Why Some People Are Hesitant to Receive COVID-19 Boosters: A Systematic Review

The role of interdependent self-construal in mitigating the effect of conspiratorial beliefs on vaccine acceptance

Infectious diseases pose significant challenges to public health, leading to illness and even death. Vaccinations are vital for protecting society, yet beliefs in conspiracy theories related to infectious diseases increase vaccine hesitancy. This paper delves into vaccination decisions in the context of COVID-19, which continues to strain the health care system. While past research focuses on countering conspiratorial beliefs with cognitive persuasion interventions, we propose a social intervention as an alternative. Our novel intervention seeks to mitigate the effects of conspiratorial beliefs by fostering individuals' interdependent self-construal - viewing oneself in the context of social relationships. Interdependent self-construal was operationalized in multiple ways (measured in Studies 1, 2 and 3; manipulated to test causality in Studies 4 and 5). Conspiratorial beliefs were also manipulated in Study 5. The results show that the association between conspiratorial beliefs and vaccine hesitancy is weakened among individuals whose interdependent self-construal is more accessible. Moreover, this effect was mediated by prosocial motivation. We discuss the implications of our findings for developing and communicating health policies and propose potential contexts where this intervention may be relevant, thereby providing valuable insights into enhancing societal well-being in the face of conspiratorial beliefs.

The evolution of vaccine hesitancy through the COVID-19 pandemic: A semi-structured interview study on booster and bivalent doses

We sought in-depth understanding on the evolution of factors influencing COVID-19 booster dose and bivalent vaccine hesitancy in a longitudinal semi-structured interview-based qualitative study. Serial interviews were conducted between July 25th and September 1st, 2022 (Phase I: univalent booster dose availability), and between November 21st, 2022 and January 11th, 2023 (Phase II: bivalent vaccine availability). Adults (≥18 years) in Canada who had received an initial primary series and had not received a COVID-19 booster dose were eligible for Phase I, and subsequently invited to participate in Phase II. Twenty-two of twenty-three (96%) participants completed interviews for both phases (45 interviews). Nearly half of participants identified as a woman (n = 11), the median age was 37 years (interquartile range: 32-48), and most participants were employed full-time (n = 12); no participant reported needing to vaccinate (with a primary series) for their workplace. No participant reported having received a COVID-19 booster dose at the time of their interview in Phase II. Three themes relating to the development of hesitancy toward continued vaccination against COVID-19 were identified: 1) effectiveness (frequency concerns; infection despite vaccination); 2) necessity (less threatening, low urgency, alternate protective measures); and 3) information (need for data, contradiction and confusion, lack of trust, decreased motivation). The data from interviews with individuals who had not received a COVID-19 booster dose or bivalent vaccine despite having received a primary series of COVID-19 vaccines highlights actionable targets to address vaccine hesitancy and improve public health literacy.

Impact of the COVID-19 vaccination on confusion around vaccination in general: A longitudinal study on a university population over 18 months

Even before the COVID-19 pandemic, vaccine hesitancy was one of the main global public health threats. Unfortunately, the COVID-19 crisis and its associated risks only reinforced this hesitancy. This study aimed to identify to what extent the COVID-19 vaccination affected confusion around vaccination in general, its change and any associated factors. A questionnaire was distributed to the university population of Liège between April-June 2021 (Time 1) and July-September 2022 (Time 2). The impact of the COVID-19 vaccination on confusion around vaccination in general (score 0 to 100) was divided into three groups based on the tertiles of the study sample at different times and whether or not any change had been observed. Ordinal and multinomial regression analyses were performed to assess the relationship between the confusion and various determinants. The sample consisted of 491 participants. Time 1 vs Time 2, 41.3% vs 35.4% seemed to be less confused, 24.2% vs 28.7% were moderately confused and 34.4% vs 35.8% more confused, respectively. In terms of change, 19.4% of participants were less confused, 55.2% had not changed their opinion and 25.5% were more confused. The determinants causing confusion at both times and regarding change were self-perception, health literacy, past vaccination experiences and COVID-19 related factors (COVID-19 vaccination intention and trust in source of information at Time 1; preferred source of information, trust in vaccine producers and conspiratorial beliefs at Time 2; trust in vaccine producers for change). The results demonstrated that the COVID-19 vaccination impacted confusion around vaccination in general. Both unrelated and related COVID-19 factors, particularly regarding the progression of the pandemic, seem to have contributed to this confusion. Contributing factors require a personalised approach, evidence-based information being communicated with messages adapted to the situation and its evolution designed to allay individuals' fears about vaccination.

Optimal Annual COVID-19 Vaccine Boosting Dates Following Previous Booster Vaccination or Breakthrough Infection

BACKGROUND

COVID-19 booster vaccinations mitigate transmission and reduce the morbidity and mortality associated with infection. However, the optimal date for booster administration remains uncertain. Geographic variation in infection rates throughout the year makes it challenging to intuit the best yearly booster administration date to effectively prevent infection, and also challenging to provide best guidance on how to alter booster administration in response to a breakthrough infection.

