The Role of Trust in COVID-19 Vaccine Acceptance: Considerations from a Systematic Review

The relationship between trust in federal oversight of vaccine safety and willingness to participate in COVID-19 clinical trials: a repeated measures study of Philadelphia residents (September 2021 - March 2023)

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) pandemic precipitated an urgent need for clinical trials to discover safe and efficacious treatments. We examined how COVID-19 experiences, clinical trial awareness, and trust in the vaccine safety process were associated with willingness to participate in COVID-19 clinical trials. The objective was to investigate the relationship between trust in federal oversight of vaccine safety and willingness to participate in clinical trials for COVID-19 treatment across four distinct time points over an 18-month period during the COVID-19 pandemic.

METHODS

We used four waves of data collected from September 2021 to March 2023 among 582 Philadelphia residents (with a missing data rate of 0.9%). Generalized estimating equations estimated the association between willingness to participate in COVID-19 clinical trials and participants' trust in the federal government's oversight of COVID-19 vaccine safety, COVID-19-related variables (COVID-19 related health challenges, history of COVID-19 infection), awareness of clinical trials and how to enroll in them, and sociodemographic characteristics (age, race/ethnicity, sexual orientation, gender, parental status, education, and insurance).

RESULTS

On average, willingness to participate in a COVID-19 clinical trial was positively associated with greater trust in the federal government's oversight of vaccine safety [β = 0.34, 95% confidence interval (CI): 0.15-0.53], having COVID-19 (β = 0.40, 95% CI: 0.08-0.73), awareness of clinical trials (β = 0.38, 95% CI: 0.04-0.73), and knowledge of how to enroll (β = 0.83, 95% CI: 0.44-1.23). Among sociodemographic characteristics, race/ethnicity (p = 0.001) and gender (p = 0.018) were identified as predictors for COVID-19 trial willingness.

CONCLUSION

Willingness to participate in clinical trials may be bolstered by strengthening the public's trust in the federal government's role within vaccine safety oversight, increasing the perceived relevance of clinical trials to individuals' health and well-being, and offering tailored information to educate diverse communities about ongoing trials and how to enroll in them.

Navigating vaccination choices: The intersecting dynamics of institutional trust, belonging and message perception among Congolese migrants in London, UK (a reflexive thematic analysis)

The COVID-19 pandemic disproportionately impacted intersectionally marginalised migrants, revealing systemic disparities in health outcomes and vaccine uptake. Understanding the underlying social and structural factors influencing health behaviours is necessary to develop tailored interventions for migrants, but these factors have been seldom explored. This qualitative study aimed to explore contextual factors shaping COVID-19 vaccination decision-making among Congolese migrants in the UK.A community-based participatory research study was designed and led by a community-academic partnership in London, UK (2021-2022). Peer-led, semi-structured interviews were conducted in Lingala with 32 adult Congolese migrants and explored beliefs, perceptions and lived experiences of migration, healthcare, vaccination and the COVID-19 pandemic. Reflexive thematic analysis generated two themes and a model conceptualising the vaccination decision-making process. Participants and community partners were financially compensated; ethics was granted by the University of London ethics committee (REC: 2021.0128).Participants highlighted the incompatibility of lockdown restrictions with their communal culture, which intensified feelings of exclusion and alienation. Concerns about COVID-19 vaccination were attributed to safety and effectiveness, partly informed by experiences and legacies of racial discrimination and exploitation. Inequality in the pandemic response and COVID-19 outcomes heightened participants' sense that their views and needs were being overlooked, and government sources and information were perceived as coercive. Our model depicts the interplay between institutional trust, belonging, and message perception, which shaped participants' vaccination decisions and led to (non-)engagement with COVID-19 vaccination. This research enhances understanding of how social and contextual factors may influence migrants' engagement with health interventions. It underscores the importance of partnering with migrant communities to understand their needs in context and co-design tailored interventions and inclusive messaging strategies that promote trust and belonging. Implementing systemic changes to address structural inequalities will be crucial to create an environment that supports engagement with health-protective behaviours and enhances health outcomes among migrant communities.

