Impact of an interactive web tool on patients' intention to receive COVID-19 vaccination: a before-and-after impact study among patients with chronic conditions in France

Effectiveness of chatbots on COVID vaccine confidence and acceptance in Thailand, Hong Kong, and Singapore

Chatbots have become an increasingly popular tool in the field of health services and communications. Despite chatbots' significance amid the COVID-19 pandemic, few studies have performed a rigorous evaluation of the effectiveness of chatbots in improving vaccine confidence and acceptance. In Thailand, Hong Kong, and Singapore, from February 11th to June 30th, 2022, we conducted multisite randomised controlled trials (RCT) on 2,045 adult guardians of children and seniors who were unvaccinated or had delayed vaccinations. After a week of using COVID-19 vaccine chatbots, the differences in vaccine confidence and acceptance were compared between the intervention and control groups. Compared to non-users, fewer chatbot users reported decreased confidence in vaccine effectiveness in the Thailand child group [Intervention: 4.3 % vs. Control: 17%, P = 0.023]. However, more chatbot users reported decreased vaccine acceptance [26% vs. 12%, P = 0.028] in Hong Kong child group and decreased vaccine confidence in safety [29% vs. 10%, P = 0.041] in Singapore child group. There was no statistically significant change in vaccine confidence or acceptance in the Hong Kong senior group. Employing the RE-AIM framework, process evaluation indicated strong acceptance and implementation support for vaccine chatbots from stakeholders, with high levels of sustainability and scalability. This multisite, parallel RCT study on vaccine chatbots found mixed success in improving vaccine confidence and acceptance among unvaccinated Asian subpopulations. Further studies that link chatbot usage and real-world vaccine uptake are needed to augment evidence for employing vaccine chatbots to advance vaccine confidence and acceptance.

Effect of a mobile app chatbot and an interactive small-group webinar on COVID-19 vaccine intention and confidence in Japan: a randomised controlled trial

INTRODUCTION

We investigated the effect of social media-based interventions on COVID-19 vaccine intention (VI) and confidence in Japan.

METHODS

We conducted a three-arm randomised controlled trial between 5 November 2021 and 9 January 2022 during a low incidence (<1000/day) of COVID-19 in Japan in the midst of the second and the third waves. Japanese citizens aged ≥20 who had not received any COVID-19 vaccine and did not intend to be vaccinated were randomly assigned to one of the following three groups: (1) a control group, (2) a group using a mobile app chatbot providing information on COVID-19 vaccines and (3) a group using interactive webinars with health professionals. VI and predefined Vaccine Confidence Index (VCI) measuring confidence in the importance, safety and effectiveness were compared before and after the interventions under intention-to-treat principle. Logistic regression models were used to investigate the effect of each intervention on postintervention VI and changes of VCI compared with control.

RESULTS

Among 386 participants in each group, 359 (93.0%), 231 (59.8%) and 207 (53.6%) completed the postsurvey for the control, chatbot and webinar groups, respectively. The average duration between the intervention and the postsurvey was 32 days in chatbot group and 27 days in webinar group. VI increased from 0% to 18.5% (95% CI 14.5%, 22.5%) in control group, 15.4% (95% CI 10.8%, 20.1%) in chatbot group and 19.7% (95% CI 14.5%, 24.9%) in webinar group without significant difference (OR for improvement=0.8 (95% CI 0.5, 1.3), p=0.33 between chatbot and control, OR=1.1 (95% CI 0.7, 1.6), p=0.73 between webinar and control). VCI change tended to be larger in chatbot group compared with control group without significant difference (3.3% vs -2.5% in importance, OR for improvement=1.3 (95% CI 0.9, 2.0), p=0.18; 2.5% vs 1.9% in safety, OR=1.1 (95% CI 0.7, 1.9), p=0.62; -2.4% vs -7.6% in effectiveness, OR=1.4 (95% CI 0.9, 2.1), p=0.09). Improvement in VCI was larger in webinar group compared with control group for importance (7.8% vs -2.5%, OR=1.8 (95% CI 1.2, 2.8), p<0.01), effectiveness (6.4% vs -7.6%, OR=2.2 (95% CI 1.4, 3.4), p<0.01) and safety (6.0% vs 1.9%, OR=1.6 (95% CI 1.0, 2.6), p=0.08).

