Replication Data for: Factors Associated With US Adults’ Likelihood of Accepting COVID-19 Vaccination: Evidence From a Survey and Choice-Based Conjoint Analysis

Importance: COVID-19 vaccine development has progressed at unprecedented speed. Widespread public uptake of the vaccine is crucial to stem the pandemic. Objective: To examine the factors associated with survey participants’ self-reported likelihood of selecting and receiving a hypothetical COVID-19 vaccine. Design, Setting and Participants: A survey of a nonprobability convenience sample of 2000 recruited participants including a choice-based conjoint analysis was conducted to estimate respondents’ probability of choosing a vaccine and willingness to receive vaccination . Participants were then asked to evaluate their willingness to receive each vaccine individually. The survey presented respondents with 5 choice tasks. In each, participants evaluated 2 hypothetical COVID-19 vaccines and were asked whether they would choose vaccine A, vaccine B, or neither vaccine . Vaccine attributes included efficacy, protection duration, major side effects, minor side effects, US Food and Drug Administration (FDA) approval process, national origin of vaccine, and endorsement. Levels of each attribute for each vaccine were randomly assigned and attribute order was randomized across participants. Survey data wereas collected on July 9, 2020. Main Outcomes and Measures: Average marginal component effect sizes and marginal means were calculated to estimate the relationship between each vaccine attribute-level and the probability of the respondent choosing a vaccine and self-reported willingness to receive vaccination . Results: A total of 1,971 US adults responded to the survey (median age 43; IQR: 30 to 58); 999 (51%) were women, 1,432 (73%) White, 277 (14%) Black, and 190 (10%) Latinx. An increase in efficacy from 50% to 70% was associated with a higher n increased the estimated probability of choosing a vaccine ofby .07 [95% CI: .06 to .09]; and an increase from 50% to 90% was associated with a higher probability of choosing a vaccine of .16 [95% CI: .15 to .18]. An increase in protection duration from 1 to 5 years was associated with a higher probability of choosing a vaccine of .05 [95% CI: .04 to .07]. A decrease in the incidence of major side effects from 1 in 10,000 to 1 in 1,000,000 was associated with a higher probability of choosing a vaccine of .07 [95% CI: .05 to .08]. An FDA emergency use authorization was associated with a lower probability of choosing a vaccine of -.03 [95% CI: -.01 to -.04] compared with full FDA approval. A vaccine that originated from a non-US country was associated with a lower probability of choosing a vaccine [China: -.13 (95% CI: -.11 to -.15 UK: -.04 (95% CI: -.02 to -.06)]. Endorsements from the US Centers for Disease Control and Prevention [.09 (95% CI: .07 to .11)] and World Health Organization [.06 (95% CI: .04 to .08)], compared with an endorsement from President Trump, were associated with higher probabilities of choosing a vaccine. Analyses of participants’ willingness to receive each vaccine when assessed individually yield similar results. Efficacy was the most important factor. An increase in efficacy from 50% to 90% was associated with a 10% higher marginal mean willingness to receive a vaccine [.51 to .61]. A reduction in the incidence of major side effects was associated with a 4% higher marginal mean willingness to receive a vaccine [.54 to .58]. A vaccine originating in China was associated with a 10% lower willingness to receive a vaccine versus one developed in the US [.60 to .50] Endorsements from the CDC and WHO were associated with substantial increases in willingness to receive a vaccine, 7% and 6%, respectively , from a baseline endorsement by President Trump [.52 to .59; .52 to .58]. Conclusions and Relevance: In this survey study of US adults, vaccine-related attributes and political characteristics were associated with self-reported preferences for choosing a hypothetical COVID-19 vaccine and self-reported willingness to receive vaccination. These results may help inform public health campaigns to address vaccine hesitancy when a COVID-19 vaccine becomes available.

研究背景与意义：新冠疫苗研发进度已达到前所未有的水平。公众广泛接种疫苗对于遏制本次新冠大流行至关重要。
研究目的：探究与调查受访者自我报告的选择并接种假设性新冠疫苗的可能性相关的影响因素。
研究设计、场景与研究对象：本研究针对招募的非概率便利样本开展调查，共纳入2000名受访者，同时采用基于选择的联合分析以估算受访者选择疫苗的概率与接种意愿。随后要求受访者分别评估其对每款疫苗的接种意愿。本次调查为受访者提供5项选择任务，每项任务中受访者需评估2款假设性新冠疫苗，并选择接种疫苗A、疫苗B或均不接种。疫苗属性包括有效性、保护时长、严重不良反应、轻微不良反应、美国食品药品监督管理局（Food and Drug Administration, FDA）审批流程、疫苗原产国以及背书机构。每款疫苗的各项属性水平均为随机分配，且受访者间的属性顺序亦为随机设置。调查数据采集于2020年7月9日。
主要结局与测量指标：本研究计算了平均边际组分效应量与边际均值，以估算每项疫苗属性水平与受访者选择疫苗的概率、自我报告接种意愿之间的关联。
研究结果：共1971名美国成年人参与本次调查（年龄中位数43岁；四分位距：30~58岁）；其中999名（51%）为女性，1432名（73%）为白人，277名（14%）为黑人，190名（10%）为拉丁裔。有效性从50%提升至70%，与选择疫苗的预估概率升高0.07[95%置信区间：0.06~0.09]相关；有效性从50%提升至90%，则与选择疫苗的预估概率升高0.16[95%置信区间：0.15~0.18]相关。保护时长从1年延长至5年，与选择疫苗的预估概率升高0.05[95%置信区间：0.04~0.07]相关。严重不良反应发生率从1/10000降至1/1000000，与选择疫苗的预估概率升高0.07[95%置信区间：0.05~0.08]相关。与获得FDA完全审批相比，获得FDA紧急使用授权与选择疫苗的预估概率降低0.03[95%置信区间：-0.01~-0.04]相关。非美国原产疫苗与选择疫苗的预估概率降低相关[中国产疫苗：-0.13（95%置信区间：-0.11~-0.15）；英国产疫苗：-0.04（95%置信区间：-0.02~-0.06）]。相较于特朗普总统的背书，美国疾病控制与预防中心（Centers for Disease Control and Prevention, CDC）[0.09（95%置信区间：0.07~0.11）]与世界卫生组织（World Health Organization, WHO）[0.06（95%置信区间：0.04~0.08）]的背书均与选择疫苗的预估概率升高相关。
针对受访者单独评估每种疫苗时的接种意愿的分析结果相似。有效性是最重要的影响因素。有效性从50%提升至90%，与接种疫苗的边际均值升高10%[0.51~0.61]相关。严重不良反应发生率降低，与接种疫苗的边际均值升高4%[0.54~0.58]相关。与美国研发的疫苗相比，中国产疫苗与接种意愿降低10%[0.60~0.50]相关。CDC与WHO的背书分别使接种意愿相较于以特朗普总统为背书方的基线水平显著升高7%与6%[0.52~0.59；0.52~0.58]。
研究结论与现实意义：本项针对美国成年人的调查研究显示，疫苗相关属性与政治特征与受访者自我报告的假设性新冠疫苗选择偏好及自我报告的接种意愿相关。本研究结果可为新冠疫苗获批后的公众健康宣传活动提供参考，以应对疫苗犹豫问题。