METHODS

We leveraged longitudinal antibody and reinfection probabilities with spatiotemporal projections of COVID-19 incidence to develop a geographically informed approach to optimizing the timing of booster vaccination. We assessed the delay in booster vaccination that is warranted following breakthrough infections whenever they occur during the year, enabling a personalized assessment of optimal timing that acknowledges and respects diversity of COVID-19 immune status, addressing a substantial barrier to uptake.

RESULTS

Yearly booster vaccination on any date is beneficial to prevention of infection. However, each location exhibits as much as a 3-4-fold range in degree of protection by date of uptake. Optimal COVID-19 booster vaccination dates are location-specific, typically in early autumn in the Northern Hemisphere. Infection late in the interval between boosts substantially alters the optimal boosting date.

CONCLUSIONS

Considerable benefit accrues from aptly timing COVID-19 booster vaccination campaigns, which can be tailored to specific locations. Individuals can acquire the greatest benefit from booster vaccination by timing it optimally, including delaying in cases of infection late in the interval between boosts. These results provide location-specific guidance for public health policy, healthcare provider recommendations, and individual decision-making.

Identifying influential factors using machine learning techniques on the intention to receive a COVID-19 booster dose and vaccine fatigue among partially vaccinated individuals

This study assesses COVID-19 booster intentions and hesitancy in Texas, a state known for its diversity and libertarian values. A survey was conducted with 274 participants residing in Texas between June and July 2022. The analysis examined sociodemographic and health-related factors, trusted information sources, and preventive behaviors. The survey focused on vaccinated participants and their intention to receive the booster dose, which was categorized into three outcomes: yes, no, and not sure. Machine learning techniques were employed to analyze the survey responses of vaccinated participants to identify the most critical factors. Among the participants, 113 expressed their intention to get the booster (41.2%), 107 did not plan to receive the booster (39.1%), and 54 remained undecided (19.7%). Our findings indicate that the perception of vaccine safety significantly influenced the decision to receive the booster dose. Those who reported trust in social media contacts as reliable information sources were more likely to intend to boost. Additionally, among those hospitalized when diagnosed with COVID-19, the largest proportion were unwilling to receive the booster (47.0%) compared to those who intended to receive the booster (33.3%). In contrast, most of those who believed they would be hospitalized if infected with COVID-19 intended to get the booster. Other factors did not demonstrate a significant association. Our findings are highly transferable and can offer valuable insights, particularly for countries where COVID-19 remains prevalent and are pivotal both presently and in the future for developing strategies to improve booster uptake and shape public health initiatives in epidemic and pandemic outbreaks.

Influencing Canadian young adults to receive additional COVID-19 vaccination shots: the efficacy of brief video interventions focusing on altruism and individualism

Younger adults, aged 18-39 years, exhibit low COVID-19 additional vaccine (i.e., vaccination beyond the original 2-dose series) uptake recommended in Canada. No study has examined how altruistic and individualistic messaging can influence COVID-19 additional dose intentions. The present study aimed to estimate the efficacy of altruism and individualism-based videos on vaccine intentions and to explore the multivariable associations between vaccine related individual psychosocial factors and intention to receive the COVID-19 vaccine. Using a web-based survey in a three-arm, pre-post randomized control trial design, we recruited Canadians aged 18-39 years in both English and French. Participants were randomly allocated in a 1:1:1 ratio to receive the active control (COVID-19 general information), control + altruism or control + altruism + individualism. The video interventions were developed with a media company, based on results of a focus group study conducted previously. The measurement of COVID-19 additional dosage intentions before and after completing the interventions was informed by the multistage Precaution Adoption Process Model. The McNemar Chi-square was used to evaluate within-group changes, and the Pearson Chi-square test was used to evaluate between-group changes post-intervention. The measurement of various psychosocial factors was informed by use of validated scale and self-report questions. We employed a generalized Structural Equation Model to evaluate the associations between COVID-19 vaccine intentions and the psychosocial factors. Analyses were performed on 3,431 participants (control: n = 1,149, control + altruism: n = 1,142, control + altruism + individualism: n = 1,140). Within-group results showed that participants transitioned significantly in all three groups in the direction of higher intentions for receiving additional COVID-19 vaccine doses. The between-group differences in post intervention vaccine intentions were not significant. We found that psychosocial factors that include, collectivism, intellectual humility, intolerance to uncertainty, religiosity, identifying as gender diverse, and being indigenous were associated with higher vaccine intentions, whereas pandemic fatigue was associated with lower vaccine intentions. Our study highlighted that a short video that includes altruism and individualism messaging or general COVID-19 information can increase intentions to vaccine among young adults. Furthermore, we gained a comprehensive understanding of various psychosocial factors that influence ongoing COVID-19 vaccination. Our findings can be used to influence public health messaging around COVID-19 vaccination.

