Do Messages Matter? Investigating the Combined Effects of Framing, Outcome Uncertainty, and Number Format on COVID-19 Vaccination Attitudes and Intention

Using Short-Form Videos to Get Clinical Trial Newcomers to Sign Up: Message-Testing Experiment

BACKGROUND

Recruiting participants for clinical trials poses challenges. Major barriers to participation include psychological factors (eg, fear and mistrust) and logistical constraints (eg, transportation, cost, and scheduling). The strategic design of clinical trial messaging can help overcome these barriers. While strategic communication can be done through various channels (eg, recruitment advertisements), health care providers on the internet have been found to be key sources for communicating clinical trial information to US adults in the social media era.

OBJECTIVE

This study aims to examine how communication source (ie, medical doctors and peers) and message framing of TikTok videos (ie, psychological and logistical framing) influence clinical trial-related attitudes, perceptions, and sign-up behaviors under the guidance of the integrated behavioral model.

METHODS

This study used a 2 (source: doctor vs peer) × 2 (framing: psychological vs logistical) between-participant factorial design web-based experiment targeting adults in the United States who had never participated in clinical trials (ie, newcomers). A Qualtrics panel was used to recruit and compensate the study respondents (n=561). Participants viewed short-form videos with doctors or peers, using psychological or logistical framing. The main outcome measures included perceived source credibility, self-efficacy, attitude toward clinical trial participation, behavioral intention, and sign-up behavior. Structural equation modeling was used to analyze the direct and indirect effects of message factors on the outcome variables. Source (doctor=1; peer=0) and framing (psychological=1; logistical=0) were dummy-coded.

RESULTS

Doctor-featured messages led to greater perceived source credibility (β=.31, P<.001), leading to greater self-efficacy (95% CI 0.13-0.30), which in turn enhanced behavioral intention (95% CI 0.12-0.29) and clinical trial sign-up behavior (95% CI 0.02-0.04). Logistical barrier-framed messages led to greater self-efficacy (β=-.09, P=.02), resulting in higher intention to participate in clinical trials (95% CI -0.38 to -0.03) and improved sign-up behavior (95% CI -0.06 to -0.004). Logistical barrier-framed messages were also directly associated with an increased likelihood of signing up for a clinical trial (β=-.08, P=.03). The model accounted for 21% of the variance in clinical trial sign-up behavior. Attitude did not significantly affect behavioral intention in this study (β=.08, P=.14), and psychological and logistical barrier-framed messages did not significantly differ in attitudes toward clinical trial participation (β=-.04, P=.09).

CONCLUSIONS

These findings advance our understanding of how people process popular message characteristics in short-form videos and lend practical guidance for communicators. We encourage medical professionals to consider short-form video sites (eg, TikTok and Instagram Reels) as effective tools for discussing clinical trials and participation opportunities. Specifically, featuring doctors discussing efforts to reduce logistical barriers is recommended. Our measuring of actual behavior as an outcome is a rare and noteworthy contribution to this research.

Motivating COVID-19 Vaccination through Persuasive Communication: A Systematic Review of Randomized Controlled Trials

Vaccination is a vital defense against COVID-19 infections and outbreaks, yet vaccine hesitancy poses a significant threat to pandemic response and recovery. We conducted a systematic review of published randomized controlled trials (N = 47) assessing the persuasive effects of COVID-19 communication on COVID-19 vaccine acceptance. Individual vs. collective appeals and gain vs. loss frames are among the most frequently assessed message features, but they generally do not make a difference in persuasion. Normative messages that highlight higher (vs. lower) prevalence of vaccine acceptance are more persuasive. Message sources overall have limited impact on COVID-19 vaccine acceptance, but sources that have a shared identity with the message receivers tend to be persuasive. More engaging message channels such as interactive chatbots and videos are promising communication tools but are generally under-utilized and under-studied. Compared to no communication or irrelevant communication, COVID-19 vaccine messages generally have a small advantage in increasing COVID-19 vaccine acceptance. Messages that include 1) vaccine safety and/or efficacy information; 2) collective appeals combined with embarrassment appeals; and 3) political leaders' vaccine endorsement are among the most effective messaging strategies. There is no evidence of any backfire effects of COVID-19 vaccine messages. We discuss the implications of our findings for persuasive message design in pandemic vaccine communication.

Message Effectiveness of Fear Appeals in Vaccination Communication Campaigns: A Systematic Review

This systematic review of 54 cross-disciplinary peer-reviewed causal empirical studies helps public health officials, researchers, and healthcare professionals better comprehend the effects of fear appeals in vaccine promotional campaigns on message processing, persuasion, vaccination attitudes, and vaccination intentions. This review documents inconsistent findings across studies, which it attempts to clarify by considering differences in research designs, sample populations, and outcomes measured. In general, we find that fear appeals increase risk perceptions, message involvement, and vaccination attitudes. However, fear appeals have less influence on vaccination intentions, especially among female and general adult populations or populations from the U.S. and other Western cultures. On the other hand, the effect of fear appeals on vaccination intentions is stronger among student populations and those from China (People's Republic of China and Hong Kong) and other non-Western cultures. Also, fear appeals are less persuasive when promoting COVID-19 vaccines and boosters than they are for other vaccines (e.g., HPV, influenza, MMR). Future research should compare fear appeal effectiveness in messages across vaccines or when combined with other executional elements, such as the endorser or type of evidence provided. Finally, future studies should explore other methodological approaches and measure underexplored message outcomes, such as vaccine uptake behavior, in more naturalistic settings.

