Challenges for HIV vaccine dissemination and clinical trial recruitment: if we build it, will they come?

Social Impacts Among Participants in HIV Vaccine Trial Network (HVTN) Preventive HIV Vaccine Trials

BACKGROUND

Given the persistent stigma and discrimination against HIV worldwide, preventive HIV vaccine trials face unique challenges. Negative social impacts (NSIs)-problems that HIV vaccine trial participants face in many different spheres of their lives related to trial participation-have received a great deal of attention. Beneficial social impacts (BSIs)-perceived benefits experienced by a participant and resulting from their trial participation-are a critical component of participants' experiences, yet they have received little attention.

SETTING

All HIV Vaccine Trials Network trial participants for whom social impact data were available-8347 participants in 13 countries who enrolled in 48 phase 1, 2a, and 2b trials.

METHODS

A cross-protocol analysis to assess self-reported BSIs and NSIs related to participating in a preventive HIV vaccine trial. Data were obtained from 48 completed HIV Vaccine Trials Network vaccine trials from December 2000 to September 2017.

RESULTS

Overall, 6572 participants (81%) reported at least one BSI, and 686 participants (8%) reported 819 NSI events. Altruism/feeling good helping others was the BSI most often endorsed by study participants (43%), followed by receiving risk-reduction counseling (30%). Most NSI events (81%) were reported by US/Swiss participants, and most (79%) trial-related NSIs were negative reactions from friends, family, and partners. Of the NSIs reported, 7% were considered to have a major impact on the participant's quality of life.

CONCLUSION

Our results underscore the relatively common experiences of BSIs among preventive HIV vaccine trial participants and mirror the results of other studies that find infrequent reports of NSIs.

HIV Vaccine Preparedness among Men Who Have Sex with Men in Taiwan: Sociocultural and Behavioral Factors

In Taiwan, men who have sex with men (MSM) are at disproportionate risk of HIV infection. We examined awareness and acceptability of future HIV vaccines. From July to August 2014, we conducted a cross-sectional survey with MSM recruited through community-based organizations (CBOs) in 2 cities. Among 200 participants (mean age, 27.6 years), half reported multiple partners and one-third condomless anal sex (past 3 months); 12% were HIV-positive. Traditional Chinese medicine (TCM) use was reported by 42.7%. Over two-thirds (69.0%) were aware of HIV vaccine research, but less than half (43.8%) would accept an HIV vaccine if available. In multivariable analysis, higher educational attainment, >5 sex partners, and TCM use were positively associated with HIV vaccine awareness. Culturally informed HIV vaccine preparedness in Taiwan may be supported by a complementary approach to TCM and HIV prevention technologies, tailoring information for MSM with lower education and targeting those at high risk through gay-identified CBOs.

Perception of potential harm and benefits of HIV vaccine trial participation: A qualitative study from urban Tanzania

BACKGROUND

The development of an effective preventive HIV vaccine is the best-known option to halt incident HIV infections. Participants in HIV vaccine trials may possess expectations shaped by existing socio-cultural contexts that are important to understand to allow for improved trial design. Here, we describe post-phase I/II HIV vaccine trial perceptions within participating communities in Dar es Salaam, Tanzania.

MATERIALS AND METHODS

This descriptive qualitative study was conducted in May 2016. We conducted eight focus group discussions, each consisting of 5 to 12 participants. Four groups comprised of the past phase I/II HIV vaccine trial participants and four groups involved those who did not participate. We used a thematic analysis approach.

RESULTS

Ongoing concerns existed among non-vaccine trial participants who believed that those who participated in HIV vaccine trials were infected with HIV. Limited post-HIV vaccine trial result dissemination, the pre-existing negative beliefs about vaccines, and experiences from other previous medical experiments fueled these concerns. The participants anticipated that broader dissemination of facts regarding HIV vaccine trials using media, former volunteers, and flyers would reduce the reported concerns. In contrast, some participants embraced the benefits gained through participating in HIV vaccine trials. HIV vaccine trial participants appreciated trial interventions, such as health status check-ups, knowledge acquisition, and facilitation of access to medical services. They envisioned mutual benefits in the form of community protection and capacity building among the local scientists.

CONCLUSIONS

The future conduct of HIV vaccine trials in Tanzania requires wider community dissemination of information and post-trial feedback to alleviate concerns among the participating communities. Interventions such as medical services may represent essential incentives to the HIV vaccine trial volunteers. In future HIV vaccine trials, it is crucial to boost individual and perceived mutual benefits.

'Why would you promote something that is less percent safer than a condom?': Perspectives on partially effective HIV prevention technologies among key populations in South Africa

New biomedical prevention technologies (NPTs) for HIV, including oral Pre-Exposure Prophylaxis, and vaginal and rectal microbicides and HIV vaccines in development, may contribute substantially to controlling the HIV epidemic. However, their effectiveness is contingent on product acceptability and adherence. We explored perceptions and understanding of partially effective NPTs with key populations in South African townships. From October 2013 to February 2014, we conducted six focus groups and 18 individual interviews with Xhosa-speaking adolescents (n = 14), adult men who have sex with men (MSM) (n = 15), and adult heterosexual men (n = 9) and women (n = 10), and eight key informant (KI) interviews with healthcare workers. Interviews/focus groups were transcribed and reviewed using a thematic approach and framework analysis. Overall, participants and KIs indicated scepticism about NPTs that were not 100% efficacious. Some participants equated not being 100% effective with not being completely safe, and thus not appropriate for dissemination. KIs expressed concerns that promoting partially effective NPTs would encourage substitution of a more effective with a less effective method or encourage risk compensation. Educational and social marketing interventions that address the benefits and appropriate use of partially effective NPTs, including education and support tailored for frontline service providers, are needed to prepare for successful NPT implementation in South Africa.