Evidence brief on facilitators, barriers and hesitancy of COVID-19 booster doses in Canada

Background

Understanding the facilitators, barriers and hesitancy to accepting COVID-19 booster doses is important for encouraging recommended vaccination. This evidence brief summarizes literature on the intention to accept or reject COVID-19 vaccine booster doses and the factors associated with intention/uptake among individuals in Canada.

Methods

A database of COVID-19 literature established at the Public Health Agency of Canada was searched for articles referencing vaccination and knowledge, attitudes and behaviours towards COVID-19 boosters. A grey literature search of Canadian governmental and academic institutions was also conducted. Primary research conducted in Canada (n=21) and relevant systematic reviews of the global literature (n=8) were included in this evidence brief.

Results

Intentions to get a booster dose in the general population have decreased between 2021-2023, with intentions varying across subpopulations. In Canada and within the global systematic reviews, facilitators, barriers and hesitancy were similar. Older age was the most common factor positively associated with intention/uptake of a booster, and the most common motivators were government/healthcare provider recommendations and helping to protect others. The main reasons for hesitancy were concerns about vaccine side effects and a lack of belief in the vaccine's efficacy.

Conclusion

Intentions to get a booster dose have decreased in Canada. Understanding the reasons for vaccine hesitancy and motivators for obtaining a booster can help guide future public health COVID-19 booster vaccination programs.

Messaging to Reduce Booster Hesitancy among the Fully Vaccinated

Vaccine hesitancy was a serious problem in the United States throughout the COVID-19 pandemic, due in part to the reduction in public trust in science that accompanied the pandemic. Now we are facing a new, similar but more extensive problem: booster hesitancy. Even fewer Americans are current on the mRNA booster. We present the results of an experiment with residents of the US who received all initial doses of the mRNA vaccine but who were not up to date on the booster. Participants read a scientific explanation describing either the safety or the effectiveness of the boosters or nothing in the control group. The explanations significantly increased (compared to the control) participants' perceptions of the safety and effectiveness of the mRNA booster, as well as their willingness to get boosted. Explanations also improved emotions and attitudes toward the booster. Furthermore, although liberals were significantly more willing to get boosted than were conservatives, improvement due to the explanations was similar across political ideology groups. However, when interactions were observed, conservatives increased to a greater degree. Importantly, the explanations increased participants' perception of scientists' expertise and knowledge, as well as participants' trust in scientists and the vaccine technology.

Sociodemographic Inequalities in COVID-19 Booster Dose Vaccination Coverage: a Retrospective Study of 196 Provinces in Peru

BACKGROUND

The COVID-19 vaccination coverage shows variability in booster doses between residency areas or ethnicity. The aim of this study was to evaluate how sociodemographic conditions influence unequal vaccination coverage with booster doses against COVID-19 in Peru.

METHODS

A retrospective, ecological study with an evaluation of 196 provinces in Peru. The sociodemographic conditions were evaluated as sources of inequality (sex, age group, educational level, residence area, and ethnic group). The inequality measure used was the GINI, an index that show the inequal vaccination coverage with third and fourth booster doses against COVID-19 in Peruvians provinces. The index allow determinate a higher inequality when the value is near to 1, and a lower inequality when the value is near to 0. Also, the impact of each sociodemographic condition in the general inequality was evaluate with a decomposition analysis of GINI coefficient into Sk (composition effect), Gk (redistribution effect), Rk (differential effect).

RESULTS

In provinces evaluated the mean vaccine coverage for the third and fourth booster doses was 57.00% and 22.19%, respectively at twelve months since the beginning of vaccination campaign. The GINI coefficient was 0.33 and 0.31, for the third and fourth booster doses coverage, respectively. In the decomposition analysis, twelve months after the start of the third and fourth dose vaccination campaign, revealed higher Sk values for people living in rural areas (Sk = 0.94 vs. Sk = 2.39, respectively for third and fourth dose), while higher Gk values for Aymara (Gk = 0.92 vs. Gk = 0.92, respectively), Quechua (Gk = 0.53 vs. Gk = 0.53, respectively), and Afro-Peruvians (Gk = 0.61 vs. Gk = 0.61, respectively). Also, higher negative correlation in Rk values for people with elementary education (Rk=-0.43 vs. Rk=-0.33, respectively), aged between 15 and 19 years (Rk=-0.49 vs. Rk=-0.37, respectively), and Aymara (Rk=-0.51 vs. Rk=-0.66, respectively).

CONCLUSION

The rural residency area, lower education and Quechua, Aymara or Afro-Peruvians ethnicity determinated inequalities in vaccination coverage with booster doses against COVID-19 in Peruvian provinces.

