Understanding the determinants of vaccine hesitancy and vaccine confidence among adolescents: a systematic review

Operationalizing the Behaviour Change Wheel and APEASE criteria to co-develop recommendations with stakeholders to address barriers to school-based immunization programs

INTRODUCTION

School-based immunization programs offer an accessible route to routine vaccines for students. During the COVID-19 pandemic, school closures to comply with public health measures had a drastic effect on school-based immunization program delivery and associated vaccine uptake. We sought to integrate findings from a mixed methods study to co-develop evidence-based and theory-informed recommendations with a diverse group of stakeholders (i.e., decision makers, healthcare providers, school staff, parents and adolescent students) to address barriers to new and existing school-based immunization programs.

METHODS

Findings from a mixed methods study were integrated using a joint display and narrative summary. These findings were mapped through the Behaviour Change Wheel, a series of tools designed to facilitate the development of behaviour change interventions. Draft recommendations were provided to previous mixed methods study participants who consented to participating in future phases of the research study (n = 26). Feedback was captured using a Likert-scale survey of acceptability, practicality, effectiveness, affordability, safety and equity (APEASE) criteria, with feedback and additional insights captured using open-ended textboxes. Data was used to revise and finalize recommendations.

RESULTS

Applying the Behaviour Change Wheel, we drafted 26 evidence-based, theory-informed recommendations to address barriers to school-based immunization programs. Participants (n = 16) provided feedback, with half of the recommendations scoring 80% or higher across all six APEASE criteria. The remaining 13 recommendations received a moderate score across one or more criteria. Stakeholders identified a high level of interest in expanding the use of e-consent forms, expanding programming to offer a meningitis B vaccine, and recommendations to ease student anxiety.

CONCLUSION

We co-developed a range of recommendations to improve school-based immunization programs with stakeholders using data generated from a mixed methods study. Implementation of any single or combination of recommendations will need to be tailored to local clinic procedures, school system and health system resources.

Vaccine hesitancy in adolescents regarding COVID-19 vaccination: A literature review

BACKGROUND

Previous reviews on the cause of vaccine hesitancy (VH) have not included vaccine hesitancy related to the COVID-19 vaccination in adolescents, which is necessary for minimizing disruptions to education and the maintenance of their overall well-being, health, and safety. This review aims to provide an overview of vaccine-hesitant perspectives on the COVID-19 vaccination in adolescents and the factors that influence them.

METHODS

This review followed the Systematic Reviews and Meta-Analysis for Literature Review (PRISMA). Searches were carried out in the PubMed, Science Direct, and Google Scholar databases. Following data extraction, a thematic analysis of vaccine hesitancy in adolescents regarding COVID-19 vaccines was conducted.

RESULTS

Seven articles were included. Nine areas were identified as factors influencing vaccine hesitancy, namely gender identity, parental roles, vaccine safety and effectiveness, perceptions of COVID-19 as a disease, medical professionals' recommendations, health behavior, vaccination experience, adolescent ignorance, and religious concerns. Our findings suggest that the scientific knowledge of vaccines and the size of clinical trials during their development reduce vaccine hesitancy.

CONCLUSION

Our findings build on those of previous research to suggest specific information that may help address vaccine hesitancy among adolescents.

Building knowledge using a novel web-based intervention to promote HPV vaccination in a diverse, low-income population

OBJECTIVES

HPV vaccination rates remain suboptimal despite proven efficacy. Data suggest misconceptions or lack of knowledge are leading barriers. Our study aimed to develop and pilot a novel interactive education resource designed to educate parents and patients about HPV vaccines.

METHODS

This is a prospective pilot study conducted in an urban teaching hospital pediatric clinic. The Patient Activated Learning System (PALS) intervention included 3 web-based videos with HPV vaccine-related educational content. Participants were parents of adolescent patients, aged 11-17 years, and young adult patients, aged 18-26 years. Enrolled participants completed an HPV vaccine knowledge survey before and after watching PALS; paired scores were evaluated. Acceptability and participant-reported impact of PALS modules were measured via Likert-scale surveys.

RESULTS

132 individuals were approached; 101 (76%) enrolled and completed the study. Participants self-identified as Hispanic (50%), non-Hispanic Black (23%), non-Hispanic White (7%), Asian (6%), American/Alaskan/Hawaiian Native or Pacific Islander (5%). Half reported earning ≤$40,000 annually; 57% had only a high school education. Post-intervention knowledge scores were increased compared to baseline (9.87/27 points vs 17.53/27 points, p < 0.01). PALS modules were reported as enjoyable to use and understandable (89% and 93%, respectively), and improved participants' understanding of the importance of HPV vaccination (90%). Of the 18 patients unvaccinated at baseline, 39% received 1 shot of the HPV vaccine within one month.