Human papillomavirus vaccine acceptability and decision-making among adolescent boys and parents: A meta-ethnography of qualitative studies

OBJECTIVE

Genital warts and human papillomavirus (HPV)-associated cancers in men can be substantially reduced through HPV vaccination; yet, globally, HPV vaccine uptake among boys remains low. This meta-ethnography synthesizes qualitative studies to understand, in-depth, HPV vaccine acceptability and decision-making among adolescent boys and/or their parents.

METHODS

A systematic search identified qualitative studies examining HPV vaccines from the perspectives of boys and/or boys' parents. The Consolidated Criteria for Reporting Qualitative Research (COREQ) 32-item checklist was used to assess quality of reporting. Using meta-ethnographic techniques, we conducted a structured and iterative process of data analysis, coded original studies, and then developed descriptive and analytic themes to synthesize the findings.

RESULTS

Review of 15 eligible studies (n = 3362 parents, n = 39 boys) revealed multilevel factors that influence HPV vaccine acceptability and decision-making among adolescent boys and their parents: (1) individual, e.g., low HPV vaccine knowledge/awareness, (2) interpersonal, e.g., key relationships between parents, sons, and healthcare providers (HCP), (3) community/societal, e.g., parental duty to protect, and (4) systemic, e.g., HPV vaccine messaging. Parents generally accepted adolescent boys' sexuality and the need for vaccination, motivated by wanting to protect their sons from HPV and HPV-associated cancers, and valued HCP-initiated discussion and recommendation. Acceptability was mitigated by low awareness/knowledge of HPV vaccines and low perceived benefits for boys, lack of HCP-initiated discussion, out-of-pocket costs, multiple doses, stigma, and mixed messages about HPV.

CONCLUSIONS

Multilevel factors influence HPV vaccine acceptability and decision-making among parents and their adolescent sons. Providing clear and unambiguous messages about HPV vaccines-for whom (boys and girls), for what (genital warts and cancers in men), and when (before sexual debut)-through increased HCP-initiated discussion and targeted public health campaigns may support HPV vaccine uptake among boys. Future research should consistently disaggregate findings by sex of child and parent, and explore effective messaging tailored for boys and parents.

Contexts of vulnerability and the acceptability of new biomedical HIV prevention technologies among key populations in South Africa: A qualitative study

BACKGROUND

New biomedical prevention technologies (NPTs) may contribute to substantially reducing incident HIV infections globally. We explored acceptability and preferences for NPTs among key and other vulnerable populations in two South African townships.

METHODS

We conducted six focus groups and 12 in-depth interviews with adolescents, and adult heterosexual men, women, and men who have sex with men (MSM) (n = 48), and eight in-depth interviews with key informant healthcare workers. The interview guide described pre-exposure prophylaxis (PrEP), vaginal rings, rectal microbicides and HIV vaccines, and explored acceptability and product preferences. Focus groups and in-depth interviews (45-80 minutes) were conducted in Xhosa, audiotaped, and transcribed and translated into English. Data were coded and reviewed using framework analysis with NVivo software.

RESULTS

Overall, initial enthusiasm and willingness to use NPTs evolved into concerns about how particular NPTs might affect or require alterations in one's everyday lifestyle and practices. Different product preferences and motivations emerged by population based on similarity to existing practices and contexts of vulnerability. Adult women and female adolescents preferred a vaginal ring and HIV vaccine, motivated by longer duration of protection to mitigate feared repercussions from male partners, including threats to their marriage and safety, and a context of ubiquitous rape. Male adolescents preferred an HIV vaccine, seen as protection in serodiscordant relationships and convenient in obviating the HIV stigma and cost involved in buying condoms. Adult men preferred PrEP, given familiarity with oral medications and mistrust of injections, seen as enabling serodiscordant couples to have a child. MSM preferred a rectal microbicide given familiarity with gel-based lubricants, with concerns about duration of protection in the context of unplanned consensual sex and rape.

CONCLUSIONS

Biomedical interventions to prevent HIV transmission, rather than obviating social-structural factors that produce vulnerability, may be limited by these same factors. Implementation of NPTs should engage local communities to understand real-world constraints and strategise to deliver effective, multi-level combination prevention.

If We Build It, Will They Come? Perceptions of HIV Cure-Related Research by People Living with HIV in Four U.S. Cities: A Qualitative Focus Group Study

Global interest and investment in the search for an HIV cure has increased. Research has focused on what experts refer to as a sterilizing or eradicating cure, where HIV is eliminated from the body, and on what is often called a functional cure, where HIV remains, kept durably suppressed in the absence of antiretroviral treatment and therapy (ART). Many believe that a functional cure is likely to be found first. HIV cure studies will require active participation by people living with HIV (PLWHIV). Their desires and perceptions will be important to effectively recruit study participants and for the uptake of any future strategy that demonstrates safety and efficacy. The perspectives of PLWHIV are essential to advancing HIV cure research, and they should be taken into consideration as biomedical research advances. We conducted 10 focus groups in four U.S. cities, eliciting perspectives of PLWHIV on HIV cure and cure research. Most participants conceived of a cure as eradicating, and felt favorably toward it. In addition to the physical benefits of a potential cure, participants valued the possible de-stigmatization related to no longer living with HIV, liberation from concerns about transmitting HIV, and freedom from the burden of daily medication. Many participants did not regard a functional cure as an improvement over controlling HIV through ART, were distrustful about viral rebound potential, and noted concerns about medical complications and accompanying psychological distress. Some felt that the risks of HIV cure research were not worth taking. Many were skeptical about science's ability to eliminate HIV from the body.

