Impaired Immune Response to SARS-CoV-2 Vaccination in Dialysis Patients and in Kidney Transplant Recipients.

Background: Patients with kidney failure on dialysis or after renal transplantation have a high risk for severe COVID-19 infection, and vaccination against SARS-CoV-2 is the only expedient prophylaxis. Generally, immune responses are attenuated in patients with kidney failure, however, systematic analyses of immune responses to SARS-CoV-2 vaccination in patients on dialysis and in kidney transplant recipients (KTRs) are still needed.
Methods: In this prospective, multicentric cohort study, antibody responses to COVID-19 mRNA vaccines (BNT162b2 [BioNTech/Pfizer] or mRNA-1273 [Moderna]) were measured in 32 patients on dialysis and in 28 KTRs. SARS-CoV-2-specific antibodies and neutralization capacity were evaluated and compared with controls ( n =78) of a similar age range.
Results: After the first vaccination, SARS-CoV-2-specific antibodies were nearly undetectable in patients with kidney failure. After the second vaccination, 93% of the controls and 88% of patients on dialysis but only 37% of KTRs developed SARS-CoV-2-specific IgG above cutoff. Moreover, mean IgG levels were significantly lower in KTRs (54±93 BAU/ml) compared with patients on dialysis (503±481 BAU/ml; P <0.01). Both KTRs and patients on dialysis had significantly lower IgG levels compared with controls (1992±2485 BAU/ml; P <0.001 and P <0.01, respectively). Importantly, compared with controls, neutralizing antibody titers were significantly lower in KTRs and patients on dialysis. After the second vaccination, 76% of KTRs did not show any neutralization capacity against SARS-CoV-2, suggesting impaired seroprotection.
Conclusions: Patients with kidney failure show a significantly weaker antibody response compared with controls. Most strikingly, only one out of four KTRs developed neutralizing antibodies against SARS-CoV-2 after two doses of vaccine. These data suggest that vaccination strategies need modification in KTRs and patients on dialysis. Clinical Trial registry name and registration number: Vaccination Against COVID-19 in Chronic Kidney Disease, NCT04743947.
Competing Interests: L.C. Rump reports having consultancy agreements with, and receiving honoraria from, Bayer, Boehringer, Medtronic, and ReCor. M. Schmitz reports receiving honoraria from Daiichi-Sankyo. J. Stegbauer reports having other interests in/relationships with American Heart Association High Blood Pressure, German Society of Nephrology, and German Society of Hypertension; receiving honoraria from AstraZeneca, Bayer Life Science, and Boehringer; serving on the editorial board of Experimental and Clinical Endocrinology & Diabetes and Kidney360; and receiving research funding from German Research Foundation. All remaining authors have nothing to disclose.
(Copyright © 2021 by the American Society of Nephrology.)