CONCLUSION

The PALS HPV vaccine educational intervention was feasible, acceptable, and improved knowledge among a diverse, underserved population. Our intervention may positively influence HPV vaccination rates, with potential to overcome HPV vaccine hesitancy.

Changing epidemiology of COVID-19: potential future impact on vaccines and vaccination strategies

INTRODUCTION

COVID-19 was an unprecedented challenge worldwide; however, disease epidemiology has evolved, and COVID-19 no longer constitutes a public health emergency of international concern. Nonetheless, COVID-19 remains a global threat and uncertainties remain, including definition of the end of the pandemic and transition to endemicity, and understanding true rates of SARS-CoV-2 infection/transmission.

AREAS COVERED

Six international experts convened (April 2023) to interpret changing COVID-19 epidemiology and public health challenges. We report the panel's recommendations and knowledge gaps in COVID-19 epidemiology, SARS-CoV-2 evolution, and future vaccination strategies, informed by peer-reviewed publications, surveillance data, health authority assessments, and clinical experience.

EXPERT OPINION

High population SARS-CoV-2 immunity indicates the likely end to the pandemic's acute phase. Continued emergence of variants/sublineages that can evade the vaccine-induced antibody response are likely, but widespread immunity reduces the risk of disease severity. Continued surveillance is required to capture transition to endemicity, seasonality, and emergence of novel variants/sublineages, to inform future vaccination strategies. COVID-19 vaccination should be integrated into routine vaccination programs throughout life. Co-circulation with other respiratory viruses should be monitored to avoid a combined peak, which could overrun healthcare systems. Effective, combined vaccines and improved education may help overcome vaccine hesitancy/booster fatigue and increase vaccination uptake.

Lack of influence of social media on vaccine decision-making by university students in Ireland

Vaccine hesitancy is a complex, context-specific issue that negatively impacts vaccine uptake. During the COVID-19 pandemic, vaccine mis- and dis-information on social media negatively impacted on COVID-19 vaccine acceptance. University students' beliefs and behaviors surrounding vaccine decision-making is less studied, but this population is important in disease transmission, vaccine uptake and effectiveness. Here, we surveyed students in a third-level Irish university, in September 2022, when pandemic restrictions had been removed, to primarily determine if their use of, and influence by, mainstream and social media correlated with their willingness to receive a COVID-19 vaccine or any vaccine. We analyzed 151 responses and found no significant correlation between students' willingness to receive either a COVID-19 vaccine or any vaccine and their use of social media. There were significant links between vaccine acceptance and a range of factors, namely accommodation type, social media behaviors, perceived exposure to vaccine mis- or dis-information and previous vaccine uptake. This study provides a preliminary insight into drivers of university student COVID-19 and general vaccine willingness. It provides initial data, in the context of post-pandemic restrictions, to support further development of interventions to enhance vaccine uptake in third-level students in Ireland.

Can physicians and schools mitigate social inequalities in human papillomavirus vaccine awareness, uptake and vaccination intention among adolescents? A cross-sectional study, France, 2021 to 2022

BackgroundIn France, human papillomavirus (HPV) vaccination coverage varies across socioeconomic levels.AimWe aimed at assessing HPV vaccine awareness, uptake and vaccination intention among adolescents in France.MethodsIn a cluster-randomised study, 13-15-year-old students in 61 French middle schools completed a web-based questionnaire. We used multivariable logistic regression to evaluate determinants of HPV vaccine awareness, self-reported uptake and vaccination intention among unvaccinated students and interaction terms to explore effects of visits to family physician and remembering school lessons on vaccination. The French deprivation index of school municipalities served as proxy for socioeconomic levels.ResultsAmong 6,992 participants, awareness was significantly associated with parental education (odds ratio (OR) = 0.82; 95% confidence interval (CI): 0.71-0.95), language spoken at home (OR = 0.59; 95% CI: 0.52-0.66) and deprivation level (OR = 0.57; 95% CI: 0.44-0.71), regardless of physician visit or school lessons. Vaccine uptake was associated with parental education without a recent physician visit (OR = 0.31; 95% CI: 0.16-0.59, vs OR = 0.64; 95% CI: 0.52-0.78 with a visit, interaction p = 0.045). Vaccination intention among unvaccinated was associated with deprivation level (moderate-low vs low) among students not remembering school lessons on vaccination (OR = 0.17; 95% CI: 0.05-0.62, vs OR = 0.93; 95% CI: 0.51-1.67 remembering school lessons, interaction p = 0.022). Parental education was associated with vaccination intention among students reporting a physician visit (OR = 0.41; 95% CI: 0.26-0.64 vs OR = 1.05; 95% CI: 0.50-2.20 without a visit, interaction p = 0.034).ConclusionOur results suggest that healthcare and school could promote vaccination and mitigate social inequalities in HPV vaccination coverage.