Socioeconomic determinants and reasons for non-acceptance to vaccination recommendations during the 3rd - 5th waves of the COVID-19 pandemic in Hungary

BACKGROUND

In Hungary, although six types of vaccines were widely available, the percentage of people receiving the primary series of COVID-19 vaccination remained below the EU average. This paper investigates the reasons for Hungary's lower vaccination coverage by exploring changing attitudes towards vaccination, socio-demographic determinants, and individual reasons for non-acceptance during the 3rd - 5th pandemic waves of COVID-19.

METHODS

The study's empirical analysis is based on representative surveys conducted in Hungary between February 19, 2021, and June 30, 2022. The study used a total of 17 surveys, each with a sample size of at least 1000 respondents. Binomial logistic regression models were used to investigate which socio-demographic characteristics are most likely to influence vaccine hesitancy in Hungary. The study analysed 2506 open-ended responses to identify reasons for vaccine non-acceptance. The responses were categorised into four main categories and 13 sub-categories.

RESULTS

Between the third and fifth wave of the pandemic, attitudes towards COVID-19 vaccination have significantly changed. Although the proportion of vaccinated individuals has increased steadily, the percentage of individuals who reported not accepting the vaccine has remained almost unchanged. Socio-demographic characteristics were an important determinant of the observed vaccine hesitancy, although they remained relatively stable over time. Individuals in younger age groups and those with lower socioeconomic status were more likely to decline vaccination, while those living in the capital city were the least likely. A significant reason behind vaccine refusal can undoubtedly be identified as lack of trust (specifically distrust in science), facing an information barrier and the perception of low personal risk.

CONCLUSION

Although compulsory childhood vaccination coverage is particularly high in Hungary, voluntary adult vaccines, such as the influenza and COVID-19 vaccines, are less well accepted. Vaccine acceptance is heavily affected by the social-demographic characteristics of people. Mistrust and hesitancy about COVID-19 vaccines, if not well managed, can easily affect people's opinion and acceptance of other vaccines as well. Identifying and understanding the complexity of how vaccine hesitancy evolved during the pandemic can help to understand and halt the decline in both COVID-19 and general vaccine confidence by developing targeted public health programs to address these issues.

The negative impact of misinformation and vaccine conspiracy on COVID-19 vaccine uptake and attitudes among the general public in Iraq

Background

Vaccine hesitancy is a major barrier to infectious disease control. Previous studies showed high rates of COVID-19 vaccine hesitancy in the Middle East. The current study aimed to investigate the attitudes towards COVID-19 vaccination and COVID-19 vaccine uptake among adult population in Iraq.

Methods

This self-administered survey-based study was conducted in August-September 2022. The survey instrument assessed participants' demographics, attitudes to COVID-19 vaccination, beliefs in COVID-19 misinformation, vaccine conspiracy beliefs, and sources of information regarding the vaccine.

Results

The study sample comprised a total of 2544 individuals, with the majority reporting the uptake of at least one dose of COVID-19 vaccination (n = 2226, 87.5 %). Positive attitudes towards COVID-19 vaccination were expressed by the majority of participants (n = 1966, 77.3 %), while neutral and negative attitudes were expressed by 345 (13.6 %) and 233 (9.2 %) participants, respectively. Factors associated with positive attitudes towards COVID-19 vaccination in multivariate analysis included disbelief in COVID-19 misinformation and disagreement with vaccine conspiracies. Higher COVID-19 vaccine uptake was significantly associated with previous history of COVID-19 infection, higher income, residence outside the Capital, disbelief in COVID-19 misinformation, disagreement with vaccine conspiracies, and reliance on reputable information sources.