COVID-19 point-of-care tests can identify low-antibody individuals: In-depth immunoanalysis of boosting benefits in a healthy cohort

The recommended COVID-19 booster vaccine uptake is low. At-home lateral flow assay (LFA) antigen tests are widely accepted for detecting infection during the pandemic. Here, we present the feasibility and potential benefits of using LFA-based antibody tests as a means for individuals to detect inadequate immunity and make informed decisions about COVID-19 booster immunization. In a health care provider cohort, we investigated the changes in the breadth and depth of humoral and T cell immune responses following mRNA vaccination and boosting in LFA-positive and LFA-negative antibody groups. We show that negative LFA antibody tests closely reflect the lack of functional humoral immunity observed in a battery of sophisticated immune assays, while positive results do not necessarily reflect adequate immunity. After booster vaccination, both groups gain depth and breadth of systemic antibodies against evolving SARS-CoV-2 and related viruses. Our findings show that LFA-based antibody tests can alert individuals about inadequate immunity against COVID-19, thereby increasing booster shots and promoting herd immunity.

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.

Influence of Environmental Risk Exposure on the Determinants of COVID-19 Booster Vaccination in an Urban Thai Population

This study aimed to identify the influence of environmental risk exposure levels on the predictive factors of COVID-19 booster dose vaccination in an urban Thai population in the post-pandemic era. Six study locations, including the three provinces with the highest environmental risk levels and the three provinces with the lowest environmental risk levels, were selected by calculating the environmental risk exposure indexes. Participants from the capital district of each province were chosen via the simple random sampling technique and interviewed using a structured questionnaire. A total of 1315 individuals were included in a sample in this study, and the best predictors of booster dose vaccination were determined using multiple regression analysis. The results showed that a high level of environmental risk exposure occurred in the provinces with a high number of total days exceeding the limits set for PM10 and high rates of mortality for lung cancer. The number of COVID-19 booster vaccinations given amount to 43.4% of the population during the post-COVID-19 pandemic period. Our multivariate analysis indicated that individuals in the working age group (≥25 years old); those with higher education (diploma degree and above); full-time employment (government and private sectors); those with high monthly incomes (≥USD144.1); and those in areas with the lowest risk level of environmental exposure significantly contributed to the number of booster dose vaccinations given during the post-pandemic period. To summarize, the rate of COVID-19 booster dose vaccination acceptance in Thailand was influenced by socio-economic factors with environmental concerns. These findings improve our understating of both the global pandemic and how environmental exposure affects behavioral change patterns and could improve the effectiveness of post-pandemic management.

Global disparities in COVID-19 vaccine booster dose (VBD) acceptance and hesitancy: An updated narrative review

The global deployment of COVID-19 vaccine booster dose (VBD) has been recognized as a promising therapeutic alliance to provide repeated immunity against the arrival of new variants. Despite scientific evidence supports the effectiveness of periodic doses, COVID-19 vaccine booster reluctance continues to thrive. This narrative review aimed to examine global COVID-19 vaccine booster dose (VBD) acceptance and summarize an up-to-date assessment of potential antecedents associated with VBD acceptance. A comprehensive search was performed in several reputable databases such as Medline (via PubMed), Scopus, Google scholar, and Web of Science from June 10th, 2023, to August 1st, 2023. All relevant descriptive and observational studies on COVID-19 VBD acceptance and hesitancy were included in this review. A total of fifty-eight (58) studies were included, with Asia representing the highest count with thirty-one (53%) studies, Europe with eleven (19 %), the United States with nine (16 %), and other regions (Africa and multi-ethnic) with seven (12 %). Worldwide, the pooled COVID-19 VBD acceptance rate was 77.09 % (95 % CI: 76.28-78.18), VBD willingness (n) = 164189, and the total sample (N) = 212,990. The highest and the lowest VBD acceptance rate was reported in Europe and American regions, respectively, 85.38 % (95 % CI: 85.02-85.73, (n) = 32,047, (N = 37,533) vs. 66.92 % (95 % CI: 66.56-67.4), (n) = 29335, (N) = 43,832. However, Asia and multi-ethnic areas reported moderately high VBD acceptance rate 79.13 % (95 % CI: 78.77-79.23, (n) = 93,994, (N) = 11,8779) and 72.16 % (95 % CI: 71.13-72.93, (n) = 9276, (N) = 12,853), respectively. The most common and key antecedents of COVID-19 VBD acceptance and hesitancy across the countries were "equal safety", "efficacy", "effectiveness", "post-vaccination side effects", "community protection" "family protection", "risk-benefit ratio", "booster necessity", "trust", and "variants control". Disparities in the uptake of COVID-19 VBD were observed globally, with the highest rates found in Europe, and the lowest rates in American regions. Multiple potential antecedents including safety, efficacy, and post-vaccination side effects were associated with VBD acceptance and hesitancy.

Demographic Characteristics Associated With Intentions to Receive the 2023-2024 COVID-19 Vaccine

INTRODUCTION

The U.S. Food and Drug Administration approved the updated 2023-2024 COVID-19 vaccines by Pfizer-BioNTech and Moderna on September 11, 2023. Despite the Centers for Disease Control and Prevention's recommendation that everyone aged ≥6 years receive the updated COVID-19 vaccine, the general public's intentions to receive the new 2023-2024 vaccine are unknown.