Understanding Factors Contributing to Vaccine Hesitancy in a Large Metropolitan Area

Vaccine hesitancy has become a major global concern, leading to a significant decrease in the vaccination rate, with the World Health Organization recognizing it as one of the top ten threats to public health. Moreover, the health cost generated is evaluated to be 27 billion dollars per year in the US alone. To investigate the association between demographic variables and knowledge, attitudes, and behaviours related to vaccination, a survey-based cross-sectional study was conducted with 1163 individuals. Three models were used to perform a multiple linear regression analysis. In Model I, knowledge about vaccinations was found to be associated with smoking habits, education, and marital status. In Model II, attitudes towards vaccinations were significantly associated with sex, smoking habits, education, marital status, and knowledge. In Model III, behaviours related to vaccination were associated with sex, smoking habits, having children, knowledge, and attitudes. One potential solution to improve behaviours related to vaccinations in the general population is to implement specific public health programs, which can be a cost-effective intervention. This study provides valuable insights into the determinants of knowledge, attitudes, and behaviours related to vaccinations in the general population.

Unvaccinated Adolescents' COVID-19 Vaccine Intentions: Implications for Public Health Messaging

PURPOSE

COVID-19 vaccine uptake remains low for US adolescents and contributes to excess morbidity and mortality. Most research has assessed parental intention to vaccinate their children. We explored differences between vaccine-acceptant and vaccine-hesitant unvaccinated US adolescents using national survey data.

METHODS

A nonprobability, quota-based sample of adolescents, aged 13-17 years, was recruited through an online survey panel in April 2021. One thousand nine hundred twenty seven adolescents were screened for participation and the final sample included 985 responses. We assessed responses from unvaccinated adolescents (n = 831). Our primary measure was COVID-19 vaccination intent ("vaccine-acceptant" defined as "definitely will" get a COVID-19 vaccine and any other response classified as "vaccine-hesitant") and secondary measures included reasons for intending or not intending to get vaccinated and trusted sources of COVID-19 vaccine information. We calculated descriptive statistics and chi-square tests to explore differences between vaccine-acceptant and vaccine-hesitant adolescents.

RESULTS

Most (n = 831; 70.9%) adolescents were hesitant, with more hesitancy observed among adolescents with low levels of concern about COVID-19 and high levels of concern about side effects of COVID-19 vaccination. Among vaccine-hesitant adolescents, reasons for not intending to get vaccinated included waiting for safety data and having parents who would make the vaccination decision. Vaccine-hesitant adolescents had a lower number of trusted information sources than vaccine-acceptant adolescents.

DISCUSSION

Differences identified between vaccine-acceptant and vaccine-hesitant adolescents can inform message content and dissemination. Messages should include accurate, age-appropriate information about side effects and risks of COVID-19 infection. Prioritizing dissemination of these messages through family members, state and local government officials, and healthcare providers may be most effective.

Evaluation of the Knowledge and Attitude of Adolescents Regarding the HPV Infection, HPV Vaccination and Cervical Cancer in a Region from the Northwest of Romania

Purpose

In Romania, after reaching the age of 18, teenage girls can make an informed decision about vaccination. The aim of the study was to evaluate both knowledge and attitudes related to HPV infection, HPV vaccination, cervical cancer, as well as intentions, reservations, reasons that could influence the decision related to vaccination.

Patients and Methods

We applied an anonymized questionnaire to 690 teenage girls in the 18-19 age group, recruited from 15 high schools in Bihor County. Based on the answers to the question corresponding to item 14 of subscale 3, 2 groups were identified: the group with a hesitant behavior called the non-vaccine group (GNV) and the group with a positive behavior called the pro-vaccine group (GPV). The statistical analysis was processed by using IBM-SPSS 22.

Results

The analysis revealed significant differences between the groups in terms of the level of knowledge and attitudes related to vaccination, the adolescent girls in the GPV being more aware of the role and importance of HPV vaccination and more open to the idea of vaccination. For the GNV, the behavior can be explained by the fact that even if they have heard about the HPV infection being transmitted through unprotected sex and they think that vaccination in general is necessary to prevent certain diseases, they do not know if HPV vaccination would be effective in protecting them in the future. Adolescents from GPV declare they would accept HPV vaccination if it would be offered to them or they are already vaccinated.

Conclusion

Alongside interventions targeting parents and health-care professionals, it is necessary to improve the level of knowledge of adolescents about HPV infection, HPV vaccination and cervical cancer, by organizing information campaigns in schools, campaigns in which professionals in the field should be involved, but also by implementing education programs addressed to them.

Do social media interventions increase vaccine uptake?

