Predicting hypothetical willingness to participate (WTP) in a future phase III HIV vaccine trial among high-risk adolescents

Health Communication and Decision Making about Vaccine Clinical Trials during a Pandemic

The COVID-19 pandemic has magnified the importance of clinical trials for finding a safe and effective vaccine to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19. Although communication about vaccines and vaccine hesitancy were challenges long before COVID-19, the twin facts of a pandemic and an "infodemic" of health information, misinformation, and disinformation have raised new challenges for vaccine-related communication and decision-making. The goal of this commentary is to highlight strategies to improve communication and decision-making for adults considering participation in COVID-19 vaccine clinical trials. First, I present a general conceptual model for clinical trial participation that can be applied to various vaccine and other clinical trial contexts. Next, I introduce the ASK (Assume, Seek, Know) approach for enhancing clinical trial participation: (1) assume that all patients will want to know their options, (2) seek the counsel of stakeholders, and (3) know your numbers. The ideas presented in this commentary are intended to enhance vaccine-specific clinical trial communication, decision-making, and literacy, while dually offering strategies and resources that may help reduce vaccine hesitancy and increase vaccine uptake over time.

Adolescent and Parent Perceptions about Participation in Biomedical Sexual Health Trials

Given the burden of HIV and other sexually transmitted infections among adolescents who are legal minors, it is critical that they be included in biomedical sexual health trials to ensure that new prevention and treatment interventions are safe, effective, and acceptable for their use. However, adolescents are often not well represented in clinical trials. We provide an overview of the available evidence regarding adolescent and parent willingness for adolescents to participate in biomedical sexual health trials, parental involvement in the permission-consent process, management of differences and discord among adolescents and parents, and parental involvement throughout the study period. We also outline recommendations for current practice and areas for future research.

Adolescents and Their Parents Differ on Descriptions of a Reproductive Health Study

STUDY OBJECTIVE

To understand how adolescents and parents describe a sexually transmitted infection prevention study to a friend.

DESIGN

Adolescents and parents participating in a study about willingness to participate in a hypothetical microbicide clinical trial were interviewed separately and asked to describe the clinical trial to a friend. Qualitative responses were written down verbatim and coded using a thematic framework analysis.

SETTING

Adolescent medicine clinics in New York City.

PARTICIPANTS

The participants consisted of adolescents, 14-17 years old, and a parent (n = 301 dyads) who spoke English or Spanish. Most adolescents (72%) identified as Hispanic and 65% reported minimal sexual experience (ie, nothing more than kissing).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Qualitative responses were content coded for: (1) overall approach; (2) opinion rendered; and (3) details mentioned using thematic framework. The relationship of demographic characteristics, sexual history, and recruitment method to how adolescents and/or parents described the study was evaluated.

RESULTS

Adolescents (n = 293) differed from parents (n = 298) in their overall approach to describing the study (P < .01) with more adolescents than parents providing a "purpose with detail" (54% adolescents vs 31% parents) and less providing a "commentary" description (6% adolescents vs 28% parents). Fewer adolescents (25% of n = 301) provided an opinion compared with parents (75% of n = 301; P < .01). A greater proportion of adolescents (70% adolescents, n = 206; vs 48% parents, n = 144) provided a detail (P < .01). Adolescents provided a greater number of details than parents (P < .01).

CONCLUSION

Adolescents in this sample were more focused on the details of the study. Parents were focused on their impression of the study. Adolescents and parents might need to be approached differently about reproductive health studies.

An update on human immunodeficiency virus vaccine preparedness studies

Human immunodeficiency virus (HIV) vaccine preparedness studies (VPSs) have taken place in both the Organisation for Economic Co-operation and Development (OECD) countries and the non-OECD countries. HIV VPSs are conducted to assess the feasibility of phase 3 HIV vaccine trials. This descriptive review is an update of HIV VPSs in the non-OECD countries, and examines the willingness to participate (WTP) in hypothetical HIV vaccine trials, as well as retention. Few VPSs have been published in the OECD countries since the discontinuation of the STEP/Phambili HIV vaccine trials. Barriers to participation in the non-OECD countries after the STEP/Phambili studies include safety issues and side effects, vaccine-induced seropositivity (VISP) and mistrust among key informants (KIs). HIV VPSs indicate that HIV vaccine trials are still feasible in the non-OECD countries, but barriers must be overcome to improve feasibility. Hypothetical WTP in a VPS may not translate into actual WTP in an HIV vaccine trial.

Preventive misconception and adolescents' knowledge about HIV vaccine trials

OBJECTIVE

Adolescents have had very limited access to research on biomedical prevention interventions despite high rates of HIV acquisition. One concern is that adolescents are a vulnerable population, and trials carry a possibility of harm, requiring investigators to take additional precautions. Of particular concern is preventive misconception, or the overestimation of personal protection that is afforded by enrolment in a prevention intervention trial.