Communication Strategies to Promote COVID-19 Vaccination Intention: How Effective are Source, Appeal, Framing, and Evidence Type Approaches?

This systematic review analyzed the effectiveness of key persuasive strategies - source, appeal, framing, and evidence (SAFE) - on COVID-19 vaccination intention. Quantitative studies were searched in Web of Science, Scopus, and PubMed following the PRISMA guidelines. From the 61 studies that met inclusion criteria, source and framing are the most commonly applied SAFE strategies. However, source characteristics are a more consistent influence on vaccine intentions than message framing strategies, with expert sources and general practitioners emerging as the key sources contributing to greater vaccine intentions. In addition, a range of mediators and moderators influence the process through which SAFE message strategies impact vaccine intentions. Framing effects, in particular, are moderated by political identity, source characteristics, and vaccine perceptions. Tests of mediating processes highlight how health behavior judgments (e.g. perceived vaccine benefits, risks, trust in vaccination, perceived severity) and message response/perceptions (e.g. counterarguing, perceived similarity/empathy) operate as key intervening factors between SAFE message strategies and vaccine intentions. Overall, when practitioners apply various structural approaches (narrative elements, fear appeals, framing cues) to vaccine promotion campaigns, they should be cognizant of who is providing that appeal. Targeted populations may benefit most from different structural elements if they are integrated with sources that resonate with the audience.

"Trust Me, I'm a Doctor." How TikTok Videos from Different Sources Influence Clinical Trial Participation

This study experiments with TikTok videos to promote clinical trial participation. More specifically, it examines how short-form video sources (doctors vs. prior volunteers for clinical trials) influence perceived source credibility, self-efficacy, and behavioral intention to participate in clinical trials. Findings from this online experiment (N = 396) showed that doctor sources led to greater behavioral intention through enhancing source credibility compared to prior volunteer sources. Alternatively, prior volunteer sources increased behavioral intention via enhanced self-efficacy for participants with low trust in doctors. These findings contribute to the understanding of how short-form video sources act as heuristic cues, leading to persuasion outcomes. Overall, we recommend featuring doctors when using video-based messages to promote clinical trial participation. Also, this study emphasizes the need for health communication practitioners to consider prior volunteers as spokespersons when targeting populations with low baseline trust in doctors.

Communicating uncertainties regarding COVID-19 vaccination: Moderating roles of trust in science, government, and society

This study examined how uncertainty affects information seeking and avoidance behaviors via information insufficiency in the COVID-19 vaccination context. It also investigated how trust in science, government, and society moderate the effects of information insufficiency. An online experiment with 131 Korean adults showed that uncertainty indirectly affects information seeking intentions via information insufficiency, which is moderated by science trust and governmental trust. It also showed that uncertainty indirectly affects information avoidance intentions via information insufficiency, which is moderated by social trust.

I want to be safe: understanding the main drivers behind vaccination choice throughout the pandemic

BACKGROUND

Despite being a major advancement in modern medicine, vaccines face widespread hesitancy and refusal, posing challenges to immunization campaigns. The COVID-19 pandemic accentuated vaccine hesitancy, emphasizing the pivotal role of beliefs in efficacy and safety on vaccine acceptance rates. This study explores the influence of efficacy and safety perceptions on vaccine uptake in Italy during the pandemic.

METHODS

We administered a 70-item questionnaire to a representative sample of 600 Italian speakers. Participants were tasked with assessing the perceived effectiveness and safety of each vaccine dose, along with providing reasons influencing their vaccination choices. Additionally, we conducted an experimental manipulation, exploring the effects of four framing messages that emphasized safety and/or efficacy on participants' willingness to receive a hypothetical fourth vaccine dose. Furthermore, participants were asked about their level of trust in the scientific community and public authorities, as well as their use of different information channels for obtaining COVID-19-related information.

RESULTS

Our study reveals a dynamic shift in vaccine efficacy and safety perceptions throughout the COVID-19 pandemic, potentially influencing vaccination compliance. Initially perceived as more effective than safe, this assessment reversed by the time of the third dose. Beliefs regarding safety, rather than efficacy, played a significant role in anticipating future vaccinations (e.g., the booster dose). Safety-focused messages positively affected vaccination intent, while efficacy-focused messages showed limited impact. We also observed a changing trend in reasons for vaccination, with a decline in infection-related reasons and an increase in social related ones. Furthermore, trust dynamics evolved differently for public authorities and the scientific community.

CONCLUSIONS

Vaccine perception is a dynamic process shaped by evolving factors like efficacy and safety perceptions, trust levels, and individual motivations. Our study sheds light on the complex dynamics that underlie the perception of vaccine safety and efficacy, and their impact on willingness to vaccinate. We discuss these results in light of bounded rationality, loss aversion and classic utility theory.

