Vaccine Hesitancy Under the Magnifying Glass: A Systematic Review of the Uses and Misuses of an Increasingly Popular Construct

Quantitative Measurement of Individual and Contextual Determinants of COVID-19 Vaccination in General Population Samples: A Scoping Review

BACKGROUND

This scoping review aims to map the quantitative literature investigating vaccine-related individual and contextual determinants of COVID-19 vaccination uptake, identify and define constructs assessed, and describe the characteristics of self-report measures.

METHODS

A systematic search of electronic databases was conducted to capture peer-reviewed journal articles published between December 31, 2019, and December 25, 2021. Studies conducted in English and collecting data from general population samples using self-report measures of vaccine-related determinants of COVID-19 vaccination behavior were eligible. Data were analyzed using a descriptive statistics and content analysis, and constructs were mapped onto the COM-B model. The review pre-registration is available on the Open Science Framework ( https://osf.io/82fsz ).

RESULTS

This review identified 157 studies (6153 abstracts and 997 full texts screened) and 425 vaccine-related constructs were retrieved from included studies. Of these, 4% were mapped to capability factors, 85% to motivation, and 11% to opportunity. The most frequently assessed constructs were positive attitudes (19% of constructs), negative attitudes (16%), intention (10%), and beliefs (8%). Only 11% of studies used or adapted pre-existing measures in their surveys. Psychometric properties of self-report measures used were not reported in the majority of studies (60%).

CONCLUSIONS

Findings suggest a predominant focus on perceived individual-level predictors of COVID-19 vaccination with inconsistent measurement, potentially compromising research validity. This research highlights opportunities to explore social/environmental factors, establish unified definitions, and employ validated self-report measures for robust survey-based studies on COVID-19 vaccination determinants.

Vaccine Hesitancy and Its Epistemic Antecedents: A Meta-Analysis

Although much attention has been given to vaccine hesitancy, there is still considerable ambiguity regarding its epistemological antecedents. The current meta-analysis addresses this theoretical and practical gap by focusing on the interplay between trust, belief in conspiracy theories, and COVID-19 vaccine hesitancy (k = 32), as well as key moderators such as the availability of the vaccine and the state and progress of the pandemic. Overall, results indicate that while both trust and beliefs in conspiracy theories are important correlates of vaccine hesitancy, considerable difference emerges when adopting a more granular approach that distinguishes between types of trust (government, public health organizations, science, and healthcare professionals/providers) and conspiracies (specific versus general). These findings cement the importance of health communication, not only as a useful framework to study and understand vaccine hesitancy but also as a potential way to intervene in order to prepare for future infectious disease outbreaks.

COVID-19 Research in Communication Journals: A Structural Topic Modeling-Assisted Bibliometric Analysis

This article presents a bibliometric analysis of research on COVID-19 health communication. We reviewed and analyzed 1,851 articles published in 170 peer-reviewed communication journals between January 2020 and November 2022, to identify key bibliometric information and major research topics in this rapidly expanding field of research. The distribution of countries indicates that the United States is the most productive country, and researchers from Spain, China and the United Kingdom also play an important role. Health Communication is the most influential journal in terms of research productivity and impact. The analysis of highly cited references demonstrates the interdisciplinary nature of this research field. The topics generated by structural topic modeling show that scholars have responded to a variety of issues in COVID-19 communication, encompassing different levels of health communication, the effects of information dissemination, the impact on the general public as well as vulnerable populations, health preventive behaviors and communication technologies. This study aims to enhance researchers' understanding of the current state of this research field and provide insights for future studies.

Meaningful Media Experiences and Vaccination Message Communication: An Experimental Study with Vaccine-Hesitant Individuals

Guided by the eudaimonic media and the health persuasion literature, the current study explores how meaningful emotions elicited from entertainment media exposure decreases anti-vaccination attitudes among vaccine-hesitant individuals. Results of a between-subjects experiment (N = 409) showed that participants who viewed meaningful music videos (vs. neutral videos) and vaccination messages embedded in the user-generated comments reported more empathy, less reactance, and less anti-vaccination attitudes. Multigroup analysis revealed that this association was held for participants who were hesitant about whether they would get fully vaccinated, but not for participants who were determined to not get vaccinated. Theoretical and practical implications were discussed.

Quantitatively Identifying Messaging Topics to Encourage West Virginia nurses' COVID-19 Vaccination

Nurses are particularly influential to others as it relates to COVID-19 vaccination decision-making and are at higher risk of COVID-19 themselves. Yet, nurses' COVID-19 vaccination remains suboptimal. This study combines communication science frameworks with a novel conceptualize of identity-identity fusion-to explore why nurses may not vaccinate and what strategies might encourage them to protect themselves from COVID-19. Practicing nurses recruited from the West Virginia Nurses Association (N = 328) were asked about their nursing identity, COVID-19 threat perceptions, vaccination efficacy perceptions, vaccination social norms, and both vaccination and information seeking plans. Findings show that social norms may have particular influence over nurses' vaccination intentions, though this is unique to nurses who do not view themselves as completely "fused" with the nursing identity. "Fully fused" nurses, on the other hand, may respond well to information conveying their particular risk for COVID-19. Data suggest information on one's self-efficacy or ability to get vaccinated should be avoided, as it might discourage some nurses'vaccination. Findings are discussed in terms of how identity may influence vaccination.