METHODS

Intentions to receive the new COVID-19 vaccine and the demographic predictors of those intentions were assessed from a survey of adult residents, aged ≥18 years, of Los Angeles County, California conducted in October 2023.

RESULTS

Of the 1,090 participants, 701 (64.3%) indicated they were planning on receiving the new COVID-19 vaccine, 217 (19.9%) responded no, and 172 (15.8%) were unsure. Male gender (versus female); age groups of 50-64 and ≥65 years (versus 18-29 years); and ≥$100,000 household income (versus ≤$49,999) were associated with higher odds of reporting yes than reporting no regarding their vaccination intentions. Asian and Hispanic race/ethnicity (versus Non-Hispanic White) were associated with higher odds of indicating not sure than the odds of indicating no vaccination intentions. A significantly higher proportion of not-sure respondents reported "I plan to wait and see if it is safe and may get it later", whereas a significantly higher proportion of no respondents reported "I don't believe I need a COVID-19 vaccine booster" and "I don't trust COVID-19 vaccines."

CONCLUSIONS

This study demonstrates demographic differences in attitudes toward COVID-19 vaccination intentions and highlights the importance of promotional messages and initiatives that target more hesitant populations. These messages should address possible side effects and vaccine safety.

COVID-19 Vaccine Hesitancy among Parents of Children Younger than 12 Years: Experience from a Tertiary Outpatient Clinic

This study explored parents' attitudes towards vaccinating their children against COVID-19 and the rate of vaccine hesitancy in Oman. A cross-sectional, online, self-administered questionnaire, previously validated and administered between June 2021 and May 2022, was used. The questionnaire consisted of nine items. Parents of children younger than 12 years were eligible for participation. A total of 384 participants, including 207 males (54%), completed the questionnaire, resulting in an 86% response rate (384/447). The results showed that 69% of participants were hesitant to vaccinate their children aged 1-11 years. In parents of children aged 1-4 years, vaccination status was significantly associated with vaccine hesitancy (odds ratio [OR], 0.116; 95% confidence interval [CI], 0.044-0.306; p = 0.001). Furthermore, after multivariable analysis, compared to the fathers, mothers were significantly less likely to be associated with vaccine hesitancy (OR, 0.451; 95% CI, 0.240-0.848; p = 0.013).

Trends in Intention to Take the Second Booster COVID-19 Vaccination and Associated Factors in China: Serial Cross-Sectional Surveys

BACKGROUND

The escalating complexity of the COVID-19 epidemic underscores the need for heightened attention to booster vaccinations. This study aims to examine the changing trend in the public's intention to receive the second COVID-19 booster vaccination over time and the associated factors following the COVID-19 policy optimization in China.

METHOD

Eight cross-sectional surveys utilizing SMS questionnaire links were conducted in Guangzhou, China, from December 2022 to April 2023. The Mann-Kendall test was employed to analyze the trend in intentions to receive the second booster vaccination across the survey time. Adjusted and multivariate logistic analyses were used to analyze the factors associated with vaccination intention. Parallel analyses were performed for two subgroups with different COVID-19 infection statuses.

RESULTS

A total of 9860 respondents were surveyed in the eight rounds, of which 8048 completed the first booster vaccination and were included in the analysis. The overall COVID-19 infection rate was 60.0% (4832/8048), while the overall vaccination intention was 72.2% (5810/8048) among respondents. The vaccination intention exhibited a significant declining trend over time, decreasing from 81.5% in December 2022 to 52.2% in April 2023. An adjusted logistic regression analysis revealed that anxiety and depression were negatively associated with an intention to receive the second booster vaccination, while COVID-19-related preventive behaviors and a high engagement in COVID-19-related information were positively associated with an intention to receive the second booster vaccination. A subgroup analysis revealed that the association between psychological and behavioral characteristics and vaccination intention remained relatively stable among individuals with different histories of COVID-19 infections.

CONCLUSION

There was a significant decline in the intention to receive the second booster vaccination following the optimization of the COVID policy in China. Our findings emphasize the urgency of the second booster vaccination and provide a foundation for the development of tailored interventions to enhance and sustain vaccination intention among the public.

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.

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.

The Prevalence and Determinants of Hesitancy for Regular COVID-19 Vaccination among Primary Healthcare Patients with Asthma or COPD in Greece: A Cross-Sectional Study

The emergence of novel coronavirus mutations and signs of the waning immunity provided by COVID-19 vaccines underscore the importance of regular vaccination. This study aimed to investigate the prevalence of regular COVID-19 vaccination hesitancy and the factors that influence it among patients with asthma or chronic obstructive pulmonary disease (COPD) who visited primary care centers. The cross-sectional study was conducted in six primary healthcare centers in Crete, Greece (October-December 2023). Participants completed a questionnaire, which included questions about socio-demographic characteristics, health status, previous COVID-19 booster vaccination, attitudes, and beliefs about COVID-19 vaccination. Multivariate logistic regression was used to identify the factors that influenced vaccine hesitancy. Of the 264 participants, 65% exhibited hesitancy towards COVID-19 booster vaccination. Female gender, middle age, lower educational attainment, depression diagnosis, concerns about vaccine side effects, lack of confidence in vaccine efficacy, and reliance on media information were positively associated to vaccine hesitancy. Conversely, those having a cardiovascular disease or type 2 diabetes, those generally adhering to the recommendations of the treating physician, and those having previously received the flu vaccine or more than three COVID-19 vaccine doses were positively associated with regular COVID-19 vaccinations. Consequently, our findings could help develop strategies that could potentially reduce regular vaccination hesitancy among patients with asthma or COPD.