Introduction

The Italian mass COVID-19 vaccination campaign has included children aged 5-11 years as part of the target population since December 2021. One of the biggest challenges to vaccine uptake was vaccine hesitancy among parents and children's caregivers. Primary care pediatricians (PCPs), as the first point of contact between the National Health Service (NHS) and parents/caretakers, initiated various communication strategies to tackle this hesitancy. This study aims to evaluate the impact of a PCP-led social media intervention and a digital reminder service (DRS) on parental hesitancy regarding vaccinating their 5-11-year-old children against COVID-19.

Methods

A prospective cohort study was designed, and the chosen target populations were parents and caretakers of children aged 5-11 years. Two PCP cohorts were recruited. The first group received a social media intervention and a DRS; while the second group did not. Both cohorts had access to traditional face-to-face and telephone-based counseling. The vaccination coverage rate in the two groups was evaluated.

Results

A total of 600 children were enrolled. The exposed cohort (277 patients) received social media intervention, DRS, and counseling options (face-to-face and telephone-based), whereas the non-exposed cohort (323 patients) received only counseling options. In total, 89 patients from the exposed cohort did not receive any dose of the COVID-19 vaccine (32.5%), 165 were fully immunized (59.5%), and 23 received only one dose (8.5%). A total of 150 non-exposed patients did not receive any dose of the COVID-19 vaccine (47%), 147 were fully immunized (45.5%), and 24 only received one dose (7.4%). The difference between the two groups was statistically significant (chi square = 11.5016; p = 0.0006).

Conclusion

Social media and DRS interventions had a positive impact on vaccine uptake and may be helpful in tackling vaccine hesitancy. Better-designed studies are needed to corroborate these findings.

Effects of a health psychology-based intervention for patients with asplenia on psychological determinants of preventive behaviour: A propensity score analysis

OBJECTIVE

Patients with asplenia have an increased lifelong risk of severe infections especially post splenectomy sepsis with hospital mortality rates of 30-50%. Adherence to existing guidelines for preventive measures is low. Objective of the study is the evaluation of a novel intervention to increase health psychological outcomes in patients with asplenia resulting in better adherence to preventive measures.

METHODS

The intervention was evaluated by conducting a prospective, two-armed historical control group design via propensity score analysis. Focus are health-psychological outcomes: self-efficacy, intention, risk perception, behaviour planning, self-management, health literacy, patient involvement and disease-knowledge.

RESULTS

Patients in the intervention group (N = 110) showed a higher increase in almost all outcomes compared to a historical control group (N = 115). The strongest increase was observed in "asplenia-specific self-management" (average treatment effect: ATE 1.14 [95% CI 0.91-1.36] p < .001) and "asplenia-specific health-literacy" (ATE 1.42 [95% CI 1.18-1.65] p < .001). Significant intervention effects were also found in behaviour planning, perceived involvement and disease-knowledge.

CONCLUSION

The patient-focused intervention is effective in improving health-psychological outcomes in patients with asplenia.

PRACTICE IMPLICATIONS

The implementation of the intervention can make an important contribution to care and lead to an improvement of health-psychological outcomes that may result in a higher adherence to prevention measures.

Adolescents' Opinions on COVID-19 Vaccine Hesitancy: Hints toward Enhancing Pandemic Preparedness in the Future

To understand and assess vaccine reluctance, it is necessary to evaluate people's perceptions and grasp potential reasons for generic apprehension. In our analysis, we focus on adolescents' impressions towards anti-vaxxer behavior. The aim of the study is to figure out students' opinions about vaccine reluctance, connecting possible explanations that motivate anti-vaxxer decisions with common specific personality traits. We further investigate people's forecasts concerning the evolution of the pandemic. Between 2021 and 2022, we conducted a randomized survey experiment on a sample of high school individuals (N=395) living in different Italian regions. At that time, the vaccination campaign had already been promoted for nearly one year. From the analysis, it emerges that vaccinated people (92%), especially males, tend to be more pessimistic and attribute a higher level of generic distrust in science to anti-vaxxers. The results show that family background (mother's education) represents the most influential regressor: individuals coming from less educated families are less prone to attribute generic distrust and distrust of vaccines as principal reasons for vaccine reluctance. Similarly, those who rarely use social media develop a minor tendency to believe in a generic pessimism of anti-vaxxers. However, concerning the future of the pandemic, they are less likely to be optimistic toward vaccines. Overall, our findings shed light on adolescents' perceptions regarding the factors that influence vaccine hesitancy and highlight the need for targeted communication strategies to improve vaccination rates.

