Abstract
Background: This study investigated the humoral responses to SARS-CoV-2 in hemodialysis (HD) patients. The clearance of molecules in the blood during hemodialysis is influenced by factors such as filter pore size, flow rate, operating pressure, and treatment duration. Chronic kidney disease patients often show low antibody titers for pathogens like pneumococcus, influenza virus, and hepatitis B virus. Methods: In this study, the surrogate virus neutralization test (sVNT) for the wild type (WT) and Omicron variants, as well as spike-specific IgG levels, were measured at two time points (May 2022 and December 2023). Medical records and questionnaires were used to gather participant information. Results: A total of 26 HD patients were enrolled, including 3 on immunosuppressive therapies. A total of 8 patients had COVID-19 during the first sampling, and 19 during the second. The results showed that sVNT levels for WT decreased over time, though positivity remained at 100% during both sampling periods. In contrast, sVNT levels for Omicron increased significantly, with positivity rising from 46.2% to 75.0% (p < 0.05). Spike-specific IgG levels also increased, with positivity improving from 96.2% to 100%. Patients on immunosuppressive therapies had significantly lower sVNT levels for both WT and Omicron in the second period (p < 0.05), though no significant differences were observed during the first period. Conclusion: HD patients, particularly those on immunosuppressive therapies, showed reduced and declining neutralizing responses over time. A meta-analysis of HD patients seems necessary to determine whether all dialysis patients need COVID-19 booster vaccinations, similar to the hepatitis B vaccine, highlighting the need for targeted vaccination strategies.