Use of a choice survey to identify adult, adolescent and parent preferences for vaccination in the United States

Understanding barriers to vaccination against invasive meningococcal disease: a survey of the knowledge gap and potential solutions

INTRODUCTION

Invasive meningococcal disease (IMD) is a leading cause of life-threatening bacterial meningitis and septicemia. Evidence points to a knowledge gap among parents, teenagers, and healthcare providers (HCPs) regarding IMD and available vaccines, including those against the highly prevalent serogroup B.

AREAS COVERED

An online survey was conducted between March 27 and April 12, 2019, to gather insights into the knowledge that parents/guardians have about IMD vaccines. The children were aged 2 months-10 years in Australia, Brazil, Germany, Greece, Italy, and Spain, 5-20 years in the UK, and 16-23 years in the US. The findings were discussed in the context of the available literature and solutions were proposed to minimize the knowledge gap and the barriers to vaccination against IMD.

EXPERT OPINION

The survey demonstrated that parents have a good understanding of IMD but a limited understanding of the different serogroups and vaccines. The available literature highlighted multiple barriers to IMD vaccine uptake; these may be reduced through education of HCPs, clear recommendations to parents by HCPs, the use of technology, and disease-awareness initiatives that engage parents through physical and digital channels. Further studies are warranted to assess the impact of the COVID-19 pandemic on IMD vaccination.

Intestinal response of mussels to nano-TiO2 and pentachlorophenol in the presence of predator

With the development of industry, agriculture and intensification of human activities, a large amount of nano-TiO₂ dioxide and pentachlorophenol have entered aquatic environment, causing potential impacts on the health of aquatic animals and ecosystems. We investigated the effects of predators, pentachlorophenol (PCP) and nano titanium dioxide (nano-TiO₂) on the gut health (microbiota and digestive enzymes) of the thick-shelled mussel Mytilus coruscus. Nano-TiO₂, as the photocatalyst for PCP, enhanced to toxic effects of PCP on the intestinal health of mussels, and they made the mussels more vulnerable to the stress from predators. Nano-TiO₂ particles with smaller size exerted a larger negative effect on digestive enzymes, whereas the size effect on gut bacteria was insignificant. The presence of every two of the three factors significantly affected the population richness and diversity of gut microbiota. Our findings revealed that the presence of predators, PCP, and nano-TiO₂ promoted the proliferation of pathogenic bacteria and inhibited digestive enzyme activity. This research investigated the combined stress on marine mussels caused by nanoparticles and pesticides in the presence of predators and established a theoretical framework for explaining the adaptive mechanisms in gut microbes and the link between digestive enzymes and gut microbiota.

A Discrete Choice Analysis Comparing COVID-19 Vaccination Decisions for Children and Adults

IMPORTANCE

COVID-19 vaccination rates in the US remain below optimal levels. Patient preferences for different attributes of vaccine products and the vaccination experience can be important in determining vaccine uptake decisions.

OBJECTIVE

To assess preferences for attributes of adult and pediatric COVID-19 vaccination among US adults.

DESIGN, SETTING, AND PARTICIPANTS

An online survey of a national panel of 1040 US adults was conducted in May and June 2021. A discrete choice analysis was used to measure the relative value of each attribute in the decision to choose a COVID-19 vaccination option for adults or children. Six attributes were used to described hypothetical vaccination options: vaccine effectiveness, mild side effects, rare adverse events, number of doses, time required for vaccination, and regulatory approval. Respondents chose between hypothetical vaccination profiles or no vaccination. Additional survey questions asked about vaccination beliefs, COVID-19 illness experience, COVID-19 risk factors, vaccination status, and opinions about the risk of COVID-19.

EXPOSURES

Respondents chose which vaccine profile they would prefer to receive for themselves (or no vaccination). Respondents then considered an identical set of profiles for a hypothetical child aged 0 to 17 years.

MAIN OUTCOMES AND MEASURES

Relative value of vaccination-related attributes were estimated using Bayesian logit regression. Preference profiles for subgroups were estimated using latent class analyses.