CONCLUSION

This study demonstrated that neither the chatbot nor the webinar changed VI importantly compared with control. Interactive webinars could be an effective tool to change vaccine confidence. Further study is needed to identify risk factors associated with decreased vaccine confidence and investigate what intervention can increase VI and vaccine confidence for COVID-19 vaccines.

TRIAL REGISTRATION NUMBER

UMIN000045747.

Interventions to increase COVID-19 vaccine uptake: a scoping review

BACKGROUND

Vaccines are effective in preventing severe COVID-19, a disease for which few treatments are available and which can lead to disability or death. Widespread vaccination against COVID-19 may help protect those not yet able to get vaccinated. In addition, new and vaccine-resistant mutations of SARS-CoV-2 may be less likely to develop if the spread of COVID-19 is limited. Different vaccines are now widely available in many settings. However, vaccine hesitancy is a serious threat to the goal of nationwide vaccination in many countries and poses a substantial threat to population health. This scoping review maps interventions aimed at increasing COVID-19 vaccine uptake and decreasing COVID-19 vaccine hesitancy.

OBJECTIVES

To scope the existing research landscape on interventions to enhance the willingness of different populations to be vaccinated against COVID-19, increase COVID-19 vaccine uptake, or decrease COVID-19 vaccine hesitancy, and to map the evidence according to addressed populations and intervention categories.

SEARCH METHODS

We searched Cochrane COVID-19 Study Register, Web of Science (Science Citation Index Expanded and Emerging Sources Citation Index), WHO COVID-19 Global literature on coronavirus disease, PsycINFO, and CINAHL to 11 October 2021.

SELECTION CRITERIA

We included studies that assess the impact of interventions implemented to enhance the willingness of different populations to be vaccinated against COVID-19, increase vaccine uptake, or decrease COVID-19 vaccine hesitancy. We included randomised controlled trials (RCTs), non-randomised studies of intervention (NRSIs), observational studies and case studies with more than 100 participants. Furthermore, we included systematic reviews and meta-analyses. We did not limit the scope of the review to a specific population or to specific outcomes assessed. We excluded interventions addressing hesitancy towards vaccines for diseases other than COVID-19.

DATA COLLECTION AND ANALYSIS

Data were analysed according to a protocol uploaded to the Open Science Framework. We used an interactive scoping map to visualise the results of our scoping review. We mapped the identified interventions according to pre-specified intervention categories, that were adapted to better fit the evidence. The intervention categories were: communication interventions, policy interventions, educational interventions, incentives (both financial and non-financial), interventions to improve access, and multidimensional interventions. The study outcomes were also included in the mapping. Furthermore, we mapped the country in which the study was conducted, the addressed population, and whether the design was randomised-controlled or not.

MAIN RESULTS

We included 96 studies in the scoping review, 35 of which are ongoing and 61 studies with published results. We did not identify any relevant systematic reviews. For an overview, please see the interactive scoping map (https://tinyurl.com/2p9jmx24) STUDIES WITH PUBLISHED RESULTS Of the 61 studies with published results, 46 studies were RCTs and 15 NRSIs. The interventions investigated in the studies were heterogeneous with most studies testing communication strategies to enhance COVID-19 vaccine uptake. Most studies assessed the willingness to get vaccinated as an outcome. The majority of studies were conducted in English-speaking high-income countries. Moreover, most studies investigated digital interventions in an online setting. Populations that were addressed were diverse. For example, studies targeted healthcare workers, ethnic minorities in the USA, students, soldiers, at-risk patients, or the general population.  ONGOING STUDIES Of the 35 ongoing studies, 29 studies are RCTs and six NRSIs. Educational and communication interventions were the most used types of interventions. The majority of ongoing studies plan to assess vaccine uptake as an outcome. Again, the majority of studies are being conducted in English-speaking high-income countries. In contrast to the studies with published results, most ongoing studies will not be conducted online. Addressed populations range from minority populations in the USA to healthcare workers or students. Eleven ongoing studies have estimated completion dates in 2022.   AUTHORS' CONCLUSIONS: We were able to identify and map a variety of heterogeneous interventions for increasing COVID-19 vaccine uptake or decreasing vaccine hesitancy. Our results demonstrate that this is an active field of research with 61 published studies and 35 studies still ongoing. This review gives a comprehensive overview of interventions to increase COVID-19 vaccine uptake and can be the foundation for subsequent systematic reviews on the effectiveness of interventions to increase COVID-19 vaccine uptake.  A research gap was shown for studies conducted in low and middle-income countries and studies investigating policy interventions and improved access, as well as for interventions addressing children and adolescents. As COVID-19 vaccines become more widely available, these populations and interventions should not be neglected in research.