Acceptability of COVID-19 booster vaccine in malaysia: a cross-sectional study

Despite the high efficacy and safety demonstrated in clinical trials, COVID-19 booster vaccination rates in Malaysia remain below 50% among the general public. This study explores the factors influencing public acceptance of the COVID-19 booster vaccine among the Malaysian population. The questionnaire included variables on sociodemographics, knowledge, and the Health Belief Model (HBM) constructs. Based on the Chi-squared test of contingencies, a t-test and multivariate logistic regression analysis on 411 collected responses, the findings revealed that older participants, individuals of Chinese ethnicity, and those with higher education levels and incomes were more willing to accept booster vaccinations. The analysis further identified perceived susceptibility, perceived severity and perceived barriers as significant predictors influencing booster vaccination acceptance rates. Healthcare policymakers may consider targeting interventions to diminish the obstacles associated with booster vaccinations. These intervention strategies include implementing health intervention programmes, such as public health awareness initiatives, to raise awareness of the risks and severity of COVID-19, ultimately encouraging higher uptake of booster vaccines.

Using behavioral theory to understand partisan differences in COVID-19 vaccination and booster intentions

In 2020, the Food and Drug Administration granted emergency use authorization for two COVID-19 vaccines. Two years later, the Centers for Disease Control and Prevention estimated that more than 250 million individuals had received at least one dose of the vaccine. Despite the large numbers of individuals vaccinated against COVID-19, partisan differences surrounding the COVID-19 vaccine emerged, creating a potential challenge for health communications aimed at increasing vaccine uptake. A better understanding of partisan differences in attitudes and intentions towards vaccination may help guide public health strategies aimed at increasing vaccine uptake. To determine whether a commonly used theory of behavioral intentions used to craft public health messages explains partisan differences in intentions. Data were drawn from a national panel of US adults and collected between February 21, 2022, and March 3, 2022, using an online survey (n = 1845). Among respondents identifying as either Democrat or Republican (n = 1466), path analysis models were estimated to test whether partisan differences in vaccination or booster intentions were explained by the theoretical constructs of protection motivation theory (PMT). PMT accounted for approximately half of the covariate-adjusted mean difference in COVID-19 vaccination intentions between Democrats and Republicans, and nearly all the mean difference in booster intentions. Party affiliation indirectly affected intentions via its association with perceived susceptibility to COVID-19, vaccine/booster efficacy, and perceived costs of getting a COVID-19 vaccine or booster dose. Compared with Democrats, Republicans may be less likely to get vaccinated or receive a booster dose because of beliefs that they are less susceptible to COVID-19, that the vaccine is less effective, and that vaccination comes with disadvantages. Theories of behavioral intentions can help to identify the underlying theoretical determinants driving behavioral differences between political groups.

What influences consumers' online medication purchase intentions and behavior? A scoping review

Objective: Consumers increasingly buy pharmaceuticals online. No scoping review has been carried out to summarize and synthesize the studies that have identified drivers of consumers' purchase intention and behavior from online pharmacies. Thus, we conducted a scoping review to explore the extent to which prior research has studied consumer purchase intentions and behavior related to online pharmacies, the drivers previously identified to explain consumers' online pharmacy purchase intentions and behavior, and how these antecedents differ between OTC and prescription medications. Then, we identified gaps in the published literature to form a comprehensive theory-based agenda for future research. Methods: We searched PubMed, Web of Science, and Scopus to retrieve relevant studies published in English in peer-reviewed journals. The search strategy identified forty-eight eligible studies. Results: We identified twelve types of factors influencing purchase intentions and behaviors from online pharmacies: demographics, convenience, availability, price, evaluations of the purchase environment, information sources, internet usage, prior experience, perceived risk, health insurance, privacy, and product. Our analysis also revealed differences between OTC and prescription medications in drivers of purchase intentions and behaviors. Conclusion: While demographic factors tended to be the most often measured influences on intentions and behavior, their role was generally inconsistent, with many contradictory results. However, other factors (e.g., convenience, availability, lower prices, and favorable evaluations toward the purchase environment) more consistently enhanced online medication purchase intentions and behavior. An extensive agenda for future research is advanced.