RESULTS

A total of 1040 adults (610 [59%] female; 379 participants [36%] with an age of 55 years and older years) responded to the survey. When asked about vaccination choices for themselves, participants indicated that vaccine effectiveness (95% vs 60%) was a significant attribute (β, 9.59 [95% CrI, 9.20-10.00] vs β, 0.41 [95% CrI, 0-0.80]). Respondents also preferred fewer rare adverse events (β, 6.35 [95% CrI, 5.74-6.86), fewer mild side effects (β, 5.49; 95% CrI, 5.12-5.87), 1 dose (β, 5.41; 95% CrI, 5.04-5.78), FDA approval (β, 6.01; 95% CrI, 5.64-6.41), and shorter waiting times (β, 5.67; 95% CrI, 4.87-6.48). Results were very similar when framing the question as adult or child vaccination, with slightly stronger preference for fewer rare adverse events for children. Latent class analysis revealed 4 groups of respondents: (1) individuals sensitive to safety and regulatory status, (2) individuals sensitive to convenience, (3) individuals who carefully considered all attributes in making their choices, and (4) individuals who rejected the vaccine.

CONCLUSIONS AND RELEVANCE

In this survey study of US adults, the identification of 4 distinct preference groups provides new information to guide communications to support vaccine decision making. In particular, the group that prioritize convenience (less time required for vaccination and fewer doses) may present an opportunity to create actionable strategies to increase vaccination uptake for both adult and pediatric populations.

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.

The Youth Attitudes about Vaccines (YAV-5) scale: adapting the parent attitudes about childhood vaccines short scale for use with youth in German, French, and Italian in Switzerland, exploratory factor analysis and mokken scaling analysis

No validated measures of vaccine hesitancy (VH) for youth vaccination currently exist. We adapted the Parent Attitudes about Childhood Vaccines survey (PACV-15) for use in youth to create the version Youth Attitudes about Vaccines survey (YAV-14 and YAV-5), then translated it into three languages (German, French, and Italian). We administered the YAV-14 to 1,003 youth aged 15-26 years in Switzerland. We used exploratory factor analysis and Mokken scale analysis to explore the psychometric properties, Cronbach's alpha to investigate the reliability for the YAV-14 and the YAV-5, but we only report results of the YAV-5 analysis here. We determined construct validity by logistic regression of the association between youth VH as measured by the YAV-5 and non-receipt of the first human papillomavirus (HPV) vaccine dose. EFA produced a single scale in German and French while two factors were obtained in Italian. All language versions fit the Mokken scale models with medium-scale strength. There was a significant association between VH and HPV vaccine non-receipt for the full sample (odds ratio (OR); 1.93, 95% confidence interval (CI); 1.31-2.85). Language-stratified analyses found a significant association between VH and non-immunization in the German-language sample. Our results demonstrate that the German version of YAV-5 is a valid and reliable scale for identifying vaccine hesitant youth regardless of sex, and the French version is a valid and reliable scale for identifying vaccine hesitant female youth. Further validation is needed for Italian and French-speaking male youth.

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

Vaccine hesitancy (VH) in the age of adolescence is a major public health issue, though it has not been widely examined in the scientific literature. This systematic review aims to address the determinants of VH among adolescents aged 10-19. PubMed, Scopus, and Web of Science were searched from the inception until 11 December 2020. Articles in English, assessing adolescents' attitudes toward vaccination in terms of hesitancy and/or confidence were considered eligible. Out of 14,704 articles, 20 studies were included in the qualitative analysis. Quality assessment was performed through the Appraisal tool for Cross-Sectional Studies (AXIS). A better knowledge of vaccine-preventable diseases, a higher confidence in vaccines, as well as an active involvement in the decision-making process showed a positive relationship with adolescents' vaccine uptake. These aspects should be considered to plan tailored interventions for the promotion of vaccination among adolescents and to reduce VH. Major limitations of this review are represented by the high heterogeneity of the tools used in the primary studies and the lack of standardization in outcomes definitions. Future research is needed to disentangle the interrelationship among the different determinants of VH in this age group.

Preferences for herpes zoster vaccination among adults aged 50 years and older in the United States: results from a discrete choice experiment

BACKGROUND

Most adults, and disproportionately fewer African-Americans, have not received herpes zoster (HZ) vaccination despite current recommendations. This study (GSK study identifiers: 208677/HO-17-18066) assessed HZ vaccination preferences among adults aged ≥ 50 years.