Conclusion

COVID-19 vaccine coverage was high among the participants, with a majority having positive attitudes towards COVID-19 vaccination. Disbelief in COVID-19 misinformation and disagreement with vaccine conspiracies were correlated with positive vaccine attitudes and higher vaccine uptake. These insights can inform targeted interventions to enhance vaccination campaigns.

How effective is the BNT162b2 mRNA vaccine against SARS-CoV-2 transmission and infection? A national programme analysis in Monaco, July 2021 to September 2022

BACKGROUND

We quantified SARS-CoV-2 dynamics in different community settings and the direct and indirect effect of the BNT162b2 mRNA vaccine in Monaco for different variants of concern (VOC).

METHODS

Between July 2021 and September 2022, we prospectively investigated 20,443 contacts from 6320 index cases using data from the Monaco COVID-19 Public Health Programme. We calculated secondary attack rates (SARs) in households (n = 13,877), schools (n = 2508) and occupational (n = 6499) settings. We used binomial regression with a complementary log-log link function to measure adjusted hazard ratios (aHR) and vaccine effectiveness (aVE) for index cases to infect contacts and contacts to be infected in households.

RESULTS

In households, the SAR was 55% (95% CI 54-57) and 50% (48-51) among unvaccinated and vaccinated contacts, respectively. The SAR was 32% (28-36) and 12% (10-13) in workplaces, and 7% (6-9) and 6% (3-10) in schools, among unvaccinated and vaccinated contacts respectively. In household, the aHR was lower in contacts than in index cases (aHR 0.68 [0.55-0.83] and 0.93 [0.74-1.1] for delta; aHR 0.73 [0.66-0.81] and 0.89 [0.80-0.99] for omicron BA.1&2, respectively). Vaccination had no significant effect on either direct or indirect aVE for omicron BA.4&5. The direct aVE in contacts was 32% (17, 45) and 27% (19, 34), and for index cases the indirect aVE was 7% (- 17, 26) and 11% (1, 20) for delta and omicron BA.1&2, respectively. The greatest aVE was in contacts with a previous SARS-CoV-2 infection and a single vaccine dose during the omicron BA.1&2 period (45% [27, 59]), while the lowest were found in contacts with either three vaccine doses (aVE - 24% [- 63, 6]) or one single dose and a previous SARS-CoV-2 infection (aVE - 36% [- 198, 38]) during the omicron BA.4&5 period.

CONCLUSIONS

Protection conferred by the BNT162b2 mRNA vaccine against transmission and infection was low for delta and omicron BA.1&2, regardless of the number of vaccine doses and previous SARS-CoV-2 infection. There was no significant vaccine effect for omicron BA.4&5. Health authorities carrying out vaccination campaigns should bear in mind that the current generation of COVID-19 vaccines may not represent an effective tool in protecting individuals from either transmitting or acquiring SARS-CoV-2 infection.

Vaccine hesitancy and trust in sub-Saharan Africa

Lack of trust is a primary reason behind the global rise in vaccine hesitancy. Existing research on the trust-vaccine hesitancy nexus has almost exclusively focused on COVID-19 with the vast majority of studies examining industrialized countries. In this study, we investigated the influence of trust in different policy-relevant actors (government, science, media, pharmaceutical companies, society) on vaccine hesitancy for recently available vaccines related to polio and HPV which we benchmark against a COVID-19 vaccine. Leveraging unique primary data on 5203 individuals from six countries (Ghana, Kenya, Nigeria, South Africa, Tanzania, and Uganda), we showed that individuals' trust in the government and society are key predictors of vaccine hesitancy. Furthermore, we demonstrated that these relationships are remarkably stable across vaccine, disease, and country contexts.

Impact of prior SARS-CoV-2 infection on college students' hesitancy to receive additional COVID-19 vaccine booster doses: A study from Taizhou, China

Purpose

This study aimed to examine the impact of a history of SARS-CoV-2 infection on the hesitancy of college students to receive additional COVID-19 vaccine booster doses.

