Prevalence of SARS-CoV-2 Cellular and Humoral Immunity Amongst Patients on Dialysis After the First Vaccination Campaign

Background: Immunisation remains critical in prevention of serious COVID-19 infection. This study aimed to characterise the prevalence of humoral and cellular immunity in patients on maintenance dialysis in a nephrology centre 8 months after vaccination onset. Methods: Real-world single-centre prevalence cross-sectional study enrolling patients on peritoneal and haemodialysis. Humoral response was measured as specific IgG (anti-spike protein receptor-binding domain IgG) and cellular response as T cell reactivity through interferon γ quantification as response to antigen. Results: Of the 86 patients enrolled, 79.4% and 84.1% showed humoral and cellular immunity, respectively. Anti-spike protein receptor-binding domain IgG correlated with specific T cell reactivity (ρ=0.58; p<0.001). Vaccinated patients with associated high comorbidity burden and low serum albumin were at risk of absent immunity (p<0.05). Conclusion: The prevalence of humoral and cellular immunity against severe acute respiratory syndrome coronavirus 2 in vaccinated Portuguese patients on maintenance dialysis is high. High comorbidity burden and low serum albumin are risk factors for absent immune response.