METHODS

As part of a larger study of preventive misconception in adolescent HIV vaccine trials, we interviewed 33 male and female 16-19-year-olds who have sex with men. Participants underwent a simulated HIV vaccine trial consent process, and then completed a semistructured interview about their understanding and opinions related to enrolment in a HIV vaccine trial. A grounded theory analysis looked for shared concepts, and focused on the content and process of adolescent participants' understanding of HIV vaccination and the components of preventive misconception, including experiment, placebo and randomisation.

RESULTS

Across interviews, adolescents demonstrated active processing of information, in which they questioned the interviewer, verbally worked out their answers based upon information provided, and corrected themselves. We observed a wide variety of understanding of research concepts. While most understood experiment and placebo, fewer understood randomisation. All understood the need for safer sex even if they did not understand the more basic concepts.

CONCLUSIONS

Education about basic concepts related to clinical trials, time to absorb materials and assessment of understanding may be necessary in future biomedical prevention trials.

The HVTN503/Phambili HIV vaccine trial: a comparison of younger and older participants

By comparing younger to older participants enrolled in a HIV vaccine efficacy trial, we aimed to gain insights into the inclusion of adolescents in future trials. This was a sub-analysis of a multisite HIV vaccine randomized clinical trial in South Africa, conducted January-September 2007. Motivations for trial enrolment, social harms, adverse events and loss to follow-up were compared between younger (18-20 years old) and older participants (21-35 years old). Both younger (n = 238) and older participants (n = 563) were equally likely to report enrolling for altruistic reasons. Younger females were less likely than older participants to join for trial reimbursement (p = 0.005), while younger males were more likely to enrol because the vaccine may provide protection from HIV-acquisition (p < 0.001). There were no significant differences in the number of social harms reported. Compared to males over 20 years old, 18-20-year-old females were less likely to experience adverse events (OR = 0.1, CI 0.01-0.80) and no more likely to be lost to follow-up (OR = 0.7, CI 0.39-1.25), while 18-20-year-old males were no more likely to experience adverse events (OR = 1.3, CI 0.58-2.83) or loss to follow-up (OR = 0.8, CI 0.51-1.41). Our data support the inclusion of younger participants who are at risk for HIV in future HIV vaccine efficacy trials.

Willingness to participate in HIV vaccine efficacy trials among high risk men and women from fishing communities along Lake Victoria in Uganda

INTRODUCTION

HIV vaccine efficacy trials conducted in suitable populations are anticipated in sub-Saharan Africa. We assessed the willingness to participate in future vaccine trials among individuals from fishing communities along Lake Victoria, Uganda.

METHODS

From July to October 2012, we described a hypothetical vaccine trial to 328 (62.2% men) adults (18-49 years), at risk of HIV infection within 6 months of enrolment in a cohort and assessed their willingness to participate in the trial. Chi-square and logistic regression models were fitted to assess associations between vaccine trial attributes, participants' characteristics and willingness to participate.

RESULTS

Overall, 99.4% expressed willingness to participate in the hypothetical HIV vaccine trial. This decreased marginally with introduction of particular vaccine trial attributes. Delaying pregnancy for 10 months and large blood draw had the largest effects on reducing willingness to participate to 93.5% (p=0.02) and 94.5% (p=0.01) respectively. All the vaccine trial attributes in combination reduced willingness to participate to 90.6%. This overall reduction in willingness to participate was significantly associated with gender and exchange of gifts for sex in multivariable analysis; women were more than three times as likely to have expressed unwillingness to participate in future vaccine trials as men (aOR=3.4, 95% CI: 1.55, 7.33) and participants who never received gifts in exchange for sex were more than four times as likely to have expressed unwillingness as those who received gifts for sex (aOR=4.5; 95%CI 1.30, 16.70). The main motivators of participation were access to HIV counselling and testing services (31.9%), HIV education (18.0%), hope of being prevented from acquiring HIV (16.6%) and health care (12.5%).

CONCLUSION

Our study identifies an important population for inclusion in future HIV prevention trials and provides important insights into acceptability of trial procedures, differences in decisions of women and men and areas for further participant education.

Characteristics of female sex workers in southern India willing and unwilling to participate in a placebo gel trial

Respondent-driven sampling was used to recruit female sex workers (FSWs) for a community survey conducted in southern India. After survey completion, participants were given a brochure describing a clinical trial that entailed daily use of a placebo vaginal gel for four months. This study assessed predictors of screening among survey respondents, predictors of enrollment among those eligible for the trial, and predictors of visit attendance and retention among those enrolled. FSWs who reported having symptoms of sexually transmitted infections (STI), engaging in sex work in the past month, and living in a subdistrict easily accessible by public transportation with a high concentration of FSWs, were more likely to screen. FSWs who had never been tested for HIV were more likely to enroll. This analysis suggests that the primary reason FSWs participated in the trial was a desire for health care-not other factors hypothesized to be important, e.g., HIV risk perception and poverty status.