Methods

A population-based self-administered online survey was conducted in July 2024 in Taizhou, China. A total of 792 respondents were included in this study. Logistic regression was conducted to identify factors associated with college students' hesitation to receive booster doses of the COVID-19 vaccine.

Results

Of 792 respondents, 32.2 % hesitated to receive additional doses of the COVID-19 vaccine booster. Furthermore, 23.5 % of the respondents reported an increase in hesitancy to receiving additional COVID-19 vaccine booster doses compared to before they were infected with SARS-CoV-2. In the regression analyses, college students who had a secondary infection were more hesitant to receive additional COVID-19 vaccine booster doses (OR = 0.481, 95 % CI: (0.299-0.774), P = 0.003). Moreover, students with secondary infections who were male (OR = 0.417, 95 % CI: 0.221-0.784, P = 0.007), with lower than a bachelor's degree (OR = 0.471, 95 % CI: 0.272-0.815, P = 0.007), in non-medical majors (OR = 0.460, 95 % CI: 0.248-0.856, P = 0.014), and sophomores or below (OR = 0.483, 95 % CI: 0.286-0.817, P = 0.007) were more hesitant to receive additional COVID-19 vaccine booster doses.

Conclusion

A history of SARS-CoV-2 infection affects college students' hesitation to receive additional COVID-19 vaccine booster doses, which was higher in those who experienced secondary infections.

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.

COVID-19 Vaccine decision-making: trust among the transgender and disability communities in India

BACKGROUND

Historical marginalisation and ongoing trust deficits in health and government systems shape present-day vaccine perceptions among marginalised communities. This paper sought to understand the role of trust in decision-making about COVID-19 vaccine uptake in the transgender and disability communities in India.

METHODS

Using a participatory approach we interviewed 24 community representatives, identifying themselves as transgender individuals or as persons with disability, and 21 key informants such as vaccine programme managers, vaccine providers, and community advocates. We undertook an inductive thematic analysis of the data using a socio-ecological model.

RESULTS

Fear of side effects in relation to specific needs of the two communities and mistrust of systems involved in vaccination shaped four different pathways for vaccine decision-making. Mistrust of systems was influenced by past negative experiences with the health system, creating contexts in which information and misinformation are shared and interpreted. Participants negotiated their doubts about safety and mistrust of systems by interacting with different sources of influence showing patterns of decision-making that are dynamic, context-dependent, and intersectional.

CONCLUSION

These findings will help in determining the content, strategies and approaches to equitable vaccine communication for these two communities. The two communities ought to be included in vaccine trials. Vaccine information must respond to the specific needs of these two communities which could be enabled by collaboration and engagement with community members and influencers. Finally, long-term investment towards the needs of marginalised communities is vital to dismantle cycles of marginalisation and distrust and in turn improve vaccine acceptance and uptake.

Psychometric evaluation of the Trust in Science and Scientists Scale

Reliable and valid measurement of trust in science and scientists is important. Assessing levels of such trust is important in determining attitudes and predicting behaviours in response to medical and scientific interventions targeted at managing public crises. However, trust is a complex phenomenon that has to be understood in relation to both distrust and mistrust. The Trust in Science and Scientists Scale has been adopted with increasing frequency in large-scale public health research. Detailed psychometric evaluation of the scale is overdue and makes meaningful comparisons between studies that use the scale difficult. Here, we examine the scale's dimensionality across five separate samples. We find that two factors emerge that are divided by their item polarity. Implications for scale use and trust in science measurement are discussed.

Trust in federal COVID-19 vaccine oversight and parents' willingness to vaccinate their children against COVID-19: a cross-sectional study

BACKGROUND

Over half of the youth population in the United States, aged 6 months to 17 years, have not received the Coronavirus Disease 2019 (COVID-19) vaccine. Given parents' central role in vaccinating their children, we examined associations between parents' trust of the federal oversight of COVID-19 vaccine safety and their willingness to vaccinate their children against COVID-19.