Community Level Correlates of COVID-19 Booster Vaccine Hesitancy in the United States: A Cross-Sectional Analysis

Introduction: Evidence exists that individual-level sociodemographic factors contribute to vaccine hesitancy, but it is unknown how community-level factors affect COVID-19 booster dose hesitancy. The current study aims to fill this knowledge gap by comparing data from a nationwide survey on COVID-19 vaccine hesitancy with a community-level indicator, i.e., the Distressed Communities Index (DCI). Methods: Attitudes toward vaccinations, vaccine literacy, COVID-19 vaccine confidence index, and trust were measured using a 48-item, psychometrically valid and reliable survey tool. In this study, 2138 survey participants residing in the United States were divided into quintiles of varying community distress levels based on their zip codes using the DCI. Data were analyzed through Chi-square, one-way ANOVA, and post hoc analysis with Tukey's test. Results: A significantly higher proportion of participants from the distressed communities had lower trust than their prosperous counterparts (26.6% vs. 37.6%, p < 0.001). On the contrary, participants from the prosperous communities had significantly higher vaccine confidence index scores than those in distressed communities (2.22 ± 1.13 vs. 1.70 ± 1.01, p < 0.001). Conclusions: These findings affirm the importance of developing community-level interventions to promote trust in COVID-19 vaccinations and increase booster dose uptake. From these results, future studies can examine the efficacy of various community-level interventions.

COVID-19 vaccination acceptance, safety and side-effects in European patients with severe asthma

Background

Vaccination is vital for achieving population immunity to severe acute respiratory syndrome coronavirus 2, but vaccination hesitancy presents a threat to achieving widespread immunity. Vaccine acceptance in chronic potentially immunosuppressed patients is largely unclear, especially in patients with asthma. The aim of this study was to investigate the vaccination experience in people with severe asthma.

Methods

Questionnaires about vaccination beliefs (including the Vaccination Attitudes Examination (VAX) scale, a measure of vaccination hesitancy-related beliefs), vaccination side-effects, asthma control and overall safety perceptions following coronavirus disease 2019 (COVID-19) vaccination were sent to patients with severe asthma in 12 European countries between May and June 2021.

Results

660 participants returned completed questionnaires (87.4% response rate). Of these, 88% stated that they had been, or intended to be, vaccinated, 9.5% were undecided/hesitant and 3% had refused vaccination. Patients who hesitated or refused vaccination had more negative beliefs towards vaccination. Most patients reported mild (48.2%) or no side-effects (43.8%). Patients reporting severe side-effects (5.7%) had more negative beliefs. Most patients (88.8%) reported no change in asthma symptoms after vaccination, while 2.4% reported an improvement, 5.3% a slight deterioration and 1.2% a considerable deterioration. Almost all vaccinated (98%) patients would recommend vaccination to other severe asthma patients.

Conclusions

Uptake of vaccination in patients with severe asthma in Europe was high, with a small minority refusing vaccination. Beliefs predicted vaccination behaviour and side-effects. Vaccination had little impact on asthma control. Our findings in people with severe asthma support the broad message that COVID-19 vaccination is safe and well tolerated.

Acceptance of COVID-19 vaccine booster dose among the people of Bangladesh: A cross-sectional study

Vaccine booster dose (VBD) provides a potential therapeutic alliance in preventing breakthrough infection and new variant's arrival while preserving long-lasting host immunity. This study aimed to analyze COVID-19 VBD willingness and identified the key determinants of VBD acceptance among the general people of Bangladesh. This survey-based study applied a quantitative research paradigm. A validated, anonymous, and multi-item questionnaire was adopted through a theoretical review of pertinent literature on the topic. Data were collected between August 2022─October 2022, and sampling was done randomly. A total of 704 individuals were invited via face-to-face interview approach; however, 13.8 % of them declined to give consent, which resulted in the participation of 607 potential respondents. The main outcome measure was COVID-19 VBD acceptance willingness. Binary logistic regression analysis was conducted to rationalize the study's objectives. The pooled COVID-19 booster vaccine acceptance rate was 70.0 % (95 % confidence Interval [CI]: 67─73) among Bangladeshi people. An analysis of binary logistic regression revealed that, out of 14 potential factors, "efficacy", "repeated immunity", "communication", and "trust" showed highly significant positive association (adjusted odds ratio [aOR ] = 2.151 95 % CI: 1.391─ 3.508, aOR = 2.033 95 % CI: 1.299─ 3.181, and aOR = 2.552 95 % CI: 1.557─4.183 respectively, p<0.01), and "equal safety", "risk-benefit ratio" and "community protection" had significant positive association (aOR = 1.739 95 % CI: 1.070─2.825, aOR = 1.712 95 % CI: 1.116─2.627, and aOR = 1.628 95 % CI: 1.395─0.998, p<0.05) with VBD acceptance. However, post-vaccination "side effects" showed significant negative (aOR = 0.393 95 % CI: 0.237─0.674, p<0.01) associations with VBD acceptance. The odds of accepting the COVID-19 vaccine booster was found 1.26, and it was found insignificant (p>0.05) in the Chi-squared test. Bangladeshi people expressed a moderately high level response to COVID-19 VBD acceptance. A positive attitude towards the COVID-19 VBD is an outcome of this study, regardless of the circumstances, as far as safety, efficacy, perceived health benefits, communication, trust, and community resistance are concerned. Post-vaccination side effects fear was the primary reason for booster dose skepticism as well as a barrier to administering booster shots. The confidence in COVID-19 VBD will be boosted when mass people are effectively communicated and vaccine's data become more available publicly.

