The related factors for influencing herpes zoster vaccination and willingness among older adults aged ≥60 years in China: A conditional inference tree analysis and traditional logistic regression.

Herpes zoster (HZ) poses a significant health burden on older adults, for whom vaccination (HZV) is the most effective preventive strategy. Despite this, HZV coverage in China remains critically low. This study aimed to identify key determinants of HZV uptake and willingness among urban Chinese older adults using both traditional and machine learning methods. A cross-sectional survey was conducted from December 2024 to January 2025 among adults aged ≥60 y in six major Chinese cities. We collected data on sociodemographics, health status, HZV awareness, and vaccination behavior. Chi-square tests, multivariate logistic regression, and a conditional inference tree model were used for analysis. The overall HZV coverage was only 13.7%. Among vaccinated individuals, awareness of eligibility (OR = 5.623, 95% CI: [4.566, 6.924]) and receiving a physicians' recommendation (OR = 2.342, 95% CI: [1.921, 2.855]) were the most powerful predictors. Other significant factors included regional health insurance policies and educational level (P < .05). For the vast majority who were unvaccinated, high cost was the primary barrier, and willingness to vaccinate was projected to rise to 28.3% if the vaccine were more affordable. HZV coverage among China's urban elderly is alarmingly low, hindered by distinct barriers for different subgroups. While enhancing physicians' recommendation and eligibility awareness is crucial for driving uptake, addressing the financial barrier is paramount to unlocking vaccination willingness among the broader unvaccinated population. A multi-faceted public health strategy targeting both informational and economic barriers is urgently needed to improve HZV coverage.