of this study is 1) examine whether transient immunosuppression reduction improves the immune response to a third dose of SARS-CoV-2 mRNA vaccine in kidney transplant recipients and 2) to assess the safety of immunosuppression reduction before and after third dose SARS-CoV-2 mRNA vaccination.
This is a prospective, randomized open-labeled study of kidney transplant recipients who have previously received two doses of mRNA COVID-19 vaccine (either BNT162b2, Pfizer-BioNTech or mRNA-1273, Moderna) and who are eligible to receive a 3rd dose of mRNA vaccine.
7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.
This study's enrollment of 14 is below the median of 100 across 4,099 interventional studies indexed under COVID-19.
Browse COVID-19 studies →University of California, Davis is the lead sponsor of 798 studies on the registry; 146 are open to participants now.
Of its 65 completed or terminated interventional studies of FDA-regulated products, 43 (66%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Reduction of immunosuppression before and after administration of a third dose of SARS-CoV-2 mRNA vaccine
Drug: Reduction in antimetabolite immunosuppression
No change to immunosuppression before or after receipt of a third dose of SARS-Co-2 mRNA vaccine
Reduction in dose in mycophenolate mofetil/mycophenolic acid (MMF) or azathioprine before and after receiving 3rd dose vaccination
Change in anti-SARS-CoV-2 IgG titer to SARS-CoV-2 target proteins from baseline
Time frame: 6 weeks after receipt of 3rd dose mRNA vaccine
Percentage of participants who achieve high-positive antibody titer
Time frame: 6 weeks after receipt of 3rd dose mRNA vaccine
Acute rejection
Time frame: 1 week to 16 weeks after intervention
De Novo donor specific antibody (DSA) development
Time frame: 4 week to 16 weeks after intervention
Change in donor-derived cell free DNA from baseline
Time frame: 1 week to 16 weeks after intervention
Change in glomerular filtration rate (GFR) from baseline
Time frame: 1 week to 16 weeks after intervention
Change in proteinuria from baseline
Time frame: 1 week to 16 weeks after intervention
Plan to share: No
This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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University of California, Davis