Abstract
Introduction: The COVID-19 pandemic has presented significant challenges for immunocompromised populations, particularly hemodialysis patients, who are at an elevated risk for severe outcomes. Vaccination remains a critical strategy to mitigate these risks. This study evaluates the 1-year effectiveness and immunogenicity of the Sinopharm (BBIBP-CorV) COVID-19 vaccine in hemodialysis patients compared to healthy individuals, exploring correlations between dialysis parameters and vaccine-induced immunity.
Methods: This study was conducted according to the ethical principles outlined in the Declaration of Helsinki and approved by the Institutional Review Board of Shahid Beheshti University of Medical Sciences. Participants included 87 hemodialysis patients and 29 healthy controls who received two doses of the Sinopharm vaccine with a 28–30-day interval. Data were collected through in-person interviews and follow-up phone interviews at 2-, 6-, and 12-months post-vaccination. Blood samples were taken at specified intervals to measure humoral and cellular immune responses, including Anti Spike Antibody IgG, Anti receptor-binding domain(RBD) total, neutralizing antibodies, and COVID-19 interferon gamma release assay( IGRA).
Results: A total of 87 hemodialysis patients (68.97% male, mean age 53.32±15.54 years) and 29 healthy controls (27.59% male, mean age 35.72±6.19 years) were included. There was no significant difference in breakthrough infection and its severity among the groups. Breakthrough infections were observed in 5.75% of hemodialysis cases and 17.24% of healthy controls, with hemodialysis not significantly elevating the risk (P=0.08; HR: 0.34; 95% CI: 0.1, 1.16). None of the markers of immune response was associated with breakthrough infection. There was a moderate correlation between Anti-Spike and IGRA level in patients receiving the third dose.
Conclusion: The Sinopharm COVID-19 vaccine demonstrated effectiveness and induced significant immunogenicity in both hemodialysis patients and healthy individuals, with booster doses enhancing long-term immunity. This study underscores the importance of booster vaccinations in maintaining immunity, especially in immunocompromised populations.