Antibody and T-Cell Responses against SARS-CoV-2 after Booster Vaccination in Patients on Dialysis: A Prospective Observational Study

Intensive vaccination is recommended for populations more vulnerable to COVID-19 infection, although data regarding the built of immunity after vaccination for dialysis patients are lacking. This prospective, observational cohort study of maintenance hemodialysis patients examined IgG antibody levels against the SARS-CoV-2 spike (S1) protein, neutralizing activity, and interferon gamma levels after the third dose of the BNT162b2 (Pfizer–BioNTech) or mRNA-1273 (Moderna) vaccine. Humoral immunity was repeatedly measured for up to two months. The study includes 58 patients on hemodialysis. Median neutralizing antibodies reached a maximum at 56 and 9 days after booster vaccination with BNT162b2 and mRNA-1273, respectively. The median IgG antibody titer reached a maximum of 3104.38 and 7209.13 AU/mL after 16 days of booster dose, and cellular immunity was positive in 61.9% and 100% of patients with BNT162b2 and mRNA-1273 vaccination, respectively. By repeating the measurements over a period of two months, we clarified the chronological aspects of the acquisition of humoral immunity in dialysis patients after a booster COVID-19 vaccination; most dialysis patients acquired not only humoral immunity, but also cellular immunity against SARS-CoV-2. Future research should investigate the continued long-term dynamics of antibody titers and cellular immunity after the third or further vaccinations, evaluating the need for additional vaccinations for hemodialysis patients.