Examining multilevel influences on parental HPV vaccine hesitancy among multiethnic communities in Los Angeles: a qualitative analysis

BACKGROUND

Human papillomavirus (HPV) vaccine hesitancy is a growing concern in the United States, yet understudied among racial/ethnic minority parents. We conducted qualitative research to understand parental HPV vaccine hesitancy and inform community-specific, multilevel approaches to improve HPV vaccination among diverse populations in Los Angeles.

METHODS

We recruited American Indian/Alaska Native (AI/AN), Hispanic/Latino/a (HL) and Chinese parents of unvaccinated children (9-17 years) from low-HPV vaccine uptake regions in Los Angeles for virtual focus groups (FGs). FGs were conducted in English (2), Mandarin (1), and Spanish (1) between June-August 2021. One English FG was with AI/AN-identifying parents. FGs prompted discussions about vaccine knowledge, sources of information/hesitancy, logistical barriers and interpersonal, healthcare and community interactions regarding HPV vaccination. Guided by the social-ecological model, we identified multilevel emergent themes related to HPV vaccination.

RESULTS

Parents (n = 20) in all FGs reported exposure to HPV vaccine information from the internet and other sources, including in-language media (Mandarin) and health care providers (Spanish). All FGs expressed confusion around the vaccine and had encountered HPV vaccine misinformation. FGs experienced challenges navigating relationships with children, providers, and friends/family for HPV vaccine decision-making. At the community-level, historical events contributed to mistrust (e.g., forced community displacement [AI/AN]). At the societal-level, transportation, and work schedules (Spanish, AI/AN) were barriers to vaccination. Medical mistrust contributed to HPV vaccine hesitancy across the analysis levels.

CONCLUSION

Our findings highlight the importance of multilevel influences on parental HPV vaccine hesitancy and decision-making and the need for community-specific messaging to combat medical mistrust and other barriers to HPV vaccination among racial/ethnic minority communities.

Not All Conservatives Are Vaccine Hesitant: Examining the Influence of Misinformation Exposure, Political Ideology, and Flu Vaccine Acceptance on COVID-19 Vaccine Hesitancy

Despite the mass availability of COVID-19 vaccines in the United States, many Americans are still reluctant to take a vaccine as an outcome from exposure to misinformation. Additionally, while scholars have paid attention to COVID-19 vaccine hesitancy, the influence of general vaccine hesitancy for important viruses such as the flu has largely been ignored. Using nationally representative data from Pew Research Center’s American Trends Panel survey (Wave 79), this study examined the relationship between perceived misinformation exposure, COVID-19 vaccine hesitancy, flu vaccine acceptance, political ideology, and demographic trends. The findings suggest that those who accepted the flu vaccine were less likely to be COVID-19 vaccine-hesitant. In addition, moderation analyses showed that perceived misinformation exposure increases COVID-19 vaccine hesitancy for conservatives and moderates but not for liberals. However, perceived misinformation exposure influences COVID-19 vaccine hesitancy among conservatives only if they are also flu vaccine-hesitant. Perceived misinformation exposure has no role in COVID-19 vaccine hesitancy if individuals (irrespective of political ideology) are regular with their flu vaccine. The results suggest that the effect of misinformation exposure on negative attitudes toward COVID-19 may be associated with generalized vaccine hesitancy (e.g., flu). The practical and theoretical implications are discussed.

Trust in scientists on COVID-19 vaccine hesitancy and vaccine intention in China and the US

When we recognize various factors which influence vaccine willingness, it is unclear whether these factors work the same in different countries. This study explored how trust in scientists was related to COVID-19 vaccine hesitancies and vaccine willingness in China and the U.S. We attempted to understand the extent to which the perceived trustworthiness of scientists would predict vaccine hesitancies and intention to get vaccinated differently in these two countries. An online survey with participants in China (N = 391) and in the U.S. (N = 363) was conducted. Participants were asked about their view of scientists' competence, benevolence, and integrity as dimensions of trustworthiness, three types of vaccine hesitancies, as well as their willingness to get vaccinated. The results showed that trust in scientists was negatively related to individual vaccine hesitancy in both China and the U.S., and trust was negatively associated with the level of contextual hesitancy and vaccine-specific hesitancy in the U.S. Higher trust in scientists was also associated with the willingness to get vaccines in the U.S., rather than in China. Results yielded differences in China and the U.S. in how trust in scientists and vaccine hesitancies predicted individuals' willingness to get vaccinated.

Understanding COVID-19 vaccine hesitancy: A cross-sectional study in Malang District, Indonesia

Introduction

Vaccine hesitancy could undermine efforts to reduce incidence of coronavirus disease 2019 (COVID-19). Understanding COVID-19 vaccine hesitancy is crucial to tailoring strategies to increase vaccination acceptance. This study aims to investigate the prevalence of and the reasons for COVID-19 vaccine hesitancy in Malang District, Indonesia.