Prospective Attitudes towards Respiratory Syncytial Virus (RSV) Vaccination: Validation of a Survey Instrument among Young Females in Jordan Pending Vaccine Authorization

In May 2023, the U.S. FDA advisors endorsed Pfizer's pregnancy-administered vaccine (branded ABRYSVO) to protect infants from respiratory syncytial virus (RSV) infection. Vaccination can reduce the burden of RSV-related respiratory disease, with previous studies showing its substantial medical and financial burden in Jordan. However, pregnant women may exhibit hesitancy to get vaccinated due to concerns about potential risks to themselves or their fetuses. This study aimed to assess the acceptance of the RSV vaccine among young females and identify the determinants influencing their decision using a newly constructed instrument. A survey instrument was developed and validated, comprising 26 items to measure RSV vaccine acceptance. A cross-sectional study design was employed, with data collection from a sample of females aged 18 to 45 residing in Jordan during 5-6 July 2023, using a convenient approach via an online distributed questionnaire. The final study sample comprised 315 respondents, with 67.6% who have heard of RSV before the study. If the vaccine was safe, effective, and provided freely, 70.2% showed willingness to get the RSV vaccine, 15.2% resisted, and 14.6% were hesitant. Principal component analysis identified six internally consistent sub-scales with the following suggested themes: Advice, Burden, Conspiracy, Dangers, Efficiency, and Fear, comprising 21 items collectively as assigned as the "ABCDEF" scale for RSV vaccine acceptance. RSV vaccine acceptance in this study was associated with the advice and fear constructs. The validated survey instrument successfully captured important determinants of RSV vaccine acceptance among young females. RSV vaccine promotion efforts should focus on the following: enhancing vaccine education, improving trust in healthcare institutions and providers, reducing burdens through resolving cost issues and focusing on the role of social support, addressing safety concerns, and tailoring communication strategies to effectively promote the benefits of the vaccine. These insights can inform public health policies and interventions aiming to promote RSV vaccination and mitigate the burden of RSV-related diseases among infants. Follow-up studies are recommended with pregnant women as the target group to assess their attitude towards RSV vaccination and to confirm the validity of the conceived ABCDEF survey instrument.

The Authorization of the First COVID-19 Vaccines Changed the Level and Nature of Intend to Get Vaccinated

Despite the abundance of literature on vaccine hesitancy, how public opinion changes during and after the authorization of a new vaccine remains an open question. The COVID-19 pandemic offers a unique case since the development and roll-out of the first generation of vaccines happened at unprecedented speed. To understand how the public's intent to get vaccinated changed around the emergency authorizations of the first COVID-19 vaccines, we ran a secondary analysis of survey data that consisted of rolling cross-sections of Facebook users in 23 countries (N = 375,627) between July 2020 and April 2021. In contrast to prior longitudinal work, we did not only investigate the change in levels of the intent to get vaccinated but also in the nature of it, i.e., the change in the influence of core predictors. Moreover, our data span a longer phase than prior work and included various countries in the Global South. We found that the intent to get vaccinated decreased around the time of the authorization of the first COVID-19 vaccines before it increased again. In the composition of people who refused vaccination or were undecided, notable differences were found for age, gender, and, most importantly, trust in health authorities as information sources before, around, and after the authorization of the vaccines. We conclude that the importance of trust-inducing communication in the early phase of a vaccination campaign cannot be overstated.

A model-based opinion dynamics approach to tackle vaccine hesitancy

Uncovering the mechanisms underlying the diffusion of vaccine hesitancy is crucial in fighting epidemic spreading. Toward this ambitious goal, we treat vaccine hesitancy as an opinion, whose diffusion in a social group can be shaped over time by the influence of personal beliefs, social pressure, and other exogenous actions, such as pro-vaccine campaigns. We propose a simple mathematical model that, calibrated on survey data, can predict the modification of the pre-existing individual willingness to be vaccinated and estimate the fraction of a population that is expected to adhere to an immunization program. This work paves the way for enabling tools from network control towards the simulation of different intervention plans and the design of more effective targeted pro-vaccine campaigns. Compared to traditional mass media alternatives, these model-based campaigns can exploit the structural properties of social networks to provide a potentially pivotal advantage in epidemic mitigation.

The Role of Existential Concerns in the Individual's Decisions regarding COVID-19 Vaccine Uptake: A Survey among Non-Vaccinated Italian Adults during the Third Wave of the Pandemic

Recent studies have suggested that health constructs embraced by the Terror Management Theory (TMT) and the Basic Psychological Needs Theory (BPNT) may drive individuals' COVID-19 health-related decisions. This study examines the relationships between existential concerns (ECs; within the TMT), basic psychological needs (BPNs; within the BPNT) and COVID-19 vaccine hesitancy (VH), as well as the mediating role of negative attitudes toward COVID-19 vaccines. A cross-sectional survey was carried out from April to May 2021 on a sample of two hundred and eighty-seven adults (Mage = 36.04 ± 12.07; 59.9% females). Participants provided information regarding existential concerns, basic psychological needs, attitudes toward COVID-19 vaccines and vaccine hesitancy for Pfizer-BioNTech and AstraZeneca vaccines separately. Higher vaccine hesitancy (32.1%) and vaccine resistance (32.8%) rates were found for AstraZeneca than for Pfizer-BioNTech COVID-19 vaccine (22.3% and 10.1%, respectively). Structural equation modeling showed that existential concerns were related to Pfizer-BioNTech and AstraZeneca vaccine hesitancy both directly and indirectly through negative attitudes toward potential side effects of COVID-19 vaccines. The findings of the study confirm that the TMT is efficient in explaining COVID-19 vaccine hesitancy. Targeted efforts are needed to increase the acceptance of COVID-19 vaccines.