Effects of COVID-19 vaccine safety framing on parental reactions

As a major concern shared by parents globally, COVID-19 vaccine safety is typically being messaged to the public in a negative frame in many countries. However, whether the COVID-19 vaccine safety framing have an effect on parents when vaccinating their children is unclear. Here we implement an online survey with a convenience sample of 3,861 parents living in mainland China, all over 18 years old and with at least one child under 18. The parents were randomly assigned to receive information about COVID-19 vaccine safety in either a negative frame (incidence of side effects) or a positive frame (the inverse incidence of side effects), to compare parental reactions to a range of questions about communication, risk perception, trust, involvement and behavioral intention. We found that parents were more likely to regard vaccine safety as relevant to policy support and as a higher priority for government when receiving positively framed information (p = 0.002). For some specific subgroups, parents in positive framing group showed lower risk perception and higher trust (p<0.05). This suggests that positive framing of COVID-19 vaccine safety messages show more effective performance than negative framing in terms of involvement, as well as trust and risk perception in specific subgroups, which may lead to a reflection on whether to adjust the current widespread use of negative framing. Our findings inform how governments and health care workers strategically choose the framing design of COVID-19 vaccine safety information, and have important implications for promoting COVID-19 vaccination in children in the future.

Exploring the Strategic Use of TikTok for Clinical Trial Recruitment: How audiences' Prior Short-Form Video Usage Influences Persuasive Effects

Guided by the elaboration likelihood model and framing theory, this study explores the potential of short-form video platforms (e.g. TikTok), for targeted clinical trial recruitment. An online experiment compared doctor vs. peer-led videos addressing logistical or psychological barriers to participation, mimicking common TikTok communication tactics. Results indicate that high (vs. low) TikTok users are more persuaded by recruitment messages, and they exhibit stronger intentions to participate in clinical trials. Although doctor-sourced messages generate greater credibility and a more favorable message attitude, peer-sourced messages may be more effective in increasing participation intention. Lastly, doctor-sourced videos that address logistical barriers and peer-sourced videos that discuss psychological barriers result in higher self-efficacy for clinical trial participation. This study contributes to the growing body of research on new media's role in health communication and provides insights into how to strategically utilize TikTok and other short-form video platforms for clinical trial recruitment.

A study on the factors influencing the intention to receive booster shots of the COVID-19 vaccine in China based on the information frame effect

Introduction

In the response to and prevention and control of the Novel coronavirus pneumonia, the COVID-19 vaccine does not provide lifelong immunity, and it is therefore important to increase the rate of booster shots of the COVID-19 vaccine. In the field of information health science, research has found that information frames have an impact in changing individual attitudes and health behaviors.

Objective

This study focuses on the effects of different influencing factors on the public's willingness to receive the booster shots of the COVID-19 vaccine under two information frameworks.

Methods

An online questionnaire was conducted to explore the effects of demographic characteristics, personal awareness, social relationships, risk disclosure, perceived booster vaccination protection rate, and duration of protection under the assumption of an information framework. T test and one-way analysis were used to testing the effect of variables.

Results

(1) The persuasion effect under the gain frame is higher than that under the loss frame (B = 0.863 vs. B = 0.746); (2) There was no significant difference in subjects' intention of booster vaccination in terms of gender, age, income, occupation, educational background and place of residence. Whether family members received booster vaccination was strongly correlated with their intention of vaccination under the loss framework (p = 0.017, M = 4.63, SD = 0.664). (3) The higher the understanding of COVID-19, the higher the degree of compliance with the government's COVID-19 prevention and control measures, and the higher the willingness to strengthen vaccination; (4) Risk disclosure has a significant impact on people's willingness to receive COVID-19 booster shots (M = 2.48, under the loss framework; M = 2.44, under the gain framework); (5) Vaccine protection rate and duration of protection have an impact on people's willingness to vaccinate. Increased willingness to vaccinate when the protection rate of booster vaccine approaches 90% (M = 4.76, under the loss framework; M = 4.68, under the gain framework). When the vaccine protection period is 2 years, people are more willing to receive a booster vaccine; and the willingness to receive a booster shot is stronger under the loss framework (M = 4.60, SD = 0.721, p = 0.879).

Conclusion

The impact of the information framework on COVID-19 vaccination intentions is different, and the disclosure of relevant health information should focus on the impact of the information framework and content on the public's behavior toward strengthening vaccination. Therefore, in the face of public health emergencies, public health departments, healthcare institutions, and other sectors can consider adopting the Gainful Information Framework tool to disseminate health information to achieve better persuasion and promote public health behavior change enhancing public health awareness, and promoting universal vaccination.