Methods

Data come from a cross-sectional study among individuals aged 17-85 years old (N = 3,014). Multivariate ordered logistic regression was used to identify factors associated with postponing or refusing COVID-19 vaccines. The Oxford COVID-19 vaccine hesitancy scale was used to measure vaccine hesitancy. A wide range of reasons for hesitancy, including coronavirus vaccine confidence and complacency, vaccination knowledge, trust and attitude in health workers and health providers, coronavirus conspiracy, anger reaction and need for chaos, populist views, lifestyle, and religious influence, was examined.

Results and discussion

The results show that 60.2% of the respondents were hesitant to receive the COVID-19 vaccine. Low confidence and complacency beliefs about the vaccine (OR = 1.229, 95% CI = 1.195-1.264) and more general sources of mistrust within the community, particularly regarding health providers (OR = 1.064, 95% CI = 1.026-1.102) and vaccine developers (OR = 1.054, 95% CI = 1.027-1.082), are associated with higher levels of COVID-19 vaccine hesitancy. Vaccine hesitancy is also associated with anger reactions (OR = 1.019, 95% CI = 0.998-1.040), need for chaos (OR = 1.044, 95% CI = 1.022-1.067), and populist views (OR = 1.028, 95% CI = 1.00-1.056). The findings were adjusted for socio-demographic factors, including age, sex, education, marital status, working status, type of family, household income, religious beliefs, and residency. The results suggest the need for an effective health promotion program to improve community knowledge of the COVID-19 vaccine, while effective strategies to tackle "infodemics" are needed to address hesitancy during a new vaccine introduction program.

Knowledge, attitudes, and behaviors toward COVID-19 vaccination in a sample of Italian healthcare workers

Vaccine hesitancy in healthcare workers (HCWs) has been studied for various contagious diseases, but there is still insufficient knowledge about this phenomenon for COVID-19. We developed and validated a knowledge, attitude, and practice survey of 39 questions to assess Italian HCWs' hesitancy toward vaccination in general (general hesitancy), COVID-19 vaccination (COVID-19 hesitancy), and public health injunctive measures (refusal of obligations). The survey was administered through a web platform between July and November 2021. Three multivariable logistic regressions were performed to evaluate the association between the explored dimensions of hesitancy and the potential determinants investigated. Out of 2,132 respondents with complete answers, 17.0% showed to be generally hesitancy toward vaccination, 32.3% were hesitant on COVID-19 vaccination, while 18.8% were categorized as refusing obligations. A significant protective effect against all three dimensions of hesitancy was found for increasing fear of COVID-19, advising COVID-19 vaccination to relatives and patients, having received flu vaccination in the previous year and having higher levels of education. Better self-rated knowledge about COVID-19 vaccines and reading up institutional sources were significantly protective against general and COVID-19 hesitancy, while being a physician rather than another healthcare professional was protective only against COVID-19 hesitancy. Conversely, increasing age and referring to colleagues to expand knowledge about COVID-19 were positively associated with COVID-19 hesitancy. The determinants of general hesitancy, COVID-19 hesitancy and the refusal of obligations are mostly overlapping. Given the great influence they exert on patients and communities, it is pivotal to limit HCWs vaccine hesitancy through appropriate training activities.

Stated preferences for human papillomavirus vaccination for adolescents in selected communities in Ibadan, Southwest Nigeria: A discrete choice experiment

Administration of the human papillomavirus (HPV) vaccine in early adolescence is effective in preventing cervical cancer, a common cancer in sub-Saharan Africa. Nigeria is in the pre-introduction era of the HPV vaccine. Understanding the preferences of the population for the vaccine can help design the HPV immunization program to ensure high uptake of the vaccine. This study explored the preferences for the HPV vaccine among stakeholders in selected communities in Ibadan, Nigeria. A discrete choice experiment survey based on six attributes of the HPV vaccine (which were the number of doses, the efficacy of the vaccine, cost of the vaccine, location of the service point, other benefits of the vaccine apart from prevention of cervical cancer and the odds of a side effect from the vaccine) was carried out in five communities. Data were analyzed using conditional and mixed logit models. Seven hundred community members were recruited, 144 (20.7%) were adolescents and 248 (35.4%) were males. In line with expectations, respondents preferred vaccines with higher efficacy, less severe side effects and lower costs. Preference heterogeneity was identified for adolescents that were less price-sensitive and other community members who were less likely to prefer using schools as the service point. The high socioeconomic class preferred a vaccine that also prevents genital warts. There were variabilities in the preferences for the attributes of the HPV vaccine in the study communities. These variabilities need to be considered in the introduction of the HPV vaccine to ensure high uptake of the vaccine.