Acceptability and Preferences for Hypothetical Rectal Microbicides among a Community Sample of Young Men Who Have Sex with Men and Transgender Women in Thailand: A Discrete Choice Experiment

Rectal microbicides (RMs) may offer substantial benefits in expanding HIV prevention options for key populations. From April to August 2013, we conducted Tablet-Assisted Survey Interviewing, including a discrete choice experiment, with participants recruited from gay entertainment venues and community-based organizations in Chiang Mai and Pattaya, Thailand. Among 408 participants, 74.5 % were young men who have sex with men, 25.5 % transgender women, with mean age = 24.3 years. One-third (35.5 %) had ≤9th grade education; 63.4 % engaged in sex work. Overall, 83.4 % reported they would definitely use a RM, with more than 2-fold higher odds of choice of a RM with 99 versus 50 % efficacy, and significantly higher odds of choosing gel versus suppository, intermittent versus daily dosing, and prescription versus over-the-counter. Sex workers were significantly more likely to use a RM immediately upon availability, with greater tolerance for moderate efficacy and daily dosing. Engaging key populations in assessing RM preferences may support biomedical research and evidence-informed interventions to optimize the effectiveness of RMs in HIV prevention.

Effect of race/ethnicity on participation in HIV vaccine trials and comparison to other trials of biomedical prevention

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.

Development of an HIV vaccine attitudes scale to predict HIV vaccine acceptability among vulnerable populations: L.A. VOICES

BACKGROUND

Decade-long delays in successful implementation of Hepatitis B vaccines and ongoing obstacles in HPV vaccine roll-out suggest the importance of an implementation science approach to prepare for the effective translation of future HIV vaccines from clinical trials into routine practice. The objective of this study was to test HIV vaccine attitude items to develop reliable scales and to examine their association with HIV vaccine acceptability.

METHODS

HIV vaccine attitude items were assessed as part of the L.A. VOICES survey, a large-scale study conducted among underserved residents of Los Angeles, to identify factors that may influence HIV vaccine acceptability. Participants (n=1225) were randomly selected from public STD clinics, needle exchange sites and Latino community clinics using three-stage, venue-based time space sampling.

RESULTS

Exploratory factor analysis across 20 items revealed four distinct factors - mistrust, HIV vaccine social concerns, risk compensation, and altruistic vaccination - with acceptable reliability coefficients for each subscale (Cronbach's α range 0.61-0.84). We found no significant differences in reliability by gender or by vaccine acceptability. Risk compensation (odds ratio (OR)=1.49; 95% CI=[1.18, 1.89]; p=0.001) and altruistic vaccination (OR=1.40; 95% CI=[1.14, 1.71]; p=0.001) were significantly and positively associated with HIV vaccine acceptability.

CONCLUSIONS

We identified four HIV vaccine attitude scales with sound internal reliability parameters. In the aftermath of the first candidate vaccine to demonstrate efficacy against HIV infection, these scales may be helpful in bridging expectable research-to-practice gaps in future HIV vaccine dissemination among populations at risk. As HIV vaccine trials progress in the United States and globally, these measures also may be useful as a tool to assess and facilitate effective responses to community concerns about HIV vaccine trials and to target interventions to support recruitment and mitigate risk compensation.

HIV vaccine acceptability among high-risk drug users in Appalachia: a cross-sectional study

Background

A vaccine could substantially impact the HIV epidemic, but inadequate uptake is a serious concern. Unfortunately, people who use drugs, particularly those residing in rural communities, have been underrepresented in previous research on HIV vaccine acceptability. This study examined HIV vaccine acceptability among high-risk drug users in a rural community in the United States.

Methods

Interviewer-administered questionnaires included questions about risk behavior and attitudes toward HIV vaccination from 433 HIV-negative drug users (76% with history of injection) enrolled in a cohort study in Central Appalachia. HIV vaccine acceptability was measured on a 4-point Likert scale. Generalized linear mixed models were used to determine correlates to self-report of being “very likely” to receive a 90% effective HIV vaccine (i.e. “maximum vaccine acceptability”, or MVA). Adjusted odds ratios (AORs) and corresponding 95% confidence intervals (CIs) are reported.

Results

Most (91%) reported that they would accept a preventive HIV vaccine, but concerns about cost, dosing, transportation constraints, vaccine-induced seropositivity, and confidentiality were expressed. Cash incentives, oral-administration, and peer/partner encouragement were anticipated facilitators of uptake. In multivariate analysis, men were significantly less likely to report MVA (AOR: 0.33, CI: 0.21 – 0.52). MVA was more common among participants who believed that they were susceptible to HIV (AOR: 2.31, CI: 1.28 – 4.07), that an HIV vaccine would benefit them (AOR: 2.80, CI: 1.70 – 4.64), and who had positive experiential attitudes toward HIV vaccination (AOR: 1.85, CI: 1.08 – 3.17). MVA was also more common among participants who believed that others would encourage them to get vaccinated and anticipated that their behavior would be influenced by others' encouragement (AOR: 1.81, 95% 1.09 – 3.01).

Conclusions

To our knowledge, this study was among the first to explore and provide evidence for feasibility of HIV vaccination in a rural, high-risk population in the United States. This study provides preliminary evidence that gender-specific targeting in vaccine promotion may be necessary to promoting vaccine uptake in this setting, particularly among men. The data also underscore the importance of addressing perceived risks and benefits, social norms, and logistical constraints in efforts to achieve widespread vaccine coverage in this high-risk population.

"Sisters, Mothers, Daughters and Aunties": HIV vaccine acceptability among African, Caribbean and other Black women in Toronto

OBJECTIVES

Black women in Canada are at disproportionately high risk for HIV. We assessed HIV vaccine acceptability and correlates of acceptability among Black women from African and Caribbean communities in Toronto.