COVID-19 Vaccination Coverage and Associated Factors in Patients with Multiple Sclerosis

Our objective was to know the COVID-19 vaccination coverage in multiple sclerosis (MS) patients and its factors associated. A retrospective cohort study was carried out. Patients seen at the MS unit of the University Clinical Hospital of Zaragoza between 2017 and 2021 were included. Variables were obtained by reviewing the specialized and primary care records. Associations between receiving COVID-19 full primo-vaccination, as well as one booster dose since autumn 2022, and the other variables were analyzed using bivariate analysis and multiple logistic regression models. Of the 359 included patients, 90.3% received the COVID-19 full primo-vaccination. Having been born in Spain (aOR = 3.40) and having received the 2020-2021 influenza vaccine (aOR = 6.77) were associated with receiving the COVID-19 full primo-vaccination. Vaccination with a COVID-19 booster dose was detected in 141 patients (39.3%). Sex (man) (aOR = 2.36), age (60 years or over) (aOR = 6.82), type of MS (Primary Progressive/Secondary Progressive) (aOR = 3.94), and having received the 2022-2023 influenza vaccine (aOR = 27.54) were associated with receiving such a booster dose. The COVID-19 booster dose was administered at the same time as the 2022-2023 influenza vaccine in 57.8% (67/116) of the patients vaccinated with both vaccines. The COVID-19 full primo-vaccination coverage is higher than in other countries. However, the decrease in vaccination coverage with the booster dose makes it necessary to develop strategies to improve it that are not limited to administering the flu vaccine together with the COVID-19 booster dose. Such strategies should be in focus, especially for women under 60 years of age.

How Mortality Salience and Self-Construal Make a Difference: An Online Experiment to Test Perception of Importance of COVID-19 Vaccines in China

To better understand why Chinese residents' COVID-19 perceptions of the importance of vaccination change dramatically over time, this research used an online lab-like experiment to test the antecedents of individuals' perception of the importance of COVID-19 vaccines. We find that participants who view themselves as separate from others (i.e. independent self-construal) perceive COVID-19 vaccines as more important than Hepatitis B vaccines (i.e. control group), regardless of how salient mortality is for them. In contrast, among participants who view themselves as a part of their social groups (i.e. interdependent self-construal), awareness of death (i.e. mortality salience) plays a moderating role. Specifically, when mortality is salient, COVID-19 vaccines are considered more important than Hepatitis B vaccines; when morality is not salient, vaccine type does not make a difference on perceptions of vaccine importance.

The impact of side effect framing on COVID-19 booster vaccine intentions in an Australian sample

OBJECTIVE

To evaluate the effect of presenting positively attribute-framed side effect information on COVID-19 booster vaccine intention relative to standard negatively-framed wording and a no-intervention control.

DESIGN AND PARTICIPANTS

A representative sample of Australian adults (N = 1204) were randomised to one of six conditions within a factorial design: Framing (Positive; Negative; Control) × Vaccine (Familiar (Pfizer); Unfamiliar (Moderna)).

INTERVENTION

Negative Framing involved presenting the likelihood of experiencing side effects (e.g., heart inflammation is very rare, 1 in every 80,000 will be affected), whereas Positive Framing involved presenting the same information but as the likelihood of not experiencing side effects (e.g., 79,999 in every 80,000 will not be affected).

PRIMARY OUTCOME

Booster vaccine intention measured pre- and post-intervention.

RESULTS

Participants were more familiar with the Pfizer vaccine (t(1203) = 28.63, p <.001, Cohen's d_z = 0.83). Positive Framing (M = 75.7, SE = 0.9, 95% CI = [73.9, 77.4]) increased vaccine intention relative to Negative Framing (M = 70.7, SE = 0.9, 95% CI = [68.9, 72.4]) overall (F(1, 1192) = 4.68, p =.031, η_p² = 0.004). Framing interacted with Vaccine and Baseline Intention (F(2, 1192) = 6.18, p =.002, η_p² = 0.01). Positive Framing was superior, or at least equal, to Negative Framing and Control at increasing Booster Intention, irrespective of participants' pre-intervention level of intent and vaccine type. Side effect worry and perceived severity mediated the effect of Positive vs. Negative Framing across vaccines.

CONCLUSION

Positive framing of side effect information appears superior for increasing vaccine intent relative to the standard negative wording currently used.

PRE-REGISTRATION

See: aspredicted.org/LDX_2ZL.

Using Health Behavior Theory to Address COVID-19 Vaccine Hesitancy: A Scoping Review of Communication and Messaging Interventions

Vaccine hesitancy has been among the most vexing challenges during the COVID-19 pandemic, ultimately leading to maladaptive health behaviors such as vaccine delay and refusal. A variety of approaches have been employed to address this problem, including communication and messaging interventions targeting the underlying determinants of vaccine hesitancy. However, there exists no published evidence synthesis examining how such interventions are using health behavior theory to address COVID-19 vaccine hesitancy. The purpose of this study was to conduct a scoping review of health communication and messaging interventions aimed at addressing COVID-19 vaccine hesitancy, and to systematically evaluate the use of health behavior theory in the design of these interventions. The review followed a five-step iterative framework proposed by Levac and colleagues. Comprehensive searches using an exhaustive list of keyword combinations were used across three online databases to identify articles to screen for inclusion. A structured, validated coding scheme was then applied to assess the use of health behavior theory. Additional study data were extracted using a separate structured form. A total of 36 articles published between January 2020 and February 2022 met inclusion criteria and were included in the review. Ten studies (27.7%) did not mention or use health behavior theory at all. Most studies (n = 26) at least mentioned theory or theory-relevant constructs, with 26 different theories and 52 different theoretical constructs represented in the sample. Although theory and theoretical determinants of vaccination behavior were often mentioned, few studies used theory to specify and target causal pathways of behavior change, and only one study targeted misinformation as a determinant of vaccine hesitancy. The findings from this review provide critical insight into the state of theory-based intervention design and point to significant gaps in the literature to prioritize in future research.