The Implementation and Impact of a Revised National Childhood Immunization Schedule in an Urban Asian Community

Changes to the national childhood immunization schedule (NCIS) can have a potential impact on vaccine uptake in the community. The NCIS in Singapore has undergone several revisions over the years, with the most recent modification on 1 November 2020. The new NCIS includes, as routine, the influenza and the varicella vaccine, as well as two combination vaccines, the measles, mumps, rubella and varicella vaccine (MMRV), and the hexavalent diphtheria, acellular pertussis, tetanus, haemophilus influenza b, injectable polio, and hepatitis B vaccine (6-in-1). This retrospective database study aims to assess the effect of the new NCIS on (a) the vaccination uptake of children at 6 and 12 months and (b) the cost difference to the healthcare system and to parents. One-year vaccination data from two cohorts of children immunized according to the old (n = 10,916) and new NCIS (n = 10,299) were extracted, respectively, from their electronic medical records. The vaccine uptake at 6 and 12 months increased by 10.8 and 2.1%, respectively, with the new NCIS as compared to the old NCIS. The mean number of required visits to the primary care clinic for each child was reduced from six to four. There is an estimated 6.41% cost reduction with the new NCIS.

Effect of a web-based cervical cancer survivor story on the willingness and behavioral change for Human Papillomavirus Vaccination among Japanese parents with at least one daughter aged 11 to 18 years old: Randomized Controlled Trial

Background

Providing adequate information to parents who have children eligible for human papillomavirus (HPV) vaccination is essential to overcoming vaccine hesitancy in Japan, where the government recommendation has been suspended. However, prior trials assessing the effect of brief educational tools have shown only limited effects on increasing the willingness of parents to vaccinate their daughters.

Objective

The aim of this trial is to assess the effect of a cervical cancer survivor’s story on the willingness of parents to get HPV vaccination for their daughters.

Methods

In this double-blinded, randomized controlled trial (RCT) implemented online, we enrolled 2175 participants aged 30-59 years in March 2020 via a webpage and provided them with a questionnaire related to the following aspects: awareness regarding HPV infection and HPV vaccination, and willingness for HPV vaccination. Participants were randomly assigned (1:1) to see a short film on a cervical cancer survivor or nothing, stratified by sex (male vs female) and willingness for HPV vaccination prior to randomization (yes vs no). The primary endpoint was the rate of parents who agreed for HPV vaccination for their daughters. The secondary endpoint was the rate of parents who agreed for HPV vaccination for their daughters and the HPV vaccination rate at 3 months. The risk ratio (RR) was used to assess the interventional effect.

Results

Of 2175 participants, 1266 (58.2%) were men and 909 (41.8%) were women. A total of 191 (8.8%) participants were willing to consider HPV vaccination prior to randomization. Only 339 (15.6%) participants were aware of the benefits of HPV vaccination. In contrast, 562 (25.8%) participants were aware of the adverse events of HPV vaccination. Although only 476 (21.9%) of the respondents displayed a willingness to vaccinate their daughters for HPV, there were 7.5% more respondents in the intervention group with this willingness immediately after watching the short film (RR 1.41, 95% CI 1.20-1.66). In a subanalysis, the willingness in males to vaccinate daughters was significantly higher in the intervention group (RR 1.50, 95% CI 1.25-1.81); however, such a difference was not observed among females (RR 1.21, 95% CI 0.88-1.66). In the follow-up survey at 3 months, 1807 (83.1%) participants responded. Of these, 149 (8.2%) responded that they had had their daughters receive vaccination during the 3 months, even though we could not see the effect of the intervention: 77 (7.9%) in the intervention group and 72 (8.7%) in the control group.

Conclusions

A cervical cancer survivor’s story increases immediate willingness to consider HPV vaccination, but the effect does not last for 3 months. Furthermore, this narrative approach to parents does not increase vaccination rates in children eligible for HPV vaccination.

Trial Registration

UMIN Clinical Trials Registry UMIN000039273; https://tinyurl.com/bdzjp4yf

Vaccine eagerness: A new framework to analyse preferences in single profile discrete choice experiments. Application to HPV vaccination decisions among French adolescents

Background

We previously conducted a single-profile discrete choice experiment to elicit preferences of adolescents around HPV vaccine communication, finding that only half of participants made variable choices (non-uniform respondents) from which preferences were elicited. In this paper we provide a framework to evaluate post-choice certainty information to elicit preferences even among respondents who uniformly accepted (serial demanders) or refused (serial non-demanders) hypothetical vaccination scenarios.

Methods

During an in-class online questionnaire among 1458 French adolescents aged 13–15 years old, we collected certainty levels (0–10) after decisions on nine hypothetical scenarios, including four vaccination attributes: information on vaccine-preventable disease type, on vaccine safety, on potential for indirect protection and on vaccine coverage. We developed a vaccine eagerness scale (ranging from −10 to 10), by combining information on the binary decision (accept vs. refuse the hypothetical vaccine) and the decision certainty level. We used random effects linear regressions to evaluate attributes’ impact on vaccine eagerness. Sensitivity analyses were performed taking into account low response quality, assessed as invariant certainty and low response time.

