Abstract
Background: It is recommended that dialysis patients receive an annual influenza vaccination. However, immune dysregulation in dialysis patients could diminish vaccine response. We sought to evaluate the humoral immune response (HIR) and safety of a standard-dose versus double-dose trivalent inactivated influenza vaccine (trivalent-IIV) in patients on peritoneal dialysis (PD). Method: We conducted a multicenter, randomized, single-blinded, controlled trial at the Ramathibodi Hospital and Banphaeo General Hospital during July 2022 and January 2023. One-hundred PD patients were randomly assigned to a standard-dose (15 mcg of hemagglutinin per strain) or double-dose (30 mcg of hemagglutinin per strain) trivalent-IIV. The reference group included 25 healthy subjects who received a standard-dose trivalent-IIV. The HIR was evaluated at baseline and 4 weeks after vaccination. The primary outcome was the seroprotection rate against each influenza strain, defined as hemagglutination inhibition titers ≥ 1:40. Result: At 1 month after vaccination, all groups exhibited a significant increase in HI titer against all influenza strains compared to baseline (p ≤ 0.05 for all). PD patients who received a double-dose trivalent-IIV had a comparable seroprotection rate for all influenza strains compared to those who received a standard-dose trivalent-IIV for all three influenza strains A/H1N1 (46.2% vs. 52.0%, p = 0.55 and 15.8% vs. 12.5%, p = 0.73; 1 and 6 months respectively) A/H3N2 (69.1% vs. 64.0%, p = 0.69 and 0% vs. 0%, p = 1.00; 1 and 6 months respectively) and Influenza B (51.4% vs. 52.0%, p > 0.99 and 23.1% vs. 27.2%, p = 0.75; 1 and 6 months respectively). Compared to healthy subjects, PD patients could achieve similar seroprotection rate against all influenza strains. Adverse effects were similar in all groups. Subgroup analysis found no statistically significant correlation with immune stimulation for age, sex, white blood cell count, duration of kidney replacement therapy, and co-existing diabetes mellitus. High body mass index had a low correlation with reduced immune stimulation levels. Conclusion: Standard-dose trivalent-IIV could generate similar seroprotection against influenza viruses in PD patients compared to double-dose trivalent-IIV.