COVID-19 vaccination coverage and associated factors in seasonal fruit workers in Lleida

Objectives

Seasonal fruit workers are a high-risk group for SARS-COV-2 infection. We aimed to estimate vaccination coverage and factors associated with vaccination in seasonal fruit workers.

Methods

We carried out an anonymous survey of seasonal fruit workers in the 2021 campaign in Baix Segria region and Lleida city (Spain) on vaccination, knowledge and attitudes about the COVID-19 vaccine. Univariate and bivariate descriptive analyses were performed comparing vaccinated versus non-vaccinated. Multivariate analysis was performed using to assess factors associated to vaccination uptake.

Results

We included 286 seasonal workers. The prevalence of confirmed COVID-19 background was 39.5% and overall vaccination coverage was 78.7%. Factors associated with vaccination were age (aOR = 0.96; 95% CI: 0.94-0.99), good knowledge of disease (aOR = 1.87; 95% CI : 1.01-3.47) and having a high-perceived vaccine effectiveness (aOR = 2.94; 95% CI : 1.50-5.73). High vaccination coverage in workers was associated to knowledge (OR = 3.69; 95% CI: 1.61-8.48), safe transport (OR = 2.84; 95% CI: 1.40-5.76) and appropriate housing (OR = 2.62; 95% CI: 1.25-5.46) as important non-pharmacological measures to reduced transmission.

Conclusion

The study confirms the high prevalence of COVID-19 history and moderate vaccination coverage in seasonal fruit workers. Health education programs to improve knowledge about COVID-19 and its vaccination can help improve vaccination uptake.

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.

A comparative analysis of experienced uncertainties in relation to risk communication during COVID19: a four-country study

Background

During outbreaks, uncertainties experienced by affected communities can influence their compliance to government guidance on public health. Communicators and authorities are, hence, encouraged to acknowledge and address such uncertainties. However, in the midst of public health crises, it can become difficult to define and identify uncertainties that are most relevant to address. We analyzed data on COVID-19-related uncertainties from four socio-economic contexts to explore how uncertainties can influence people’s perception of, and response to Risk Communication and Community Engagement (RCCE) strategies.

Results

This qualitative study, which adopts an interpretative approach, is based on data from a documentary review, key informant interviews (KII), and focus group discussions (FGD) with members of the general public and people with barriers to information from Germany, Guinea, Nigeria, and Singapore. Transcripts from the KII and FGD were coded and analyzed thematically. We interviewed a total of 155 KIs and conducted 73 FGD. Our analysis uncovered a divergence between uncertainties deemed relevant by stakeholders involved in policy making and uncertainties that people reportedly had to navigate in their everyday lives and which they considered relevant during the pandemic. We identified four types of uncertainties that seemed to have influenced people’s assessment of the disease risk and their trust in the pandemic control strategies including RCCE efforts: epidemiological uncertainties (related to the nature and severity of the virus), information uncertainties (related to access to reliable information), social uncertainties (related to social behavior in times of heightened risk), and economic uncertainties (related to financial insecurities).

Conclusion

We suggest that in future outbreaks, communicators and policy makers could improve the way in which affected communities assess their risk, and increase the trust of these communities in response efforts by addressing non-epidemiological uncertainties in RCCE strategies.

Positive Attribute Framing Increases COVID-19 Booster Vaccine Intention for Unfamiliar Vaccines

Positive framing has been proposed as an intervention to increase COVID-19 vaccination intentions. However, available research has examined fictitious or unfamiliar treatments. This pre-registered study (aspredicted#78369) compared the effect of standard negatively framed EU patient information leaflets (PILs), with new positively framed PILs, on booster intentions (measured pre- and post-intervention) for AstraZeneca, Pfizer, and Moderna COVID-19 vaccines. A representative sample of 1222 UK-based adults was randomised to one of six groups in a factorial design with framing (Positive vs. Negative) and vaccine familiarity (same (as previous), familiar, unfamiliar) as factors. The benefit of positive framing was hypothesised to be strongest for the least familiar vaccine (Moderna). Framing was moderated by familiarity, where only the unfamiliar vaccine showed a benefit of positive relative to negative Framing. Framing and familiarity also interacted with baseline Intention with the effect of framing on the unfamiliar vaccine especially pronounced at low baseline Intent. Conversely, standard negative framing appeared to increase intentions for familiar vaccines at low baseline intent. Findings provide important evidence that positive framing could improve vaccine uptake globally when switches or new developments require individuals to receive less familiar vaccines. Positive framing of familiar vaccines, however, should be treated with caution until better understood.