METHODS

This cross-sectional study included 975 parents of minor children residing in Philadelphia who completed the online survey between September 2021 and February 2022. Trust was measured using a four-point Likert scale ranging from 'do not trust' to 'fully trust' for two variables: (1) trust in federal oversight of COVID-19 vaccine safety for children and (2) trust in federal oversight of COVID-19 vaccine safety for the general public. A multiple logistic regression evaluated associations between trust and parents' willingness to vaccinate their children, which was measured on a five-point Likert scale ranging from 'strongly disagree' to 'strongly agree.' The analysis was adjusted for race/ethnicity, age, sexual orientation, gender, education, insurance, and parents' vaccination status.

RESULTS

Analyses included 975 parents whose children had not previously been vaccinated against COVID-19 (mean age 36.79, standard deviation 6.4; 42.1% racial/ethnic minorities; 93.2% heterosexual; and 73.7% with a college degree). Greater trust regarding federal oversight of COVID-19 vaccine safety for children [adjusted odds ratio (aOR) = 1.52, 95% confidence interval (CI): 1.13-2.04] and for the public (aOR = 1.58, 95% CI: 1.17-2.14) were each associated with increased willingness to have their child vaccinated against COVID-19. Unvaccinated parents had decreased willingness compared to parents who had received at least one dose of the vaccine (aOR = 0.14, 95% CI: 0.04-0.41). College-graduate parents exhibited increased willingness compared to those without a college degree (aOR = 2.07, 95% CI: 1.52-2.81). Non-heterosexual parents showed increased willingness compared to heterosexual parents (aOR = 2.30, 95% CI: 1.20-4.76).

CONCLUSIONS

Trust in federal COVID-19 vaccine oversight was associated with parental willingness to vaccinate their children against COVID-19 among parents whose children have not yet been vaccinated. Identifying and addressing causes of mistrust are crucial next steps to promote child vaccination. Intervention efforts to address trust gaps should remain a public health priority.

Institutional trust is a distinct construct related to vaccine hesitancy and refusal

BACKGROUND

Vaccine hesitancy is driven by a heterogeneous and changing set of psychological, social and historical phenomena, requiring multidisciplinary approaches to its study and intervention. Past research has brought to light instances of both interpersonal and institutional trust playing an important role in vaccine uptake. However, no comprehensive study to date has specifically assessed the relative importance of these two categories of trust as they relate to vaccine behaviors and attitudes.

METHODS

In this paper, we examine the relationship between interpersonal and institutional trust and four measures related to COVID-19 vaccine hesitancy and one measure related to general vaccine hesitancy. We hypothesize that, across measures, individuals with vaccine hesitant attitudes and behaviors have lower trust-especially in institutions-than those who are not hesitant. We test this hypothesis in a sample of 1541 Canadians.

RESULTS

A deficit in both interpersonal and institutional trust was associated with higher levels of vaccine hesitant attitudes and behaviors. However, institutional trust was significantly lower than interpersonal trust in those with high hesitancy scores, suggesting that the two types of trust can be thought of as distinct constructs in the context of vaccine hesitancy.

CONCLUSIONS

Based on our findings, we suggest that diminished institutional trust plays a crucial role in vaccine hesitancy. We propose that this may contribute to a tendency to instead place trust in interpersonally propagated belief systems, which may be more strongly misaligned with mainstream evidence and thus support vaccine hesitancy attitudes. We offer strategies rooted in these observations for creating public health messages designed to enhance vaccine uptake.

Vaccine hesitancy and related factors among South African adults in 2021: unpacking uncertainty versus unwillingness

Background

Amidst widespread public health recommendations and availability of COVID-19 vaccinations, half of South African adults are vaccinated against COVID-19. This study investigated the socio-behavioral determinants of vaccine hesitancy in South Africa, where vaccine hesitancy was separated into unwilling ness and uncertainty to take a COVID-19 vaccine.

