Understanding Drivers of Vaccine Hesitancy During the COVID-19 Pandemic Among Older Adults in Jiangsu Province, China: Cross-sectional Survey - Liuqing Yang; Lili Ji; Qiang Wang; Guoping Yang; Shixin Xiu; Tingting Cui; Naiyang Shi; Lin Zhu; Xuepeng Xu; Hui Jin; Shiqi Zhen (JMIR Formative Research, 2023)