METHODS

"Sisters, Daughters, Mothers, and Aunties" was a community-based research project. Black women of African and Caribbean descent were recruited using venue-based sampling across diverse community organizations in Toronto. We used a structured questionnaire to collect data on socio-demographic characteristics and acceptability of 8 future HIV vaccines, each defined by a set of 7 dichotomous attributes. Conjoint analysis was used to quantify the relative impact of vaccine attributes on acceptability, with multiple regression to adjust for socio-demographic characteristics associated with overall acceptability.

RESULTS

Mean vaccine acceptability was 58.8 (SD=17.2) on the 100-point scale. Efficacy had the greatest impact on acceptability, followed by side effects, cost, duration of protection, and number of doses. Acceptability of a high (99%) efficacy vaccine (70.1/100) was significantly greater than for a 50% efficacy vaccine (47.6/100). Vaccine acceptability was significantly higher among women of Caribbean versus African descent, ever married versus single women, and women with full-time versus part-time employment.

CONCLUSIONS

Black women in Toronto indicated a modest level of acceptability for future HIV vaccines. Educational interventions that address the benefits of partially efficacious vaccines and clearly explain potential side effects, as well as vaccine cost subsidies may promote HIV vaccine uptake. Differences in acceptability within Black communities suggest that tailored multi-level interventions may mitigate barriers to uptake.

The marginal willingness-to-pay for attributes of a hypothetical HIV vaccine

This paper estimates the marginal willingness-to-pay for attributes of a hypothetical HIV vaccine using discrete choice modeling. We use primary data from 326 respondents from Bangkok and Chiang Mai, Thailand, in 2008-2009, selected using purposive, venue-based sampling across two strata. Participants completed a structured questionnaire and full rank discrete choice modeling task administered using computer-assisted personal interviewing. The choice experiment was used to rank eight hypothetical HIV vaccine scenarios, with each scenario comprising seven attributes (including cost) each of which had two levels. The data were analyzed in two alternative specifications: (1) best-worst; and (2) full-rank, using logit likelihood functions estimated with custom routines in Gauss matrix programming language. In the full-rank specification, all vaccine attributes are significant predictors of probability of vaccine choice. The biomedical attributes of the hypothetical HIV vaccine (efficacy, absence of VISP, absence of side effects, and duration of effect) are the most important attributes for HIV vaccine choice. On average respondents are more than twice as likely to accept a vaccine with 99% efficacy, than a vaccine with 50% efficacy. This translates to a willingness to pay US$383 more for a high efficacy vaccine compared with the low efficacy vaccine. Knowledge of the relative importance of determinants of HIV vaccine acceptability is important to ensure the success of future vaccination programs. Future acceptability studies of hypothetical HIV vaccines should use more finely grained biomedical attributes, and could also improve the external validity of results by including more levels of the cost attribute.

Anticipated changes in sexual risk behaviour following vaccination with a low-efficacy HIV vaccine: survey results from a South African township

We assessed the potential for anticipated changes in sexual risk-taking behaviour following hypothetical administration of a low-efficacy preventive HIV vaccine. We developed a survey and collected self-reported data from 158 HIV-negative volunteers in a cohort undergoing prescreening for Phase I/II HIV vaccine trials in Soweto. Overall, 22% reported they might use condoms less frequently; 9% reported that they might increase their frequency of sex with casual/anonymous partners; and 55% reported their sexual partners might want to use condoms less frequently knowing they were vaccinated. Multivariate analyses revealed that anticipated decrease in condom use was predicted by poor comprehension and by young age. Individuals may increase their risk-taking behaviour knowing that a vaccine would provide only incomplete protection against HIV transmission. In HIV vaccine trials and future vaccination programmes, education and risk-reduction counselling will be needed for vaccinated individuals and their partners, and mass media education campaigns may be necessary.

Enrollment in YFV Vaccine Trial: An Evaluation of Recruitment Outcomes Associated with a Randomized Controlled Double-Blind Trial of a Live Attenuated Yellow Fever Vaccine

This investigation evaluated several factors associated with diverse participant enrollment of a clinical trial assessing safety, immunogenicity, and comparative viremia associated with administration of 17-D live, attenuated yellow fever vaccine given alone or in combination with human immune globulin. We obtained baseline participant information (e.g., sociodemographic, medical) and followed recruitment outcomes from 2005 to 2007. Of 355 potential Yellow Fever vaccine study participants, 231 cases were analyzed. Strong interest in study participation was observed among racial and ethnically diverse persons with 36.34% eligible following initial study screening, resulting in 18.75% enrollment. The percentage of white participants increased from 63.66% (prescreened sample) to 81.25% (enrollment group). The regression model was significant with white race as a predictor of enrollment (OR=2.744, 95% CI=1.415-5.320, p=0.003).In addition, persons were more likely to enroll via direct outreach and referral mechanisms compared to mass advertising (OR=2.433, 95% CI=1.102-5.369). The findings indicate that racially diverse populations can be recruited to vaccine clinical trials, yet actual enrollment may not reflect that diversity.

Use of conjoint analysis to assess HIV vaccine acceptability: feasibility of an innovation in the assessment of consumer health-care preferences

Engaging consumers in prospectively shaping strategies for dissemination of health-care innovations may help to ensure acceptability. We examined the feasibility of using conjoint analysis to assess future HIV vaccine acceptability among three diverse communities: a multiethnic sample in Los Angeles, CA, USA (n = 143); a Thai resident sample in Los Angeles (three groups; n = 27) and an Aboriginal peoples sample in Toronto (n = 13). Efficacy had the greatest impact on acceptability for all three groups, followed by cross-clade protection, side-effects and duration of protection in the Los Angeles sample; side-effects and duration of protection in the Thai-Los Angeles sample; and number of doses and duration of protection in the Aboriginal peoples-Toronto sample. Conjoint analysis provided insights into universal and population-specific preferences among diverse end users of future HIV vaccines, with implications for evidence-informed targeting of dissemination efforts to optimize vaccine uptake.

