Young adults' intention to encourage COVID-19 vaccination among their grandparents: A nationwide cross-sectional survey of college students in China

Background: During a vaccination plateau phase, traditional vaccination promotion strategies such as the mobilization of government and community appear to have limited impact on expanding the coverage. New strategies to promote vaccination are needed especially in older adults. Our study aimed to assess college students' intention to encourage coronavirus disease 2019 (COVID-19) vaccination among their grandparents and its correlates. Methods: A cross-sectional survey was conducted in China from May to June 2022. We collected information on socio-demographics of college students and their grandparents, constructs of health belief model (HBM) and theory of planned behavior (TPB) for college students, and college students' intention to encourage COVID-19 vaccination among their grandparents. Multilevel logistic regression models were performed to assess correlates of intention. Results: We enrolled 2681 college students who reported information for 6302 grandparents. 2272 students (84.7 %) intended to encourage COVID-19 vaccination for 4744 (75.3 %) grandparents. Intention was associated with having received a booster dose of COVID-19 vaccine (AOR 3.28, 95 % CI 1.68-6.42), having ever lived with their grandparents (2.07, 1.46-2.93), and having grandparents who regularly went outdoors (2.85, 1.70-4.76). HBM and TPB models showed that college students who had higher levels of perceived susceptibility (1.79, 1.12-2.87), perceived severity (1.52, 1.12-2.06) of COVID-19 among their grandparents, and higher levels of subjective norms (2.88, 1.61-5.15) were more likely to have the intention. Conclusion: College students' intention to encourage COVID-19 vaccination among their grandparents was high. It may be potentially viable to engage college students in promoting COVID-19 and other routine vaccination among older adults.