AUTHORS CONCLUSIONS

We were able to identify and map a variety of heterogeneous interventions for increasing COVID-19 vaccine uptake or decreasing vaccine hesitancy. Our results demonstrate that this is an active field of research with 61 published studies and 35 studies still ongoing. This review gives a comprehensive overview of interventions to increase COVID-19 vaccine uptake and can be the foundation for subsequent systematic reviews on the effectiveness of interventions to increase COVID-19 vaccine uptake.  A research gap was shown for studies conducted in low and middle-income countries and studies investigating policy interventions and improved access, as well as for interventions addressing children and adolescents. As COVID-19 vaccines become more widely available, these populations and interventions should not be neglected in research.

Using Behavioral Science to Address COVID-19 Vaccine Hesitancy Among Cancer Survivors: Communication Strategies and Research Opportunities

Due to cancer survivors’ increased vulnerability to complications from COVID-19, addressing vaccine hesitancy and improving vaccine uptake among this population is a public health priority. However, several factors may complicate efforts to increase vaccine confidence in this population, including the underrepresentation of cancer patients in COVID-19 vaccine trials and distinct recommendations for vaccine administration and timing for certain subgroups of survivors. Evidence suggests vaccine communication efforts targeting survivors could benefit from strategies that consider factors such as social norms, risk perceptions, and trust. However, additional behavioral research is needed to help the clinical and public health community better understand, and more effectively respond to, drivers of vaccine hesitancy among survivors and ensure optimal protection against COVID-19 for this at-risk population. Knowledge generated by this research could also have an impact beyond the current COVID-19 pandemic by informing future vaccination efforts and communication with cancer survivors more broadly.

Risk-benefit analysis of the AstraZeneca COVID-19 vaccine in Australia using a Bayesian network modelling framework

Thrombosis and Thrombocytopenia Syndrome (TTS) has been associated with the AstraZencea (AZ) COVID-19 vaccine (Vaxzevria). Australia has reported low TTS incidence of < 3/100,000 after the first dose, with case fatality rate (CFR) of 5-6%. Risk-benefit analysis of vaccination has been challenging because of rapidly evolving data, changing levels of transmission, and variation in rates of TTS, COVID-19, and CFR between age groups. We aim to optimise risk-benefit analysis by developing a model that enables inputs to be updated rapidly as evidence evolves. A Bayesian network was used to integrate local and international data, government reports, published literature and expert opinion. The model estimates probabilities of outcomes under different scenarios of age, sex, low/medium/high transmission (0.05%/0.45%/5.76% of population infected over 6 months), SARS-CoV-2 variant, vaccine doses, and vaccine effectiveness. We used the model to compare estimated deaths from AZ vaccine-associated TTS with i) COVID-19 deaths prevented under different scenarios, and ii) deaths from COVID-19 related atypical severe blood clots (cerebral venous sinus thrombosis & portal vein thrombosis). For a million people aged ≥ 70 years where 70% received first dose and 35% received two doses, our model estimated < 1 death from TTS, 25 deaths prevented under low transmission, and > 3000 deaths prevented under high transmission. Risks versus benefits varied significantly between age groups and transmission levels. Under high transmission, deaths prevented by AZ vaccine far exceed deaths from TTS (by 8 to > 4500 times depending on age). Probability of dying from COVID-related atypical severe blood clots was 58-126 times higher (depending on age and sex) than dying from TTS. To our knowledge, this is the first example of the use of Bayesian networks for risk-benefit analysis for a COVID-19 vaccine. The model can be rapidly updated to incorporate new data, adapted for other countries, extended to other outcomes (e.g., severe disease), or used for other vaccines.