The Community Liaison Program: a health education pilot program to increase minority awareness of HIV and acceptance of HIV vaccine trials

This paper describes a 16-month health education pilot program based on diffusion of innovation and social network theories. The program was implemented by volunteer community liaisons for the purposes of increasing awareness of and support for HIV vaccine research in minority populations. This theoretically driven pilot program allowed the liaisons to integrate delivery of the HIV vaccine research messages created for the program into their existing activities and routines. Through training in participatory engagement, volunteers were able to tailor and adapt an HIV prevention message for their communities. Process evaluation data showed that the acceptance of participatory engagement and HIV vaccine message dissemination far exceeded expectations. The anticipated number of community members to receive the message was estimated at 500 with 10 volunteer liaisons or 50 per person. However, the actual number of people reached was 644, with only 7 volunteer liaisons, or an average of 92 persons per liaison, almost double the original number. Further research is recommended to analyze the specific behavioral changes that can come from the use of social networks in HIV vaccine research awareness within minority populations.

Risk, individual differences, and environment: an Agent-Based Modeling approach to sexual risk-taking

Risky sexual behaviors, including the decision to have unprotected sex, result from interactions between individuals and their environment. The current study explored the use of Agent-Based Modeling (ABM)-a methodological approach in which computer-generated artificial societies simulate human sexual networks-to assess the influence of heterogeneity of sexual motivation on the risk of contracting HIV. The models successfully simulated some characteristics of human sexual systems, such as the relationship between individual differences in sexual motivation (sexual excitation and inhibition) and sexual risk, but failed to reproduce the scale-free distribution of number of partners observed in the real world. ABM has the potential to inform intervention strategies that target the interaction between an individual and his or her social environment.

A social vaccine? Social and structural contexts of HIV vaccine acceptability among most-at-risk populations in Thailand

A safe and efficacious preventive HIV vaccine would be a tremendous asset for low- and middle-income country (LMIC) settings, which bear the greatest global impact of AIDS. Nevertheless, substantial gaps between clinical trial efficacy and real-world effectiveness of already licensed vaccines demonstrate that availability does not guarantee uptake. In order to advance an implementation science of HIV vaccines centred on LMIC settings, we explored sociocultural and structural contexts of HIV vaccine acceptability among most-at-risk populations in Thailand, the site of the largest HIV vaccine trial ever conducted. Cross-cutting challenges for HIV vaccine uptake - social stigma, discrimination in healthcare settings and out-of-pocket vaccine cost - emerged in addition to population-specific barriers and opportunities. A 'social vaccine' describes broad sociocultural and structural interventions - culturally relevant vaccine promotion galvanised by communitarian norms, mitigating anti-gay, anti-injecting drug user and HIV-related stigma, combating discrimination in healthcare, decriminalising adult sex work and injecting drug use and providing vaccine cost subsidies - that create an enabling environment for HIV vaccine uptake among most-at-risk populations. By approaching culturally relevant social and structural interventions as integral mechanisms to the success of new HIV prevention technologies, biomedical advances may be leveraged in renewed opportunities to promote and optimise combination prevention.

Assessing the interest to participate in a dengue vaccine efficacy trial among residents of Puerto Rico

Dengue, endemic in Puerto Rico, is a major public health problem. Vaccines are thought the best means to prevent dengue because vector control alone has been largely ineffective. We implemented qualitative studies in 2006 and 2010 to determine the acceptability of conducting placebo-controlled dengue vaccine efficacy trials in Puerto Rican children. Key informant interviews and focus groups with parents and children were conducted in municipalities with high dengue incidence. We used structured open-ended questions to determine motivators and attitudes regarding vaccine trial participation. Knowledge about dengue risk and prevention, and knowledge, attitudes, and beliefs regarding vaccines and vaccine trials were assessed. Using grounded theory, we conducted content analysis and established categories and sub-categories of participant responses. All participants were knowledgeable about dengue prevention and perceived children as most affected age groups. Participants were aware of vaccines benefits and they thought a vaccine could prevent dengue. However, most would not allow their children to participate in a placebo-controlled vaccine trial. Barriers included lack of trust in new vaccines and vaccine trial procedures; fear of developing dengue or side effects from the vaccine and lack of information about candidate dengue vaccines. Participants thought information, including results of previous trials might overcome barriers to participation. Motivators for participation were altruism, protection from dengue, free medical attention, and compensation for transportation and participation. Parents would consider children participation if accurate vaccine trial information is provided.

Condom migration resulting from circumcision, microbicides and vaccines: brief review and methodological considerations

OBJECTIVE

To provide an updated review of condom migration as a means of highlighting methodological issues for future studies of this behavioural issue.

METHODS

Electronic searches of PubMed, MEDLINE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were carried out in October 2010 and updated in January 2011 for English-language articles published from 1994 onward.

RESULTS

Evidence addressing condom migration from microbicides and vaccines is vastly underdeveloped, simply because these products are still experimental. In contrast, the more advanced evidence regarding male circumcision is hopeful because it suggests that migration may not be an overwhelming issue. Nonetheless, the entire body of empirical evidence on this question could be substantially expanded and improved.

CONCLUSION

Until stronger evidence suggests that condom migration is unlikely, it is important to be mindful of the potential for condom migration to occur in response to biomedical interventions (circumcision, microbicides and vaccines).

"Once I begin to participate, people will run away from me": understanding stigma as a barrier to HIV vaccine research participation in Kenya

PURPOSE

Participation of volunteers in clinical research is essential to the development of effective HIV prevention methods, including an HIV vaccine. This study expands current knowledge of stigma and discrimination related to participation in HIV vaccine research in sub-Saharan Africa by exploring the perception of stigma and discrimination as a barrier to participation in HIV vaccine research in Kenya.