Results

Attributes’ impact on decision certainty were similar between serial demanders (N = 659) and non-uniform respondents (N = 711): mentioning a positive benefit-risk balance significantly decreased certainty to accept (coefficient −0.93), while information on 80% coverage in other countries (+0.33) and potential for disease elimination (+0.09) increased it. Among serial non-demanders, significant attribute impacts were observed only after exclusion of low-quality responses (N = 31): a potential for disease elimination (coefficient: +0.24) and 80% coverage in other countries (+0.42) significantly increased certainty of refusing vaccination. Combining decision and certainty into a vaccine eagerness indicator allowed analysing preferences in the full sample, including “hesitant” respondents, who were sensitive to the content of the vaccination profile.

Conclusion

Choice certainty informs on respondents’ preferences in single-profile discrete-choice experiments, in particular among those with uniform responses.

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Preferences are not identified among “uniform respondents” in single profile DCEs.

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Analysis of post-choice certainty can reveal information on their preferences.

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We propose a new concept for DCEs on vaccination, “vaccine eagerness”.

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Vaccine eagerness allows analyzing preferences among serial non-demanders.

What do adolescents think about vaccines? Systematic review of qualitative studies

Adolescence presents a key opportunity to build vaccine-related health literacy and promote vaccine confidence and uptake. Although adolescents are central to vaccination programs, their views around vaccines are frequently underrepresented in qualitative literature. We reviewed qualitative studies to systematically identify and summarize existing evidence on adolescents' own understanding of vaccines and experiences with vaccine decision-making, including self-consent when applicable. CINAHL; Embase; Ovid Medline; and Psych Info database searches were last updated on May 28, 2022. Data pertaining to general study characteristics, participant demographics, and qualitative content were extracted independently by two reviewers and analyzed using textual narrative synthesis. Out of 3559 individual records, 59 studies were included. The majority of the studies were conducted in high-income countries and 75% focused on human papilloma virus vaccines, with the remaining studies looking at COVID-19, meningococcal, hepatitis B and influenza vaccines or adolescent experiences with vaccines in general. Adolescent self-consent was explored in 7 studies. Perspectives from sexual and gender minorities were lacking across studies. Adolescents often had limited understanding of different vaccines and commonly perceived vaccine information to be directed towards their parents rather than themselves. Many adolescents felt school-based vaccine education and information available through healthcare providers were insufficient to make informed decisions about vaccines. While adolescents described obtaining vaccine information from traditional and online media, face-to-face interactions and opinions from trusted adults remained important. Adolescents generally relied on their parents for vaccine-decision making, even when self-consent was an option. A notable exception to this included marginalized adolescents who could not rely on parents for health-related advice. Qualitative literature about adolescent vaccines would be enriched by studies examining vaccines other than the HPV vaccine, studies examining adolescent vaccine programs in low and middle-income countries, and by deliberately eliciting vaccine experiences of adolescent with diverse sexual orientation and gender identities.

Vaccine Hesitancy and Trust in the Scientific Community in Italy: Comparative Analysis from Two Recent Surveys

Vaccination rates in Italy fell until 2015 because of unfounded safety concerns. Public education and a 2017 law on mandatory vaccination have boosted rates since then. The aim of our study is to explore how trust in the scientific community and attitudes towards vaccines have changed in the period of 2017-2019 in Italy. Data were extracted from the Italian section of the 2017 and 2019 editions of the European Social Survey (ESS). We compared the two surveys highlighting changes in public opinion on vaccines. A descriptive analysis of the socio-cultural variables according to the answers provided to key questions on the harmfulness of vaccines was conducted. Differences between percentages were tested by using the χ2 test. The association between the opinion about the harmfulness of vaccines and trust in the scientific community was analyzed through a logistic regression model. Compared to ESS8, ESS9 showed an increase in the percentage of respondents disagreeing with the harmfulness of vaccines. Trust in the scientific community raised in the period from 2017 to 2019 (59% vs. 69.6%). Higher education was significantly associated with disagreement regarding the harmfulness of vaccines (odds ratio (OR) = 2.41; 95% confidence interval (95%CI) 1.75-3.31), the strongest predictor was trust in the scientific community (OR = 10.47; 95% CI 7.55-14.52). In Italy, trust in the scientific community and in vaccinations has grown significantly in recent years, indicating a paradigm shift in public opinion compared to the past. Central actions and effective public communication strategies might reduce vaccine hesitancy and could be essential to garner public trust.