COVID-19 vaccination uptake, safety, and clinical outcomes among patients on maintenance hemodialysis

Objectives: Patients with end-stage kidney disease (ESKD) on maintenance hemodialysis are extremely vulnerable to severe COVID-19 infection. This prospective observational cohort study aimed to investigate the level of acceptance, determinants of hesitancy, and clinical outcomes of the COVID-19 vaccine among adult ESKD patients on regular hemodialysis in Muscat, Oman. Material and Methods: A prospective observational cohort study was conducted at a renal dialysis unit (RDU) in Muscat, Oman, between December 2020 and May 2021. The study evaluated 74 outpatients on regular hemodialysis from a total unit population of 200. Participants were included if they were ≥18 years old and on maintenance hemodialysis for ≥3 months. They were categorized based on their vaccination status at the time of follow-up. Demographic characteristics, comorbidities, dialysis vintage, vaccine side effects, COVID-19 infection rates, and mortality were analyzed. Data were collected via structured questionnaires and medical record reviews. Results: Among the 74 participants actively evaluated, 44 (60%) were willing to receive the vaccine and completed the two-dose series, while 30 (40%) refused vaccination entirely. The primary reasons for refusal included fear of side effects (43.3%), family refusal (30.1%), and cultural issues (20%). Baseline characteristics, including dialysis vintage, were similar between groups. Following the first dose, 15.9% of vaccinated patients reported adverse events, primarily fever. Across the entire RDU of 200 patients, there were 84 COVID-19 infections resulting in 10 deaths. Within the specific study cohort of 74 patients, 18 contracted COVID-19. Infection rates were 20.5% (9/44) in the vaccinated group and 30.0% (9/30) in the unvaccinated group. Using the vaccinated group as the reference, unvaccinated patients had higher odds of infection (odds ratio = 1.67, 95% confidence interval: 0.57– 4.86), though this was not statistically significant ( p = 0.413). Among the 18 infected study participants, mortality was 77.8% (7/9) in the vaccinated group and 55.6% (5/9) in the unvaccinated group ( p = 0.620). Conclusion: Vaccine hesitancy remains a significant challenge among hemodialysis patients, driven primarily by fear of adverse events and misinformation. While infection rates were numerically lower in vaccinated patients, mortality was higher among vaccinated individuals who contracted the virus, though neither finding reached statistical significance. The small sample size limits the statistical power of this study. Larger prospective studies adjusting for time-at-risk and multiple confounders are necessary to definitively determine vaccine effectiveness in this vulnerable population.