METHODS

Eighteen focus groups with a total of 133 participants and 82 individual interviews were conducted with a range of respondents at two centers in Nairobi, Kenya: a preventive AIDS vaccine trial center; and a preparatory clinical and epidemiological study center. Respondents included peer leaders, community advisory board members, former and current volunteers in clinical research, study staff, community leaders and community members. Data were analyzed using an iterative coding process.

RESULTS

Four prominent stigma-related barriers to participation emerged among all respondent groups, across both centers: (1) volunteers are often assumed by family and community members to be HIV positive because of their participation in vaccine research; (2) HIV-related stigma is perceived as pervasive and damaging in the communities where volunteers live, thus they fear consequent stigma if people believe them to be HIV positive; (3) potential volunteers fear being tested for HIV, a prerequisite for participation, because of possible disclosure of HIV status in communities with high perceived HIV-related stigma; and (4) volunteers must carefully manage information about their participation because of misperceptions and assumptions about vaccine research volunteers.

CONCLUSIONS

HIV-related stigma and discrimination influence people's decisions to join HIV-vaccine related research. Findings underscore a need for integration of stigma-reduction programming into education and outreach activities for volunteers, and the communities in which they live. This is particularly critical for trials recruiting individuals with higher HIV risk, who are often already highly stigmatized.

HIV vaccine acceptability and culturally appropriate dissemination among sexually diverse Aboriginal peoples in Canada

This study explored HIV vaccine acceptability and strategies for culturally appropriate dissemination among sexually diverse Aboriginal peoples in Canada, among those at highest HIV risk. We conducted four focus groups (n=23) with Aboriginal male (1) and female (1) service users, peer educators (1) and service providers (1) in Ontario, Canada. Transcripts were analysed with narrative thematic techniques from grounded theory, using NVivo. Participants' mean age was 37 years; about half (52%) were female, half (48%) Two-spirit or lesbian, gay or bisexual (LGB)-identified, 48% had a high-school education or less and 57% were unemployed. Vaccine uptake was motivated by community survival; however, negative HIV vaccine perceptions, historically based mistrust of government and healthcare institutions, perceived conflict between western and traditional medicine, sexual prejudice and AIDS stigma within and outside of Aboriginal communities, and vaccine cost may present formidable obstacles to HIV vaccine acceptability. Culturally appropriate processes of engagement emerged on individual levels (i.e., respect for self-determination, explanations in Native languages, use of modelling and traditional healing concepts) and community levels (i.e., leadership by Aboriginal HIV advocates and political representatives, identification of gatekeepers, and procuring Elders' endorsements). Building on cultural strengths and acknowledging the history and context of mistrust and social exclusion are fundamental to effective HIV vaccine dissemination.

Exploring decision-making of HIV-infected Hispanics and African Americans participating in clinical trials

Underrepresentation of HIV-infected Hispanics and African Americans in clinical trials seriously limits our understanding of the benefits and risks of treatment in these populations. This qualitative study examined factors that racial/ethnic minority patients consider when making decisions regarding research participation. A total of 35 HIV-infected Hispanic and African American patients enrolled in clinical research protocols at the National Institutes of Health were recruited to participate in focus groups and in-depth interviews. The sample included mostly male participants (n = 22), had a mean age of 45, had nearly equal representation of race/ethnicity, and were diagnosed 2 to 22 years earlier. Baseline questionnaires included demographics and measures of social support and acculturation. Interviewers had similar racial/ethnic, cultural, and linguistic backgrounds as the participants. Four major themes related to the decisions of participants to enroll in clinical trials emerged, which are as follows: enhancers, barriers, beliefs, and psychosocial context. Results may help researchers develop strategies to facilitate inclusion of HIV-infected Hispanics and African Americans into clinical trials.

HIV vaccine acceptability: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review of the literature to examine HIV vaccine acceptability and factors impacting acceptability of future HIV vaccines.

DESIGN

Systematic review and meta-analysis of peer-reviewed articles that assessed HIV vaccine acceptability.

METHODS

We used a comprehensive search strategy across multiple electronic databases to locate original quantitative or qualitative studies that examined rates or correlates of HIV vaccine acceptability. We conducted meta-analysis on studies reporting correlates or predictors of HIV vaccine acceptability.

RESULTS

Twenty studies (n=7576) reported HIV vaccine acceptability ranging from 37.2 to 94.0 on a 100-point scale; weighted mean acceptability =65.6 (SD=21.1). Eleven studies compared HIV vaccine acceptability at high (80-95%) efficacy (mean =73.8; SD=9.2) versus moderate (50%) efficacy (mean =40.4; SD=20.2). Among 13 studies (n=5023) included in meta-analysis, efficacy and non 'risk group' membership had medium effect sizes, and pragmatic obstacles, cost, perceived susceptibility to HIV infection, side effects/safety concerns, fear of vaccines, perceived vaccine benefits, duration of protection, and ethnicity had small effect sizes on HIV vaccine acceptability.

CONCLUSION

Public health strategies to promote the benefits of partial efficacy HIV vaccines and accurate HIV risk perceptions, and to dispel vaccine fears, along with structural interventions to subsidize vaccine costs and facilitate access, may increase future HIV vaccine uptake and, in turn, the effectiveness of HIV vaccines in controlling the epidemic.

Community engagement and investment in biomedical HIV prevention research for youth: rationale, challenges, and approaches

There has been a growing awareness of the importance of engaging communities in the development, testing, and eventual dissemination of biomedical strategies. Community engagement offers many benefits but comes with many challenges. This article will discuss these benefits and challenges and describe two examples of community engagement, Connect to Protect in the United States, and the South African Studies on HIV in Adolescents Project in South Africa, that represent investment in community engagement as preparation for biomedical HIV prevention clinical trials for youth.

