Abstract
BACKGROUND: Elderly patients with chronic lower respiratory diseases (CLRDs) demonstrate an increased susceptibility to complications arising from influenza. Influenza vaccination remains the most effective strategy against influenza-related diseases among elderly CLRD patients. This study aimed to evaluate the influenza vaccination status of older CLRD patients and the factors affecting influenza vaccination. METHODS: Using population-based health registries, we analyzed the longitudinal uptake of influenza vaccination among elderly patients with CLRDs in Ningbo from the 2018/19 season to the 2022/23 season. A multivariate logistic regression analysis was performed to identify behavioral determinants influencing influenza vaccination among elderly CLRD patients under Ningbo's post-pandemic free vaccination policy. RESULTS: An average of 487,309 older patients with CLRDs were included in our analysis for each season. The influenza vaccination rate increased from 3.59% in 2018/19 to 43.32% in the 2022/23 influenza season. There was a significant increase in the proportion of timely influenza vaccinations prior to November 15, rising from 3.01% before the COVID-19 pandemic to 33.90% during the pandemic period. The multivariate logistic regression analysis indicated that both the COVID-19 pandemic and free vaccination policy significantly promoted influenza vaccine uptake. Older CLRD patients with comorbidities such as diabetes, hypertension, or cancer exhibited higher influenza vaccination coverage, whereas those who have experienced acute cardiovascular events showed a lower vaccination rate. Additionally, a prior vaccination history significantly influenced uptake. CONCLUSIONS: Despite the significant improvement in vaccination rates, coverage among elderly patients with CLRDs remains below the WHO target. Addressing this gap requires integrated interventions that combine expanding the population eligible for free vaccinations, community mobilization efforts, and effective communication regarding cardiovascular safety to mitigate vaccine hesitancy within high-risk groups.