Effectiveness of message framing in changing COVID-19 vaccination intentions: Moderating role of travel desire

This research examines the effectiveness of message framing, message appeal and information content in changing respondents' COVID-19 vaccination intentions through influencing their vaccine risk perceptions. Furthermore, the moderating effect of travel desire on the relationship between vaccine risk perceptions and changing vaccination intentions is examined. In doing so, two rounds of data that were collected from the same respondents. The first survey recorded respondents' vaccination intentions, travel desire and socio demographics. A follow up survey tested cause-and-effect relationships on the proposed relationships using a 2 (message frame: gain, loss) x 2 (message appeal: rational, emotional) ×2 (information content: subjective, objective) between-subjects online experimental design. Findings suggest that loss-framed messages are more effective than gain-framed and emotional-rational messages in reducing risk perceptions and, thus, changing vaccination intentions. Travel desire is found to moderate the effect of vaccine risk perception on vaccination intentions by weakening the negative effect of vaccine risk perception on vaccination intention. Findings show the importance of travel desire along with message framing and message appeal on changing individuals' COVID-19 vaccination intentions in public health communications.

Characteristics and Comparison of Adverse Events of Coronavirus Disease 2019 Vaccines Reported to the United States Vaccine Adverse Event Reporting System Between 14 December 2020 and 8 October 2021

Background

This study assessed and compared the frequency and type of adverse events (AEs) of the Pfizer-BioNTech, Moderna, and Janssen coronavirus disease 2019 (COVID-19) vaccines reported in the Vaccine Adverse Event Reporting System (VAERS).

Methods

A retrospective analysis examined VAERS reports between 14 December 2020 and 8 October 2021 and focused on AE reports related to COVID-19 vaccines and AE outcomes [e.g., emergency room (ER) visits after being vaccinated, hospitalization, prolongation of existing hospitalization, life-threatening events, disability, birth defect, and death]. Reporting odds ratios (RORs) and Breslow-Day statistics were used to compare AE reporting between COVID-19 and non-COVID vaccines and between individual COVID-19 vaccines.

Results

A total of 604,157 AEs of COVID-19 vaccines were reported, including 43.51% for the Pfizer-BioNTech vaccine, 47.13% for the Moderna vaccine, and 9.12% for the Janssen COVID-19 vaccine. About 12.56% of patients visited ER after being vaccinated, 5.96% reported hospitalization, and 1.52% reported life-threatening events. Among the number of death cases (n = 7,674; mean age = 73), 2,025 patients (26.39%) had hypertension and 1,237 (16.12%) patients had cancer. RORs between COVID-19 vaccines and non-COVID vaccines identified increased ROR in ER visits, hospitalization, and life-threatening events. The results of the Breslow-Day statistics indicated heterogeneities between the disproportionality of reports across the four serious AE outcomes (i.e., ER visits, hospitalization, life-threatening events, and disability) between individual COVID-19 vaccines.

Conclusion

Most current VAERS reports showed that the most commonly reported AEs of COVID-19 vaccines were mild. Cases with a mortality outcome tended to occur in older adults with underneath conditions. Close ongoing surveillance in the safety of COVID-19 vaccines is critical and will inform the use of individual COVID-19 vaccines. Given the known limitations associated with the passive spontaneous reporting system, such as VAERS, our findings need to be further assessed and verified through longitudinal, large healthcare data systems.

The Effectiveness of Interventions for Increasing COVID-19 Vaccine Uptake: A Systematic Review

Vaccination is vital to protect the public against COVID-19. The aim of this systematic review is to identify and evaluate the effectiveness of interventions to increase COVID-19 vaccine uptake. We searched a range of databases (Embase, Medline, Psychology & Behavioral Science, PsycInfo, Web of Science and NIH Preprints Portfolio) from March 2020 to July 2021 for studies which reported primary quantitative or qualitative research on interventions to increase COVID-19 vaccine uptake. Outcome measures included vaccination uptake and reported intention to vaccinate. Reviews, position papers, conference abstracts, protocol papers and papers not in English were excluded. The NHLBI quality assessment was used to assess risk of bias. In total, 39 studies across 33 papers met the inclusion criteria. A total of 28 were assessed as good quality. They included interventions relating to communication content, communication delivery, communication presentation, policy or vaccination delivery, with 7 measuring vaccination uptake and 32 measuring vaccination intention. A narrative synthesis was conducted, which highlighted that there is reasonable evidence from studies investigating real behaviour suggesting that personalising communications and sending booking reminders via text message increases vaccine uptake. Findings on vaccination intention are mixed but suggest that communicating uncertainty about the vaccine does not decrease intention, whereas making vaccination mandatory could have a negative impact. Although much of the research used experimental designs, very few measured real behavioural outcomes. Understanding which interventions are most effective amongst vaccine-hesitant populations and in the context of booster vaccinations will be important as vaccine roll outs continue across the world.

