TY - JOUR AU - Luk, Tzu Tsun AU - Lui, Judy Hiu Tung AU - Wang, Man Ping PY - 2022 DA - 2022/10/4 TI - Efficacy, Usability, and Acceptability of a Chatbot for Promoting COVID-19 Vaccination in Unvaccinated or Booster-Hesitant Young Adults: Pre-Post Pilot Study JO - J Med Internet Res SP - e39063 VL - 24 IS - 10 KW - COVID-19 KW - coronavirus KW - vaccine KW - immunization KW - booster KW - vaccine hesitancy KW - chatbot KW - conversational agent KW - virtual assistant KW - Chinese KW - young adult KW - youth KW - health promotion KW - health intervention KW - chatbot usability KW - pandemic KW - booster hesitancy KW - web-based survey KW - students KW - university students AB - Background: COVID-19 vaccines are highly effective in preventing severe disease and death but are underused. Interventions to address COVID-19 vaccine hesitancy are paramount to reducing the burden of COVID-19. Objective: We aimed to evaluate the preliminary efficacy, usability, and acceptability of a chatbot for promoting COVID-19 vaccination and examine the factors associated with COVID-19 vaccine hesitancy. Methods: In November 2021, we conducted a pre-post pilot study to evaluate “Vac Chat, Fact Check,” a web-based chatbot for promoting COVID-19 vaccination. We conducted a web-based survey (N=290) on COVID-19 vaccination at a university in Hong Kong. A subset of 46 participants who were either unvaccinated (n=22) or were vaccinated but hesitant to receive boosters (n=24) were selected and given access to the chatbot for a 7-day trial period. The chatbot provided information about COVID-19 vaccination (eg, efficacy and common side effects), debunked common myths about the vaccine, and included a decision aid for selecting vaccine platforms (inactivated and mRNA vaccines). The main efficacy outcome was changes in the COVID-19 Vaccine Hesitancy Scale (VHS) score (range 9-45) from preintervention (web-based survey) to postintervention (immediately posttrial). Other efficacy outcomes included changes in intention to vaccinate or receive boosters and willingness to encourage others to vaccinate on a scale from 1 (not at all) to 5 (very). Usability was assessed by the System Usability Scale (range 0-100). Linear regression was used to examine the factors associated with COVID-19 VHS scores in all survey respondents. Results: The mean (SD) age of all survey respondents was 21.4 (6.3) years, and 61% (177/290) of respondents were female. Higher eHealth literacy (B=–0.26; P<.001) and perceived danger of COVID-19 (B=–0.17; P=.009) were associated with lower COVID-19 vaccine hesitancy, adjusting for age, sex, chronic disease status, previous flu vaccination, and perceived susceptibility to COVID-19. The main efficacy outcome of COVID-19 VHS score significantly decreased from 28.6 (preintervention) to 24.5 (postintervention), with a mean difference of –4.2 (P<.001) and an effect size (Cohen d) of 0.94. The intention to vaccinate increased from 3.0 to 3.9 (P<.001) in unvaccinated participants, whereas the intention to receive boosters increased from 1.9 to 2.8 (P<.001) in booster-hesitant participants. Willingness to encourage others to vaccinate increased from 2.7 to 3.0 (P=.04). At postintervention, the median (IQR) System Usability Scale score was 72.5 (65-77.5), whereas the median (IQR) recommendation score was 7 (6-8) on a scale from 0 to 10. In a post hoc 4-month follow-up, 82% (18/22) of initially unvaccinated participants reported having received the COVID-19 vaccine, whereas 29% (7/24) of booster-hesitant participants received boosters. Conclusions: This pilot study provided initial evidence to support the efficacy, usability, and acceptability of a chatbot for promoting COVID-19 vaccination in young adults who were unvaccinated or booster-hesitant. SN - 1438-8871 UR - https://www.jmir.org/2022/10/e39063 UR - https://doi.org/10.2196/39063 UR - http://www.ncbi.nlm.nih.gov/pubmed/36179132 DO - 10.2196/39063 ID - info:doi/10.2196/39063 ER -