Annual influenza vaccination reduces total hospitalization in patients with chronic hepatitis B virus infection: A population-based analysis

Background: This study evaluated hospitalization and mortality in patients with chronic hepatitis B virus infection (HBV (+)) and matched comparison patients after stratifying the patients according to annual influenza vaccination (Vaccine (+)). Methods: Data from Taiwan's National Health Insurance program from 2000 to 2009 were used to identify HBV(+)/vaccine(+) (n=4434), HBV(+)/Vaccine(-) (n=3646), HBV(-)/Vaccine(+) (n=8868), and HBV(-)/Vaccine(-) (n=8868) cohorts. The risk of pneumonia/influenza, respiratory failure, intensive care, hospitalization, and mortality in the four cohorts was evaluated. Results: The total hospitalization rate was significantly lower in patients with chronic HBV infection who received an annual influenza vaccination than in chronic HBV-infected patients who did not receive an influenza vaccination (16.29 vs. 24.02 per 100 person-years), contributing to an adjusted hazard ratio (HR) of 0.56 (95% confidence interval (CI). =0.50-0.62). The HBV(+)/Vaccine(+) cohort also had lower risks than the HBV(+)/Vaccine(-) cohort for pneumonia and influenza (adjusted HR. =0.79, 95% CI. =0.67-0.92), intensive care unit admission (adjusted HR. =0.33, 95% CI. =0.25-0.43), and mortality (adjusted HR. =0.19, 95% CI. =0.15-0.24). Conclusions: Our results suggest that annual influenza vaccination can reduce the risk of hospitalization and mortality in patients with chronic HBV infection.