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An examination of age and sex or gender (sex/gender) in HIV vaccine preparedness studies can contribute to an understanding of these demographic variables in preparation for actual HIV vaccine trials. In this descriptive review, age and sex or gender (sex/gender) were examined in relation to willingness to participate (WTP) and retention in an HIV vaccine trial. Twenty-five articles were retrieved from the Organization for Economic Co-operation and Development (OECD) countries and 28 articles were retrieved from the non-OECD countries. In US studies that involved mainly white MSM, older men were more likely to be WTP in a hypothetical HIV vaccine trial and more likely to be retained than younger men. In most OECD studies, sex/gender was not associated with WTP in a hypothetical HIV vaccine trial, while females were more likely to be retained in most studies. Largely, age was not associated with WTP in the non-OECD countries, but the results on sex/gender were more variable. The relationship between adolescent or adult WTP in hypothetical HIV vaccine trials in South Africa did not appear to be modified by high school student status. In addition, more studies in discordant couples in the context of HIV vaccine preparedness could be conducted to examine gender roles and inequalities in preparation for HIV vaccine trials.

Introduction Racial/ethnic minorities are underrepresented in actual HIV vaccine trials in North America, and willingness to participate (WTP) and retention in an HIV vaccine trial may differ from that in Whites. Methods In this review, the authors identified HIV vaccine preparedness studies (VPS) in North America in high-risk populations that examined the relationship between race/ethnicity and WTP in a preventive phase 3 HIV vaccine trial, and the relationship to retention. Studies were categorized by risk group, and comparison group (Whites vs. non-Whites). Other types of trials of biomedical prevention were also identified, and WTP and retention rates were compared and contrasted to actual HIV vaccine trials. Results In the studies identified, WTP in a hypothetical trial HIV vaccine trial did not differ by race/ethnicity. In contrast, actual HIV vaccine trials, an HIV acquisition trial, and a phase 2B preexposure prophylaxis (PrEP) trial have enrolled a large percentage of White men. Human papilloma virus (HPV) privately-funded trials have also enrolled a large number of Whites, due to convenience sampling. Retention in the HIV acquisition trial was lower in African-Americans compared with Whites. Conclusion Strategies to increase WTP and enhanced retention (ER) strategies may help in recruiting and retaining minority participants in actual HIV vaccine trials and other trials of biomedical prevention.

The Health Belief Model provides a framework to understand motivators for volunteering for medical research. Motivators can take the form of social and personal benefits. In this systematic review of review articles, we contrast motivators of participation in actual cancer trials to those in actual HIV vaccine trials. We retrieved eight review articles from 2000 to 2012 examining motivators to participation in actual cancer trials. Personal benefits were most often psychological in nature, such as "coping with symptoms." Social benefits included "advancing research," "helping other cancer patients," and "for their family." While specific motivators vary between considerations - cancer research and HIV vaccine trials, these motivators fall into similar categories at similar frequencies. For example, personal/psychological benefits are common in each. Participant recruitment must be mindful of these categories of motivators for both cancer and HIV vaccine research.

An examination of actual HIV vaccine trials can contribute to an understanding of motivators for participation in these studies. Analysis of these motivators reveals that they can be categorized as social and personal benefits. Social benefits are generally altruistic, whereas personal benefits are psychological, physical, and financial. In this systematic review, the authors performed a literature search for actual preventive HIV vaccine trials reporting motivators to participation. Of studies conducted in the Organization for Economic Co-operation and Development (OECD) countries, the authors retrieved 12 studies reporting on social benefits and seven reporting on personal benefits. From the non-OECD countries, nine studies reported on social benefits and eight studies on personal benefits. Social benefits were most frequently described on macroscopic, altruistic levels. Personal benefits were most frequently psychological in nature. Rates of participation were compared between the OECD and the non-OECD countries. Knowledge of actual motivators in specific countries and regions can help target recruitment in various types of actual HIV vaccine trials.

There are gaps in our knowledge of the role cognitive factors play in determining people's willingness to participate (WTP) in therapeutic HIV vaccine trials. Using a cross-sectional study of HIV-positive injection drug users (IDU), we determined the role of three cognitive factors: HIV treatment optimism, self-efficacy beliefs, and knowledge of vaccine trial concepts in relation to WTP in a hypothetical phase 3 therapeutic HIV vaccine trial. WTP was 54%. Participants tended to be low in HIV treatment optimism (mean = 3.9/10), high in self-efficacy (mean = 79.8/100), and low in knowledge (mean = 4.1/10). Items pertaining to HIV treatment optimism and knowledge of HIV vaccine trial concepts were generally unrelated to WTP. An increase in self-efficacy had a statistically significant positive association with WTP (OR = 1.61, 95% CI = 1.04-2.46, p 0.05). Furthermore, most of these HIV-positive participants had high levels of self-efficacy, so we are most confident about this relationship at such levels. These findings indicate that interventions focused on increasing self-efficacy could enhance WTP among HIV-positive IDU.