Preventive HIV vaccine acceptability and behavioral risk compensation among high-risk men who have sex with men and transgenders in Thailand

Thailand, with the highest number of volunteers to have participated in preventive HIV-1 vaccine trials globally, may be an early adopter of HIV vaccines. We conducted a mixed methods investigation, including 30 in-depth interviews and a venue-based survey. We used a structured questionnaire including conjoint analysis and a fractional factorial experimental design to assess preventive HIV vaccine acceptability and risk compensation among 255 high-risk men who have sex with men (MSM) and transgenders (mean age=26.6 years). HIV vaccine acceptability ranged from 31.6 to 73.8 on a 100-point scale; mean=58.3 (SD=17.1). Vaccine-induced seropositivity (VISP) had the greatest impact on acceptability, followed by efficacy, side effects, duration of protection, out-of-pocket cost and social saturation. Over one-third (34.6%) reported intentions to increase post-vaccination risk behaviors in response to a highly efficacious HIV vaccine. Social and structural interventions to promote HIV vaccine uptake as a prosocial behavior, provide accessible assays to detect VISP, and subsidize vaccine costs, and support for uptake of partially efficacious vaccines in the context of combination prevention, will facilitate HIV vaccine dissemination in Thailand.

Preventive HIV vaccine acceptability and behavioral risk compensation among a random sample of high-risk adults in Los Angeles (LA VOICES)

OBJECTIVE

To assess HIV vaccine acceptability among high-risk adults in Los Angeles.

STUDY SETTING

Sexually transmitted disease clinics, needle/syringe exchange programs, Latino community health/HIV prevention programs.

STUDY DESIGN

Cross-sectional survey using conjoint analysis. Participants were randomly selected using three-stage probability sampling.

DATA COLLECTION

Sixty-minute structured interviews. Participants rated acceptability of eight hypothetical vaccines, each with seven dichotomous attributes, and reported post-vaccination risk behavior intentions.

PRINCIPAL FINDINGS

Participants (n=1164; 55.7 percent male, 82.4 percent ethnic minority, mean age=37.4 years) rated HIV vaccine acceptability from 28.4 to 88.6; mean=54.5 (SD=18.8; 100-point scale). Efficacy had the greatest impact on acceptability, followed by side effects and out-of-pocket cost. Ten percent would decrease condom use after vaccination.

CONCLUSIONS

Findings support development of social marketing interventions to increase acceptability of "partial efficacy" vaccines, behavioral interventions to mitigate risk compensation, and targeted cost subsidies.

The past, present, and future of HIV prevention: integrating behavioral, biomedical, and structural intervention strategies for the next generation of HIV prevention

In the past 25 years, the field of HIV prevention research has been transformed repeatedly. Today, effective HIV prevention requires a combination of behavioral, biomedical, and structural intervention strategies. Risk of transmitting or acquiring HIV is reduced by consistent male- and female-condom use, reductions in concurrent and/or sequential sexual and needle-sharing partners, male circumcision, and treatment with antiretroviral medications. At least 144 behavioral prevention programs have been found effective in reducing HIV transmission acts; however, scale up of these programs has not occurred outside of the United States. A series of recent failures of HIV-prevention efficacy trials for biomedical innovations such as HIV vaccines, treating herpes simplex 2 and other sexually transmitted infections, and diaphragm and microbicide barriers highlights the need for behavioral strategies to accompany biomedical strategies. This challenges prevention researchers to reconceptualize how cost-effective, useful, realistic, and sustainable prevention programs will be designed, delivered, tested, and diffused. The next generation of HIV prevention science must draw from the successes of existing evidence-based interventions and the expertise of the market sector to integrate preventive innovations and behaviors into everyday routines.

Engaging members of African American and Latino communities in preventive HIV vaccine trials

BACKGROUND

African Americans (AAs) and Latinos in United States bear a disproportionate burden of HIV infection, yet remain underrepresented in HIV vaccine trials. The success in engaging and enrolling AAs and Latinos in phase 1 and phase 2 vaccine trials at 2 research sites in New York City is described.

METHODS

A retrospective analysis of 1683 HIV-uninfected individuals who completed > or = 1 stage of the screening process from 2002 to 2006. Data on sociodemographic, behavioral characteristics, medical eligibility, and enrollment in National Institutes of Health-sponsored vaccine trials were collected.

RESULTS

7.5% of screening participants completed enrollment; 33% were AAs, 24% Latinos. The proportion of enrollees did not differ significantly by race/ethnicity. Low-risk vs. high-risk AAs (49% vs. 23%, P = 0.006) and high-risk vs. low-risk Latinos (31% vs. 13%, P = 0.006) were more likely to enroll. Among them, loss to follow-up was the most common reason for not completing screening. In multivariate analysis, older participants, high-risk men, and high-risk women were more likely to complete enrollment.

CONCLUSIONS

Once potential minority participants are identified and engaged in the screening process, it is possible to enroll them at rates comparable to white participants. Experience at these sites suggests that the challenge in achieving high rates of minority participation is in increasing the initial pool of candidates prescreening for HIV vaccine studies.

Understanding differences in enrollment outcomes among high-risk populations recruited to a phase IIb HIV vaccine trial

BACKGROUND

The Step Study, a Phase IIb HIV vaccine proof of concept study, enrolled approximately 3000 persons in clade B regions. The Atlanta site sought to enroll a diverse population. This prospective cohort study examined key factors associated with participant enrollment.

METHODS

We obtained participant information (eg, sociodemographic, medical) and followed outcomes from 2005 to 2007. Of the 810 potential "Step Study" participants, 340 cases were analyzed.

