Publication date: May 26, 2025
Background: Kidney transplant (KTx) recipients exhibit impaired responses to SARS-CoV-2 vaccination. Correlates of vaccine-induced immunity and risk factors for breakthrough infection are not fully defined. This study evaluated the humoral response trajectories and determinants of breakthrough infection in KTx recipients. Methods: KTx recipients received two doses of the BNT162b2 mRNA vaccine three weeks apart and a booster after six months. Patients were categorized based on pre-vaccination status: previous COVID-19 disease (DIS), asymptomatic SARS-CoV-2 infection (INF), or infection-nacEFve (NEG). Serum anti-spike antibody titers were assessed at baseline, before the second dose, and at 1, 3, 6, 9, and 12 months. Linear mixed models and survival analyses were performed. Results: Of 326 enrolled patients, 189 with complete time-point data were included in the longitudinal analysis. Antibodies were detectable in 89% of DIS/INF at baseline and 91% before the second dose, but were negligible in NEG. In NEG, the seropositivity increased after vaccination and booster, reaching 78% at 12 months. Age (-5% per year, p < 0. 001) and BMI (+10% per unit, p = 0. 004) influenced titers; antimetabolites and steroids had strong negative effects (-70%, p = 0. 005; -84%, p = 0. 001). Breakthrough infections occurred in 104 (31. 9%); 40% were asymptomatic, and 2 patients died. An mTOR inhibitor was associated with a reduced infection risk (OR 0. 27 [CI: 0. 09-0. 70], p = 0. 009). Higher antibody titers correlated with delayed infection (p = 0. 063). Conclusions: In KTx patients, humoral response to SARS-CoV-2 vaccination is limited in infection-nacEFve patients but improved by booster dosing; the hybrid immunity is more effective. Immunosuppressive regimens influence the immune response, and mTOR inhibitors may protect against breakthrough infection.
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| Concepts | Keywords |
|---|---|
| Antimetabolites | BNT162b2 |
| Bnt162b2 | COVID |
| Months | hybrid immunity |
| Transplant | immune response |
| Vaccination | infection risk |
| kidney transplant | |
| mRNA vaccine | |
| SARS-CoV-2 |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | Breakthrough Infection |
| disease | MESH | COVID-19 |
| pathway | REACTOME | SARS-CoV-2 Infection |
| disease | MESH | infection |
| disease | IDO | immune response |
| disease | MESH | hepatitis |
| disease | MESH | diabetes mellitus |
| disease | MESH | hypertension |
| disease | MESH | cardiovascular diseases |
| disease | MESH | lung disease |
| disease | MESH | obesity |
| disease | IDO | susceptibility |
| disease | MESH | virus infections |
| disease | MESH | cancers |
| disease | MESH | seroconversion |
| disease | MESH | respiratory failure |
| disease | IDO | hospital facility |
| disease | IDO | blood |
| disease | IDO | assay |
| disease | IDO | history |
| drug | DRUGBANK | Methionine |
| disease | MESH | Kidney disease |
| disease | MESH | Glomerulonephritis |
| disease | MESH | Diabetic nephropathy |
| disease | MESH | Immune diseases |
| disease | MESH | ADPKD |
| disease | MESH | reinfection |
| disease | MESH | tics |