Barriers to participation in an HIV vaccine trial have been examined in many HIV vaccine preparedness studies (VPS). These barriers can be understood in terms of the locus of the barrier (personal vs. social) and the nature of the barrier (risk vs. cost). Another type of barrier is perceived misconceptions. In this systematic review, we categorize barriers, and compare these barriers between the Organization for Economic Co-operation and Development (OECD) countries and the non-OECD countries. In the OECD countries, we retrieved 25 studies reporting personal risks (PR), 9 studies reporting social risks (SR), 10 studies reporting personal costs (PC), and 16 studies reporting misconceptions. In the non-OECD countries, we retrieved 27 studies reporting PR, 19 studies reporting SR, 18 studies reporting PC, 1 study reporting social costs (SC), and 13 studies reporting misconceptions. Important PR were "adverse effects" and "vaccine-induced seropositivity", "distrust of institutions", and "temptation to have unsafe sex" in men who have sex with men (MSM). "Discrimination" was a common SR. "Time commitment" was an important PC, and "family commitments" were a SC in one non-OECD country. "HIV infection from the vaccine" was a common misconception. Both the OECD and the non-OECD countries have similar barriers, and people's decisions to participate in a clinical trial involve multiple barriers. However, these barriers apply to hypothetical HIV vaccine trials, and barriers for actual vaccine trials need further assessment.

HIV vaccine preparedness studies (VPS) are important precursors to HIV vaccine trials. As well, they contribute to an understanding of motivators and barriers for participation in hypothetical HIV vaccine trials. Motivators can take the form of altruism and a desire for social benefits. Perceived personal benefits, including psychological, personal, and financial well-being, may also motivate participation. The authors performed a systematic review of HIV VPS using the Cochrane Database for Systematic Reviews, Medline, PubMed, Embase, and Google Scholar. The authors independently searched the literature for individual HIV VPS that examined motivators of participation in a hypothetical HIV vaccine trial, using the same search strategy. As the denominators employed in the literature varied across studies, the denominators were standardized to the number of respondents per survey item, regardless of their willingness to participate (WTP) in an HIV vaccine trial. The authors retrieved eight studies on social benefits (i.e., altruism) and 11 studies on personal benefits conducted in the Organization for Economic Co-operation and Development (OECD) countries, as well as 19 studies on social benefits and 20 studies on personal benefits in the non-OECD countries. Various different forms of altruism were found to be the major motivators for participation in an HIV vaccine trial in both the OECD and the non-OECD countries. In a large number of studies, protection from HIV was cited as a personal motivator for participation in a hypothetical HIV vaccine trial in the OECD and the non-OECD countries. Knowledge of motivators can inform and target recruitment for HIV vaccine trials, although it must be remembered that hypothetical motivators may not always translate into motivators in an actual vaccine trial.

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.

Educational level, employment, and income are key components of socioeconomic status (SES). This article is a systematic review of SES variables in North American countries, and their relationship to willingness to participate (WTP) and retention in a hypothetical preventive phase 3 HIV vaccine trial and in actual HIV vaccine trials. Men who have sex with men (MSM) tended to have higher educational levels, be more employed, and had higher income levels than injection drug users (IDU) and women at heterosexual risk (WAHR). In large part, there was no relationship between educational level and WTP, as well as between educational level and retention. Similarly, there was no relationship between employment and WTP. In WAHR who were African-American, those employed were less likely than others to complete the study at 18 months. The exact occupations of participants analyzed have not been specified, and specification of these occupations may help determine whether enhanced retention (ER) strategies are required.

Cognitive barriers to participation in actual HIV vaccine trials have not been previously comprehensively reviewed. In this review article, barriers in actual early phase, phase 2B, and phase 3 HIV vaccine trials are quantified and categorized, and compared between the Organization for Economic Co-operation and Development (OECD) countries and the non-OECD countries. Participation rates were standardized to allow for comparisons. In both the OECD and the non- OECD countries, barriers included subjective norms and discrimination, vaccine safety concerns, and logistical concerns. More actual HIV vaccine trials can incorporate questions about and quantify barriers to participation, and this may aid future recruitment strategies.

HIV vaccine development remains an urgent priority. Vaccine preparedness studies to assess feasibility are an important precursor to HIV vaccine trials. Studies such as these have taken place in many non-Organization for Economic Co-operation and Development (non-OECD) countries using diverse cohorts. This article is a systematic review of retention rates and willingness to participate (WTP) in HIV vaccine trials. Studies took place in Brazil, the Democratic Republic of Congo, Haiti, India, Russia, Thailand, and several sub-Saharan African countries. Studies generally reported recruitment of high-risk individuals. Of 33 studies we identified, retention was assessed in 16 studies, and the 12-month retention ranged from 77 to 85%. Willingness to participate was assessed in 21 studies. Willingness to participate ranged from 23 to 100%, and increased knowledge was associated with an increased WTP. Vaccine preparedness studies have taken place using diverse cohorts in the non-OECD countries. In general, retention rates and WTP have been adequate to conduct HIV vaccine trials. Educational programs to improve knowledge about HIV vaccines may contribute to better follow-up and an increased WTP in these countries.