Abstract
Background: Coronavirus disease 2019 (COVID-19) is associated with increased morbidity and mortality in chronic kidney disease patients, especially those on maintenance hemodialysis (HD). The comparison of immunogenicity of different COVID vaccines in the dialysis populations is lacking especially in the middle east region.
Methods: We conducted a retrospective observational study, that includes 164 hemodialysis patients (HD) and 54 health workers (HW), who received 2 doses of either Pfizer-BioNTech or Sinopharm vaccine. The primary endpoint was to report the rate of seroconversion and the factors affecting it.
Results: HD patients have a significantly low seroconversion rate than HW (HD vs HW: 76.54% and 100%, p=<0.05), also S1 IgG antibody level was significantly low in HD patients (HD vs HW: 183.5 and 400 BAU/ml, p=<0.05). The type of vaccine and hypo-response to the HBV vaccine were two statistically significant factors affecting the seropositivity rate in HD patients. As compared to Sinopharm, Pfizer-BioNTech vaccinated HD patients exhibit not only higher seroconversion rate (Pfizer-BioNTech vs Sinopharm: 90.80% and 60%, p=<0.05) but also express high S1 antibody titer (Pfizer-BioNTech vs Sinopharm: 425 and 162 BAU/ml (p=<0.05), however, there is no significant difference in post-vaccine COVID infection rate among the two vaccines (Pfizer-BioNTech vs Sinopharm: 39.24% and 42.22% (p= 0.176).
Conclusion: Lower Immune response to the COVID vaccine is observed in HD patients as compared to HW participants, also Pfizer-BioNTech vaccinated HD patients exhibit better seroconversion rates and higher antibody titer than Sinopharm vaccine in HD patients, so alternative vaccine strategies should be designed in dialysis patients.