Methods

Data was collected from a large-scale public survey during June-October 2021 that included online and telephonic surveys. Vaccination hesitancy was based on the question "When available, would you take the COVID 19 vaccine?," with responses categorized into those who were willing, unwilling, and uncertain about taking a COVID-19 vaccine. Multinomial regression examined the association between socio-behavioral variables and vaccine hesitancy.

Results

Overall, 73.8% reported they would definitely or probably take the vaccine, 16.4% were uncertain and 9.9% reported they probably or definitely would not (n = 16,988). Younger age, White and Colored population groups, no influenza vaccination history, previous vaccination refusal, knowing someone who experienced a serious vaccination side-effect, misperceptions about vaccine benefits, cultural or religious discouragement from taking a COVID-19 vaccination, lack of governmental confidence, concerns about side-effects, perceived lack of safety information, and lack of trust in the pharmaceutical industry and in the information from health care providers were all associated with higher odds of being uncertain and unwilling to take a COVID-19 vaccination. Strengths of association for unwillingness and uncertainty varied by the explanatory variables. Concern about effectiveness due to fast development was associated with uncertainty to take the vaccine but not with unwillingness. Concerns about side-effects had stronger associations with uncertainty than with unwillingness, while previous vaccine refusal, misperceptions of the protective benefits of vaccines, White population group, religious/cultural discouragement, and lack of trust in the pharmaceutical industry and health care providers' information had stronger associations with unwillingness than uncertainty.

Conclusion

The determinants of COVID-19 vaccine hesitancy should be addressed in interventions to improve vaccine uptake. Public health interventions and health communication can be prioritized and tailored to the different forms of vaccination hesitancy.

COVID-19 vaccination likelihood among federally qualified health center patients: Lessons learned for future health crises

BACKGROUND

To prepare for rollout of a COVID-19 vaccine in fall 2020, there was an urgent need to understand barriers to ensuring equitable access and addressing vaccine skepticism and resistance. This study aimed to understand the association between trusted sources of COVID-19 information and likelihood of vaccination during that time, focusing on lessons learned to prepare for future public health crises.

METHODS

From December 2020-March 2021, we surveyed a probability-based, cross-sectional sample of 955 patients across seven federally qualified health centers (FQHCs) serving predominantly low-income, Black and White populations in southeastern Louisiana. Vaccination likelihood was measured on a 7-point scale; "very likely to vaccinate" was defined as score=7. Trust in healthcare provider was measured with a single survey item. High trust in personal contacts, government, and media, respectively, were defined as the highest tertiles of summative scores of trust items. Weighted multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for being very likely to vaccinate.

RESULTS

Participants were 56% Black, 64% women, mean age 44.6 years; 33% were very likely to vaccinate. High trust in healthcare provider (aOR=4.14, 95% CI 2.26-7.57) and government sources (aOR=3.23, 95% CI 1.98-5.28) were associated with being very likely to vaccinate.

CONCLUSIONS

During initial COVID-19 vaccination rollout, trust in healthcare providers and government sources of COVID-19 information was associated with likelihood to vaccinate in FQHC patients. To inform public health planning for future crises, we highlight lessons learned for translating community-relevant insights into direct action to reach those most impacted.

How Likes and Retweets Impacted Our Patients During the COVID-19 Pandemic

The growing dependence on social media for health-related information boomed during the COVID-19 pandemic, posing unprecedented challenges in navigating the vast amounts of information available right at our fingertips. Social media had a major impact on clinical decision-making affecting individuals, communities, and societies at large. In this review, we discuss the role of social media in amplifying information and misinformation as well as factors contributing to its reliance and prevalence. We review how medical providers have been impacted by this changing landscape, useful communication strategies to employ with in-office patient encounters, and how we can be active players in using social media as a tool for health promotion, correcting misinformation, and preparing for future pandemics.