Message framing and COVID-19 vaccination intention: Moderating roles of partisan media use and pre-attitudes about vaccination

One of the ways to overcome the sheer devastation of the COVID-19 pandemic is to get vaccinated. However, vaccine hesitancy could be a significant barrier. The main purposes of the current study are to examine the impact of four types of theory-driven messages on COVID-19 vaccination intention and to understand the moderating role of partisan media use and vaccination attitudes. The study used a between-subject randomized online experiment with four conditions. The manipulation messages were presented as screenshots from the CDC's Facebook page. The total number of participants were 387 (female 43%, mean age 37 years). The participants were from the U.S. and older than 18 years. The findings show that loss vs. gain message frames did not have any impact on COVID-19 vaccine intention. The moderating effects of conservative media and attitudes show that in general, those who consumed lower conservative media and held positive attitudes were higher on vaccine intention, and individual vs. collective frames did not have a strong impact. However, among those participants who scored high on conservative media use, and held negative vaccination attitudes, the individual frame had a higher impact on vaccine intention. The current study experimentally tested the intertwined relationships among message frames, partisan media use, and attitudes on vaccine intention. These relationships are critical considering the political nature of the pandemic.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12144-022-02851-3.

Compliance Indicators of COVID-19 Prevention and Vaccines Hesitancy in Kenya: A Random-Effects Endogenous Probit Model

Vaccine hesitancy remains a major public health concern in the effort towards addressing the COVID-19 pandemic. This study analyzed the effects of indicators of compliance with preventive practices on the willingness to take COVID-19 vaccines in Kenya. The data were from the COVID-19 Rapid Response Phone Surveys conducted between January and June 2021 during the fourth and fifth waves. The data were analyzed with the random-effects endogenous Probit regression model, with estimated parameters tested for robustness and stability. The results showed that willingness to take vaccines increased between the fourth and fifth waves. Compliance with many of the preventive practices also improved, although the utilizations of immune system-promoting practices were very low. The panel Probit regression results showed that compliance indicators were truly endogenous and there was existence of random effects. Immune system-boosting and contact-prevention indicators significantly increased and decreased the willingness to take vaccines, respectively (p < 0.01). The experience of mental health disorders in the form of nervousness and hopelessness also significantly influenced vaccine hesitancy (p < 0.10). Willingness to take vaccines also significantly increased among older people and those with a formal education (p < 0.01). Different forms of association exist between vaccine hesitancy and the prevention compliance indicators. There is a need to properly sensitize the people to the need to complement compliance with COVID-19 contact-prevention indicators with vaccination. Addressing mental health disorders in the form of loneliness, nervousness, depression, hopelessness and anxiety should also become the focus of public health, while efforts to reduce vaccine hesitancy should focus on individuals without formal education, males and youths.

Racial differences in institutional trust and COVID-19 vaccine hesitancy and refusal

BACKGROUND

Previous research has indicated that demographic differences affect COVID-19 vaccination rates. Trust, in both the vaccine itself and institutional trust, is one possible factor. The present study examines racial differences in institutional trust and vaccine status among a nationally representative sample of adults in the United States.

METHODS

Data for the current study was collected as part of Wave 8 Omnibus 2000 survey conducted by RAND ALP and consisted of 2080 participants. Responses were collected through the online RAND ALP survey in March 2021.

RESULTS

Trust in the scientific community was the strongest predictor for already receiving at least one dose of the COVID-19 vaccine at the time of study. Asians had a significantly higher trust in the scientific community compared to all other groups. Results also showed a significant difference in level of trust of the government's response to the COVID-19 pandemic with Indian/Alaskan Natives reporting lower trust compared to Whites, Blacks and Asians. Asians also had a significantly higher level of trust when compared to those who identified as racial Other. Those who identify as American Indian/Alaskan Natives had the lowest levels of institutional trust. Trust in the government's response was not indicative of vaccination within the sample.

CONCLUSIONS

Strategies to increase trust of the scientific community can be employed to address vaccine hesitancy through community-based initiatives and building of partnerships between the scientific community and local community stakeholders.

The impact of COVID-19

BACKGROUND

Behavioral responses to the COVID-19 pandemic have become highly polarized, and public health initiatives often try to use different frames to influence behavior. If the polarization of behaviors is related to differences in responses to frames, then different health messages could be targeted to different groups to influence behavior.

OBJECTIVE

To determine whether risk preferences and susceptibility to gain/loss frames have been affected by COVID-19 and whether they differ along partisan lines.

METHODS

Using repeated cross-sectional data from a nationally representative dataset in the United States replicating the disease outbreak scenario collected before and after the onset of COVID-19, we test whether responsiveness to the gain/loss frames has changed over time and whether the responsiveness varies by political affiliation.

RESULTS

The experimental results show that the risk preferences of the U.S. population is very susceptible to the framing of choices, consistent with the literature finding risk loving preferences under the loss frame and risk aversion under the gain frame. However, the experience of COVID-19 does not appear to have changed the responsiveness, nor are there significant differences between conservatives/Republicans and liberals/Democrats.

CONCLUSION

Targeting different partisan groups with different risk-related message frames is unlikely to be effective at altering behaviors.

