Pham Gam H, Tran Quang V, Bui Hiep T, Nguyen Thoai D, Vo Trung Q, Jedsadayanmata Arom, Huynh Bon H, Sholihat Nia K
Faculty of Pharmacy, Pham Ngoc Thach University of Medicine, Ho Chi Minh, Vietnam.
Faculty of Pharmacy, Thammasat University, Bangkok, Thailand.
Narra J. 2025 Apr;5(1):e1107. doi: 10.52225/narra.v5i1.1107. Epub 2025 Jan 1.
The rising threat of emerging infectious diseases (EIDs) highlights the need to understand factors influencing vaccine adoption. The aim of this study was to explore the willingness to vaccinate and vaccine acceptance preferences among Millennials and Generation Z in Vietnam. Convenience sampling was conducted, after which a traditional discrete choice experiment was performed. Participants were tasked with selecting their preferred options from a set of eight vaccination choice tasks, each consisting of two alternatives distinguished by varying degrees of vaccine efficacy, side effects, influential endorsements, trusted sources, and disease susceptibility through literature reviews, expert interviews, and pilot tests. A minimum sample size of 375 participants was recruited via Internet- based and paper-based surveys. A latent class model was used to explore the heterogeneity in participant preferences, while a mixed logit model was employed to facilitate the computation of the predicted probabilities of vaccine acceptance. Among the 818 included participants, 494 (60.4%) were Millennials generation. The predicted probability of vaccine acceptance was 61.8%, with slight differences between Millennials (62.4%) and Generation Z (61.0%). Four latent classes with significant preference variations were identified. Class 1 (38%) was influenced by vaccine effectiveness, side effects, and health authority recommendations, showing lower opt-out rates. Class 2 (28%) prioritized vaccine effectiveness and authority recommendations but had higher opt-out rates and a stronger religious influence. Class 3 (23%) focused on vaccine effectiveness and side effects, with a tendency to opt-out. Class 4 (11%) valued high vaccine effectiveness and advice from family, with infection risks to family or local areas being significant motivators. Influential voices were more important in Classes 1 and 2, while side effects and effectiveness were prioritized in Classes 3 and 4. In conclusion, Vietnamese Millennials and Generation Z preferred vaccination when the vaccine had 90% efficacy, mild to moderate side effects, endorsements from the Ministry of Health, positive recommendations from family and social networks, and high exposure risks from family members.
新发传染病（EIDs）日益增长的威胁凸显了了解影响疫苗接种因素的必要性。本研究的目的是探讨越南千禧一代和Z世代的疫苗接种意愿及疫苗接受偏好。采用便利抽样法，之后进行传统的离散选择实验。参与者的任务是从一组八个疫苗接种选择任务中选择他们偏好的选项，每个任务包含两个备选方案，这些备选方案通过文献综述、专家访谈和预试验，在疫苗效力、副作用、有影响力的支持、可信来源以及疾病易感性方面存在不同程度的差异。通过基于网络和纸质的调查招募了至少375名参与者。使用潜在类别模型探索参与者偏好的异质性，同时采用混合逻辑模型来计算疫苗接受的预测概率。在纳入的818名参与者中，494名（60.4%）为千禧一代。疫苗接受的预测概率为61.8%，千禧一代（62.4%）和Z世代（61.0%）之间略有差异。识别出四个偏好差异显著的潜在类别。第1类（38%）受疫苗效力、副作用和卫生当局建议的影响，退出率较低。第2类（28%）优先考虑疫苗效力和当局建议，但退出率较高且宗教影响较强。第3类（23%）关注疫苗效力和副作用，有退出倾向。第4类（11%）重视高疫苗效力和家人的建议，家人或当地的感染风险是重要的推动因素。有影响力的声音在第1类和第2类中更重要，而第3类和第4类则优先考虑副作用和效力。总之，当疫苗效力达90%、副作用为轻至中度、有卫生部的支持、家人和社交网络的积极推荐以及家庭成员有高暴露风险时，越南的千禧一代和Z世代更倾向于接种疫苗。