From Conspiracy to Hesitancy: The Longitudinal Impact of COVID-19 Vaccine Conspiracy Theories on Perceived Vaccine Effectiveness

The embrace of coronavirus disease 2019 (COVID-19) vaccine conspiracies has been linked to vaccine hesitancy. This study aimed to investigate the relationship between COVID-19 vaccine conspiracy theories and perceived vaccine effectiveness. The study utilized a longitudinal follow-up study in which adults in Chile completed surveys in December 2020 (T1) and May 2021 (T2). The psychometric properties of the five-item instrument on conspiracy theories for the COVID-19 vaccine were evaluated using data from T1 (n = 578). A confirmatory one-factor structure with suitable indicators of reliability was found. The longitudinal analysis (n = 292) revealed that conspiracy theories about the COVID-19 vaccine in T1 were associated with lower beliefs in its effectiveness in T2. However, no significant association was found between beliefs in effectiveness in T1 and conspiracy theories in T2. The study suggests that beliefs in conspiracy theories may temporally precede beliefs in vaccine effectiveness for COVID-19. The results have implications for strategies to address vaccine conspiracy beliefs and their implementation at the public policy level.

Framing Effects on Willingness and Perceptions towards COVID-19 Vaccination among University Students in Italy: An Exploratory Study

Vaccine hesitancy is a diffused psychological phenomenon that has been increasingly addressed in several studies since the COVID-19 pandemic. Communication campaigns play a pivotal role influencing recipients' perceptions and may affect the likelihood to vaccinate or to show hesitancy. In the context of communicating risks during the COVID-19 pandemic, we hypothesized that highlighting different aspects of data on the effectiveness of vaccines would influence people's willingness and attitudes to vaccinate. In this exploratory study, we administered two versions of a survey to a convenience sample of students from three universities in Italy. In the first version, salience was placed on the effectiveness of the vaccine in terms of reducing the probability of infection. In the second version, salience was placed on the effectiveness of the vaccine in terms of reducing the probability of hospitalization after being infected by COVID-19. The results confirmed our hypothesis: participants reported that they were more willing to become vaccinated when exposed to the hospitalization frame (main dimension). Conversely, we found mixed effects of the frame on the following sub-dimensions: reliability, trust, protection, safety, and confidence. Taken together, we show that it is possible to influence, to some extent, university students' attitudes and perceptions toward COVID-19 vaccination by acting on how information is framed. We discuss the implications of these findings for the development of behaviorally informed policies.

Impact of the COVID-19 Pandemic on Attitudes toward Vaccination: Representative Study of Polish Society

The study explored the association between individuals' attitudes toward vaccination and their actual vaccination behavior. We also examined the impact of the coronavirus disease 2019 (COVID-19) pandemic and the ongoing vaccination debate on changing attitudes towards vaccination, specifically within different demographic groups. The survey was conducted among a representative sample of Poles (N = 805) using computer-assisted web interview (CAWI) technology. As demonstrated, those who identified themselves as strong vaccine supporters were statistically significantly more frequently to be vaccinated with COVID-19 booster doses, to follow a physician's recommendation on any vaccine without hesitation, and to be strengthened in their confidence in vaccines during the COVID-19 pandemic (p < 0.001 for all). However, over half of the responders declared themselves as moderate vaccine supporters/opponents, the groups whose further attitudes are likely to be affected by (mis)communication. Importantly, more than half of moderate vaccine supporters declared that their vaccine confidence was weakened during the COVID-19 pandemic, while 43% were not vaccinated against COVID-19. In addition, the study demonstrated that older and better-educated individuals were more likely to be COVID-19-vaccinated (p < 0.001 and p = 0.013, respectively). The results of this study imply that, in order to improve vaccine acceptance, it is essential to strengthen public health communication and avoid communication errors conducted during the COVID-19 pandemic.