Association Between Influenza Vaccination and Reduced Risk of Acute
Kidney Injury Among the Elderly
Abstract
Background: Several cases of renal complications including
acute kidney injury (AKI) after influenza vaccination have been
reported, but the association remains unproven. We evaluated the
association between influenza vaccination and AKI occurrence among the
Korean elderly in the 2018–2019 and 2019–2020 seasons.
Methods: We used a large database that combined vaccination
registration data from the Korea Disease Control and Prevention Agency
and the claims data from the National Health Insurance Service. The
study subjects were patients hospitalized with AKI for the first time
following vaccination among those who received one influenza vaccine in
the 2018–2019 or 2019–2020 season. Only those who were 65 or older at
the date of vaccination were included in our study. We performed a
self-controlled case series study in which the risk period was
designated as 1 to 28 days after vaccination, and the observation period
as each influenza season. We conducted sensitivity analyses with varied
risk periods and observation periods. Results: A total of
16,713 and 16,272 AKI events were identified during each influenza
season. The adjusted incidence rate ratio (aIRR) for AKI was 0.83 (95%
confidence interval [CI]= 0.79–0.87) in the 2018–2019 season. The
IRR of the 2019–2020 influenza vaccination was similar to the
2018–2019 season (aIRR=0.86; 95% CI=0.82–0.90). Sensitivity analyses
showed similar results. Conclusions: We suggest that influenza
vaccination is associated with a lower risk of AKI in the elderly over
65.