The determinants of COVID-19 vaccination intention: a meta-review

Background

A large number of systematic reviews have been published that synthesized various determinants of COVID-19 vaccination intention (CVI). However, they reported inconsistent evidence. Therefore, we conducted a meta-review (systematic review of systematic reviews) to provide a comprehensive synthesis of factors influencing CVI.

Methods

This meta-review was conducted in accordance with PRISMA guidelines. PubMed, Scopus, Web of Science, and CINAHL were searched for systematic reviews published from 2020 to 2022 that examined the determinants of CVI. AMSTAR-2 critical appraisal tool was used to ensure the quality of included reviews, and ROBIS tool was used to evaluate the risk of bias.

Results

Globally, the average rate of COVID-19 vaccination intention was 56.97%. We identified 21 main determinants of CVI: socio-demographic, geographical location, social, political, government role, study timeline, attitude, perceived severity, perceived susceptibility, perceived benefits, perceived barriers, self-efficacy and perceived behavioral control, norms, trust, conspiracy theory/propaganda/misinformation, knowledge, information and communication, vaccination recommendation, vaccination history, history of COVID-19 infection, and health status and well-being.

Conclusions

These results suggest that COVID-19 vaccination intention is a complex process and is affected by numerous multidimensional factors. Therefore, integrated communication strategies and multifaceted interventions may be effective for improving vaccination intention against COVID-19.

COVID-19 Prevention Behaviours and Vaccine Acceptability, and Their Association with a Behaviour Change Campaign in Somalia: Analysis of a Longitudinal Cohort

Somalia experienced its first wave of COVID-19 infections in March 2020 and has experienced fluctuating infection levels since. Longitudinal data on suspected cases of COVID-19, attitudes, and behaviours were collected by telephone interviews of cash-transfer programme beneficiaries from June 2020-April 2021. A multi-media Social and Behaviour Change Communication (SBCC) campaign was designed and implemented from February 2021 to May 2021. Between the end of the first wave and the onset of the second the perceived threat from COVID-19 increased, with the proportion of respondents viewing it as a major threat increasing from 46% to 70% (p = 0.021). Use of face coverings increased by 24% (p < 0.001) and hand shaking and hugging for social greeting decreased, with 17% and 23% more people abstaining from these practices (p = 0.001). A combined preventative behaviour score (PB-Score) increased by 1.3 points (p < 0.0001) with a higher score in female respondents (p < 0.0001). During wave 2, vaccine acceptance was reported by 69.9% (95% CI 64.9, 74.5), overall. Acceptance decreased with increasing age (p = 0.009) and was higher in males (75.5%) than females (67.0%) (p = 0.015). Awareness of the SBCC campaign was widespread with each of the 3 key campaign slogans having been heard by at least 67% of respondents. Awareness of 2 specific campaign slogans was independently associated with an increased use of face coverings (aOR 2.31; p < 0.0001) and vaccine acceptance (aOR 2.36; p < 0.0001). Respondents reported receiving information on the pandemic from a wide range of sources with mobile phones and radio the most common. Trust in different sources ranged widely.

How Well the Constructs of Health Belief Model Predict Vaccination Intention: A Systematic Review on COVID-19 Primary Series and Booster Vaccines

This systematic review synthesizes the findings of quantitative studies examining the relationships between Health Belief Model (HBM) constructs and COVID-19 vaccination intention. We searched PubMed, Medline, CINAHL, Web of Science, and Scopus using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and identified 109 eligible studies. The overall vaccination intention rate was 68.19%. Perceived benefits, perceived barriers, and cues to action were the three most frequently demonstrated predictors of vaccination intention for both primary series and booster vaccines. For booster doses, the influence of susceptibility slightly increased, but the impact of severity, self-efficacy, and cues to action on vaccination intention declined. The impact of susceptibility increased, but severity's effect declined sharply from 2020 to 2022. The influence of barriers slightly declined from 2020 to 2021, but it skyrocketed in 2022. Conversely, the role of self-efficacy dipped in 2022. Susceptibility, severity, and barriers were dominant predictors in Saudi Arabia, but self-efficacy and cues to action had weaker effects in the USA. Susceptibility and severity had a lower impact on students, especially in North America, and barriers had a lower impact on health care workers. However, cues to action and self-efficacy had a dominant influence among parents. The most prevalent modifying variables were age, gender, education, income, and occupation. The results show that HBM is useful in predicting vaccine intention.