Humoral response to BNT162b2 mRNA COVID-19 vaccine in peritoneal and hemodialysis patients: A comparative study

Introduction Maintenance dialysis patients (MDP) are at higher risk of exposure with increased mortality from COVID-19 with generalized immunization becoming the cornerstone in prevention. This study aims to compare humoral response between hemodialysis (HD) and peritoneal dialysis (PD) patients. Materials and Methods Observational prospective study following HD and PD programs from a Portuguese Center receiving BNT162b2 vaccine. Specific anti-Spike IgG quantification to compare both for absolute value and non-responders (NR) between modalities and against risk factors. Results Of 67 MDP, 42 were HD and 25 PD patients. PD developed higher antibody titers after both first (median 5.44 vs. 0.99 AU/ml, p < 0.01) and second dose (median 170.43 vs. 65.81 AU/ml; p < 0.01). HD associated with NR after the first dose (p < 0.01). Conclusion This study demonstrated improved humoral immunogenicity with BNT162b2 in PD compared to HD patients. These differences are attributed to comorbidity burden and age differences, rather than dialysis modality.