RESEARCH DESIGN AND METHODS

In this discrete choice experiment, respondents chose among a 'no vaccine' option and two HZ vaccine profiles, characterized by seven attributes, in a series of choice questions. Random-parameters logit results were used to predict likely vaccine uptake. Subgroup and latent class analysis of African-American's preferences were performed.

RESULTS

The preference weight for choosing HZ vaccines over no vaccine was statistically significant among the 1,454 respondents (71.9% whites; 25.2% African-Americans). Out-of-pocket (OOP) cost and vaccine effectiveness (VE) were the most important attributes. The African-American and the non-African-American subgroups had statistically significant differences in preferences (χ² = 59.91, p < 0.001), mainly driven by OOP cost and VE. Latent class analysis identified three groups of African-American respondents with systematically different preferences; two comprised likely-vaccinators, with one being more cost sensitive at lower price thresholds, and one likely non-vaccinators.

CONCLUSIONS

For all respondents, HZ vaccine choices were most sensitive to total OOP cost, followed by VE.

Vaccine Hesitancy and Rejection of a Vaccine for the Novel Coronavirus in the United States

The arrival of the COVID-19 vaccine has been accompanied by increased discussion of vaccine hesitancy. However, it is unclear if there are shared patterns between general vaccine hesitancy and COVID-19 vaccine rejection, or if these are two different concepts. This study characterized rejection of a hypothetical COVID-19 vaccine, and compared patterns of association between general vaccine hesitancy and COVID-19 vaccine rejection. The survey was conducted online March 20-22, 2020. Participants answered questions on vaccine hesitancy and responded if they would accept the vaccine given different safety and effectiveness profiles. We assessed differences in COVID-19 rejection and general vaccine hesitancy through logistic regressions. Among 713 participants, 33.0% were vaccine hesitant, and 18.4% would reject a COVID-19 vaccine. Acceptance varied by effectiveness profile: 10.2% would reject a 95% effective COVID-19 vaccine, but 32.4% would reject a 50% effective vaccine. Those vaccine hesitant were significantly more likely to reject COVID-19 vaccination [odds ratio (OR): 5.56, 95% confidence interval (CI): 3.39, 9.11]. In multivariable logistic regression models, there were similar patterns for vaccine hesitancy and COVID-19 vaccine rejection by gender, race/ethnicity, family income, and political affiliation. But the direction of association flipped by urbanicity (P=0.0146, with rural dwellers less likely to be COVID-19 vaccine rejecters but more likely to be vaccine hesitant in general), and age (P=0.0037, with fewer pronounced differences across age for COVID-19 vaccine rejection, but a gradient of stronger vaccine hesitancy in general among younger ages). During the COVID-19 epidemic’s early phase, patterns of vaccine hesitancy and COVID-19 vaccine rejection were relatively similar. A significant minority would reject a COVID-19 vaccine, especially one with less-than-ideal effectiveness. Preparations for introducing the COVID-19 vaccine should anticipate substantial hesitation and target concerns, especially among younger adults.

A clinical update on vaccines: focus on determinants of under-immunization and special considerations for adolescents

PURPOSE OF REVIEW

The current article reviews recent literature related to pediatric and adolescent vaccination, specifically focusing on social determinants of under-immunization, expanding adolescent immunization rates, and new recommendations surrounding the meningococcal serotype B vaccine (MenB).

RECENT FINDINGS

Vaccine refusals and vaccine-preventable diseases have been rising in some parts of the world, and appear to be linked to household factors, such as a family's socioeconomic status. Adolescents have lower immunization rates than younger children. Newer vaccines targeted at adolescents, such as the MenB vaccine, have yet to be widely accepted by pediatric providers, parents, and patients.

SUMMARY

Pediatric healthcare providers should attempt to increase local immunization rates by vaccinating children at all eligible office visits and utilizing electronic health record decision-support tools. Although the number of families who choose not to vaccinate their children may be rising, providers can be innovative (e.g. incorporate digital vaccine reminder systems) and increase their familiarity with new vaccine recommendations to continue to prevent serious vaccine-preventable diseases.