Socioecological influences on community involvement in HIV vaccine research

OBJECTIVE

This study investigated socioecological factors influencing HIV vaccine research participation among communities living in geographic areas with high HIV prevalence and high poverty rates.

METHODS

We surveyed a sample of 453 adults ≤18 years from areas of high poverty and high HIV prevalence in metro Atlanta and differentiated the effects of individual-, social/organizational-, and community-level characteristics on participation in HIV vaccine research via multilevel modeling techniques that incorporated questionnaire, program, and census data.

RESULTS

Models that adjusted for both individual-level covariates (such as race, gender, attitudes, and beliefs concerning HIV research), social/organizational- and community-level factors such as local HIV prevalence rates, revealed that the extent of HIV prevention-related programs and services in census tracts contributed to individuals' likelihood of participation in an HIV vaccine study. Additionally, neighborhood-based organizations offering HIV medical and treatment programs, support groups, and services (e.g., food, shelter, and clothing) encourage greater HIV vaccine research participation.

CONCLUSIONS

The findings support the hypothesis that community-level factors facilitate participation in HIV vaccine research independent of both individual- and social/organizational-level factors.

An extended model of reasoned action to understand the influence of individual- and network-level factors on African Americans' participation in HIV vaccine research

In the United States, the number and proportion of HIV/AIDS cases among black/African Americans continue to highlight the need for new biomedical prevention interventions, including an HIV vaccine, microbicide, or new antiretroviral (ARV) prevention strategies such as pre-exposure prophylaxis (PrEP) to complement existing condom usage, harm reduction methods, and behavioral change strategies to stem the HIV epidemic. Although black/African Americans are disproportionately impacted by HIV/AIDS, their participation in HIV clinical research continues to have unique challenges. We theorize that interaction among multilevel factors creates ideal alignment for minority participation in HIV clinical studies. Thus, we initially set out to test an extended model of reasoned action with 362 participants to understand the interplay of sociopsychological and network-level considerations influencing minority participation in HIV prevention research efforts. In this study, we linked the intrapersonal dimensions of attitudes, beliefs, and normative concerns to community-level components, appraisal of involvement with the clinical research organization, an entity which operates within a networked structure of community partner agencies, and identification with coalition advocacy aims. Various participatory outcomes were explored including involvement in future HIV vaccine community functions, participation in community promotion of HIV vaccine research, and community mobilization. Three-stage least squares estimates indicated similar findings across three models. Significant effects demonstrate the importance of positive attitudes toward HIV vaccine research, favorable health research beliefs, perceived social support for participation, HIV/AIDS issue engagement, and perceived relevance of the clinical research site's mission and values. Identification of these nuanced pathway effects provides implications for tailored community program development.

Cognitive factors and willingness to participate in an HIV vaccine trial among HIV-negative injection drug users

This cross-sectional study involving a cohort of injection drug users (IDU) examined the relationship between cognitive factors (HIV treatment optimism, self-efficacy and knowledge of vaccine trial concepts) as well as risk factors for seroconversion, and willingness to participate (WTP) in a preventive phase 3 HIV vaccine trial. Willingness to participate overall was 56%. In a multivariate analysis, for a 20-unit increase in a 100-point composite scale, self-efficacy was positively related to WTP (adjusted odds ratio [AOR]=1.95, 95% CI=1.40-2.70). HIV treatment optimism and knowledge of vaccine trial concepts were unrelated to WTP. Aboriginal ethnicity (AOR=3.47, 95% CI=1.68-7.18) and a higher educational level (>or=high school) (AOR=1.96, 95% CI=1.07-3.59) were positively related to WTP. This study provides information on WTP for an HIV vaccine trial. Limitations and future directions are also discussed.

Social and behavioral science in HIV vaccine trials: a gap assessment of the literature

Social and behavioral science research is integral to the conduct of HIV vaccine trials, especially because the vaccine targets an infection laden with sensitive human issues. Although social and behavioral sciences have played a larger role in HIV vaccine clinical trials than other vaccine clinical trials to date, this role should be expanded. Fortunately, related publications, conference coverage and research proposals are on the rise; community engagement is receiving more attention during the earlier stages of product development; and collaboration between HIV vaccine scientists and social and behavioral scientists is being fostered. Greater attention to social and behavioral science issues could not only facilitate accrual, but also improve research efficiency and relevance. In this review, gaps in the literature on social and behavioral science issues in HIV vaccine clinical research, including barriers and facilitators to trial participation, enhancing feasibility of trial success, health systems, policy and monitoring social and behavioral issues, are identified and directions are suggested for filling those gaps. Development of a safe, efficacious and acceptable HIV vaccine will be nurtured by addressing the gaps through interdisciplinary collaborations.