Attitudes and Intentions toward COVID-19 Vaccination among Spanish Adults: A Descriptive Cross-Sectional Study

Vaccination against SARS-CoV-2 is postulated as the most effective measure to control the COVID-19 pandemic. However, the use of other protection measures is necessary to efficiently combat the spread of the virus. The aim of the present study was to determine the attitudes and intentions toward COVID-19 vaccination among non-regular social media users in Spain and to analyze how these factors could condition the acceptance of other personal protective measures once an individual has received the COVID-19 vaccine. A cross-sectional design was used in this work. In total, 719 subjects, ≥18 years old and of both sexes, were recruited from primary public healthcare centers to self-complete a questionnaire between March and April 2021. The majority of participants had a positive attitude toward vaccination and showed high levels of intention to be vaccinated. Likewise, except those participants who considered the vaccine to be the most effective measure to fight the COVID-19 pandemic, the rest of the participants highlighted the importance of continuing to limit social interactions and/or wearing masks even after being vaccinated. Since vaccination can create a perception of total immunity against SARS-CoV-2, it is necessary that healthcare staff organize effective awareness campaigns on the importance of maintaining personal protective measures until vaccination coverage is greater.

Attitudes, acceptance and hesitancy among the general population worldwide to receive the COVID-19 vaccines and their contributing factors: A systematic review

BACKGROUND

High rates of vaccination worldwide are required to establish a herd immunity and stop the current COVID-19 pandemic evolution. Vaccine hesitancy is a major barrier in achieving herd immunity across different populations. This study sought to conduct a systematic review of the current literature regarding attitudes and hesitancy to receiving COVID-19 vaccination worldwide.

METHODS

A systematic literature search of PubMed and Web of Science was performed on July 5th, 2021, using developed keywords. Inclusion criteria required the study to (1) be conducted in English; (2) investigate attitudes, hesitancy, and/or barriers to COVID-19 vaccine acceptability among a given population; (3) utilize validated measurement techniques; (4) have the full text paper available and be peer-reviewed prior to final publication.

FINDINGS

Following PRISMA guidelines, 209 studies were included. The Newcastle Ottawa (NOS) scale for cross-sectional studies was used to assess the quality of the studies.Overall, vaccine acceptance rates ranged considerably between countries and between different time points, with Arabian countries showing the highest hesitancy rates compared with other parts of the world.

INTERPRETATION

A variety of different factors contributed to increased hesitancy, including having negative perception of vaccine efficacy, safety, convenience, and price. Some of the consistent socio-demographic groups that were identified to be associated with increased hesitancy included: women, younger participants, and people who were less educated, had lower income, had no insurance, living in a rural area, and self-identified as a racial/ethnic minority.

Information Framing Effect on Public's Intention to Receive the COVID-19 Vaccination in China

The aims of the study were (1) to explore information framing effect on the public's intention to receive the COVID-19 vaccination and (2) to understand the key factors influencing the intention of COVID-19 vaccinations in China. An online questionnaire survey was conducted to explore the influence of demographic characteristics, individual awareness, social relationship, risk disclosure, perceived vaccine efficacy, and protection duration under the assumptions of information framing. The results showed that (1) the persuasion effect under loss frame was higher than that under gain frame (B = 0.616 vs. 0.552); (2) there was no significant difference between sex, age, income, occupation, educational background and residence for the participants' intention to be vaccinated; whether family members/friends were vaccinated had a strong correlation with their vaccination intention under the gain frame; (3) the higher the understanding of COVID-19 and the compliance with government COVID-19 prevention and control measures were, the higher the vaccination intention was; (4) risk disclosure had the greatest impact on people's COVID-19 vaccination intention; (5) perceived vaccine effectiveness and duration of protection had little effect on people's intention to receive vaccination. The influence of information framing on the intention of COVID-19 vaccination is different. The publicity of relevant health information should pay attention to the influence of information framing and contents on the behavior of public vaccination, so as to enhance public health awareness and promote the vaccination of the whole population.

Factors Influencing Public Attitudes towards COVID-19 Vaccination: A Scoping Review Informed by the Socio-Ecological Model

Major hindrances to getting a COVID-19 vaccine include vaccine hesitancy, skepticism, refusal, and anti-vaccine movements. Several studies have been conducted on attitudes of the public towards COVID-19 vaccines and the potential influencing factors. The purpose of this scoping review is to summarize the data available on the various factors influencing public attitudes towards COVID-19 vaccination. This scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Statement. PubMed, Embase, Web of Science, and Cochrane Central were searched without restrictions to reclaim all publications on the factors that shape individuals' attitudes towards COVID-19 vaccines from 1 January 2020 to 15 February 2021. Fifty studies were included. The scoping review revealed that the factors influencing public attitudes towards COVID-19 vaccines were embedded within the different levels of the socio-ecological model. These factors included the sociodemographic characteristics of the individuals, individual factors, social and organizational factors. In addition, certain characteristics of COVID-19 vaccines themselves influenced public attitudes towards accepting the vaccines. Understanding various population needs and the factors shaping public attitudes towards the vaccines would support planning for evidence-based multilevel interventions in order to enhance global vaccine uptake.