Cellular and humoral immunogenicity of a SARS-CoV-2 mRNA vaccine in patients on haemodialysis

Background: Patients with chronic renal insufficiency on maintenance haemodialysis face an increased risk of COVID-19 induced mortality and impaired vaccine responses. To date, only a few studies have addressed SARS-CoV-2 vaccine elicited immunity in this immunocompromised population. Methods: We assessed immunogenicity of the mRNA vaccine BNT162b2 in at-risk dialysis patients and characterised systemic cellular and humoral immune responses in serum and saliva using interferon gamma release assay and multiplex-based cytokine and immunoglobulin measurements. We further compared binding capacity and neutralization efficacy of vaccination-induced immunoglobulins against emerging SARS-CoV-2 variants Alpha, Beta, Epsilon and Cluster 5 by ACE2-RBD competition assay. Findings: Patients on maintenance haemodialysis exhibit detectable but variable cellular and humoral immune responses against SARS-CoV-2 and variants of concern after a two-dose regimen of BNT162b2. Although vaccination-induced immunoglobulins were detectable in saliva and plasma, both anti-SARS-CoV-2 IgG and neutralization efficacy was reduced compared to a vaccinated non-dialysed control population. Similarly, T-cell mediated interferon gamma release after stimulation with SARS-CoV-2 spike peptides was significantly diminished. Interpretation: Quantifiable humoral and cellular immune responses after BNT162b2 vaccination in individuals on maintenance haemodialysis are encouraging, but urge for longitudinal follow-up to assess longevity of immunity. Diminished virus neutralization and interferon gamma responses in the face of emerging variants of concern may favour this at-risk population for re-vaccination using modified vaccines at the earliest opportunity. (C) 2021 The Authors. Published by Elsevier B.V.

Automated summary

Patients on maintenance haemodialysis show detectable but variable cellular and humoral immune responses to SARS-CoV-2 and variants of concern after receiving the BNT162b2 vaccine. While encouraging, the diminished virus neutralization and interferon gamma responses in the face of emerging variants may indicate a need for re-vaccination using modified vaccines in this at-risk population.