Abstract
The previous study suggested that the immune response against influenza virus infection after receiving standard-dose influenza vaccines in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) is lower than in the general population. Consequently, we aimed to investigate the post-vaccine immune response in ESRD patients by administering in two dosage regimens of influenza vaccine (double dose and standard dose). Methodology: This research aimed to assess the efficacy of a trivalent influenza vaccine in two doses (double dose vs. standard dose) among ESRD patients undergoing hemodialysis. We collected data from ESRD patients undergoing hemodialysis at two hospitals in Bangkok from April 2021 to April 2022. The patients were randomly divided into three groups: 1) those receiving the standard-dose influenza vaccine, 2) those receiving a high-dose influenza vaccine (double the standard dose), and 3) those receiving a high-dose influenza vaccine (double the standard dose) with an additional booster of the high-dose vaccine six months after the initial dose. Subsequently, patient monitoring included blood tests before vaccination (at month 0) and post-vaccination at months 1, 6, 7, and 12. The study examined the specific hemagglutination inhibition antibody levels that can prevent influenza, with a titer equal to or greater than 1:40 indicating a 50% prevention rate and a titer equal to or greater than 1:160 indicating a 95% prevention rate in individuals with normal immunity. Additionally, the study evaluated the specific cellular immune response using the flow cytometry technique. Results: This study included a total of 84 ESRD patients undergoing hemodialysis, with 28 in Group 1, 30 in Group 2, and 26 in Group 3. The median age of patients receiving hemodialysis was 71 years, and the gender distribution was nearly equal between males and females. In Groups 2 and 3, a higher level of immunity against influenza virus strain A (HI titer 1: ≥ 160) was observed 12 months after vaccination compared to Group 1, approximately 2.5 and 3.7 times higher respectively. However, the assessment for influenza strain B was inconclusive due to predominantly high levels of antibody immunity at month 0 (before vaccination). Regarding the specific cellular immune response, the secretion of cytokines IFN-γ and TNF-α from white blood cells stimulated by influenza viruses of all three strains showed no statistically significant differences across all study groups. The maximum cytokine frequency was observed one month after vaccination (0.36; IQR 0.20 – 0.55), decreasing to 00.36; IQR 0.20 – 0.55 six months after vaccination, the same as pre-vaccination levels. Conclusion: This study discovered that administering the influenza vaccine in either a two-dose or two-dose regimen with a booster six months after the initial shot significantly enhanced humoral immunity against the influenza A virus strain. However, no differences were observed in cellular immune response stimulation. Hence, receiving the two-dose vaccine regimen with a booster at six months after the initial dose might contribute to reducing influenza infections in ESRD patients undergoing dialysis. This insight could potentially serve as a basis for policy recommendations regarding influenza vaccination strategies for this specific population group.