RESULTS

The recruitment strategy generated strong interest among minorities with 37% eligible after prescreening, yet 25% of the minorities enrolled. However, the percentage of whites increased from 62% eligible (prescreened sample) to 75% enrolled. The regression model was significant with educational level being an enrollment predictor (P = 0.0023). Those with at least a bachelor's degree were more likely to enroll compared with those with a K-12 education or some college (odds ratio = 2.424, 95% confidence interval = 1.372 to 4.281, P < 0.01). White race was also a significant factor (odds ratio = 2.330; 95% confidence interval = 1.241 to 4.375, P < 0.01). No difference in enrollment was observed among recruitment approaches, Pearson chi (2) (n = 336) = 5.286, P = 0.07.

CONCLUSIONS

The results from this study indicate that women, minorities, and those with lower educational attainment were less likely to enroll in an HIV vaccine efficacy study at our site. The findings highlight an important consideration on the role of health literacy to sustain participation of eligible minorities in HIV vaccine trials.

Factors associated with willingness to participate in HIV vaccine trials among high-risk populations in South India

Abstract Successful conduct of any HIV vaccine trial (HIVVT) requires a high level of preparedness in the community. A cross-sectional study was conducted in Tamilnadu, India among 501 participants from six different risk groups to investigate their willingness to participate (WTP) in future preventive HIVVTs and to explore their knowledge and attitude toward preventive HIV vaccines. In total, 82% were willing to participate and the desire to be protected from HIV was the main reason for WTP. Perception of not being at risk was the major reason for refusal among married women. The knowledge scale showed a significant increase in scores after vaccine education. In all, 76% revealed the hope that there would be an effective vaccine in a few years and 71% hoped that the HIV vaccine would protect them from HIV infection. The main concern was the unknown efficacy of the vaccine (50%) and the effects of an HIV vaccine on participants' lives (51%). Overall, 76% agreed that sex without a condom would not be safe whether or not there was an HIV vaccine. To conclude, it is likely that high-risk volunteers will be willing to enroll in preventive HIVVTs. Addressing barriers and concerns by providing information through appropriate agencies will spell out success for preventive HIVVTs in India.

HIV vaccine acceptability among immigrant Thai residents in Los Angeles: a mixed-method approach

This study examined HIV vaccine acceptability among immigrant Thai residents in Los Angeles, California. We combined a qualitative research method (focus groups) with an innovative market research method (conjoint analysis). Focus groups explored social issues, concerns, barriers and motivators associated with HIV vaccine acceptability. Conjoint analysis was used to assess preferences among eight hypothetical HIV vaccines with varying attribute profiles and the impact of various attributes on acceptability. Five main themes were identified in the focus groups regarding acceptance and utilization of preventive HIV vaccines: (1) vaccine characteristics, such as efficacy, physical side-effects and cost, (2) fear of a vaccine, (3) vaccine acceptability and optimism, (4) social and family responses and (5) behavioral disinhibition. Conjoint analysis revealed HIV vaccine acceptability ranging from 7.4 (SD = 19.4) to 85.2 (SD = 24.3) across eight hypothetical vaccines. The vaccine with the highest acceptability had the following attributes: 99% efficacy, no side-effects, 10 years of protection, protects against one sub-type, free, one dose and given by injection. Vaccine efficacy had the greatest impact on acceptability (51.4, p=.005), followed by side-effects (11.1, p=.005) and duration of protection (8.3, p=.005). Despite some apprehensions and concerns, Thai residents perceived an HIV vaccine as making an important contribution to society and to protecting oneself and one's family from HIV infection. Nevertheless, acceptability of a partially efficacious vaccine may be low, suggesting the need for tailored social marketing interventions that might emphasize a collectivistic rather than an individualistic focus. Assessing HIV vaccine acceptability using a mixed-method approach is feasible with Thai residents and should lend itself to HIV vaccine research with other Asian Pacific Islander populations in the US.

Sexual risk behavior has decreased among men who have sex with men in Los Angeles but remains greater than that among heterosexual men and women

We examined changes and correlates of sexual risk behavior of men who have sex with men (MSM) compared with heterosexual men and women over three time periods. Data from the 1997, 1999, and 2003 Los Angeles County Health Surveys, a population-based telephone survey, were analyzed to examine the association of sociodemographic and health-related factors with sexual risk behaviors among the three groups. In each time period, MSM reported a significantly greater percentage of sexual risk (i.e., both inconsistent condom use and multiple sex partners in the past 12 months) compared with heterosexual men and women. Multivariate analyses indicated that MSM and heterosexual men reported greater sexual risk than heterosexual women. Respondents who were younger, U.S. born, reported heavy alcohol consumption, or had been tested for HIV in the past 24 months were more likely to report sexual risk behavior. The findings suggest the need for continued targeted prevention for MSM and prevention efforts for segments of the general population at elevated risk for HIV.

What can HIV vaccine trials teach us about future HIV vaccine dissemination?

This investigation explored commonalities and differences in barriers and motivators to HIV vaccine trial participation and acceptability of future U.S. Food and Drug Administration (FDA)-approved HIV vaccines in order to identify implications of clinical trials for future HIV vaccine dissemination. Fifteen focus groups were conducted with 157 predominately ethnic minority and low income participants recruited using venue-based sampling in Los Angeles. Data were analyzed using narrative thematic analysis. Barriers and motivators in common across willingness to participate (WTP) in HIV vaccine trials and future HIV vaccine acceptability (e.g., concerns about vaccine-induced infection, false-positives, side effects, efficacy, mistrust and stigma) suggest clinical trials present significant opportunities to develop and evaluate empirically based interventions to support future HIV vaccine dissemination. Barriers specific to HIV vaccine acceptability (e.g., concerns about duration of protection, cross-clade protection, cost and access) also indicate the need for formative research focused specifically on future dissemination. Protection motivation, common to WTP and acceptability, highlights the need to provide and evaluate prevention counseling and education in clinical trials, which may form the basis of evidence-informed preventive interventions to be launched in tandem with dissemination of partial efficacy HIV vaccines.

Participation in two phase II prophylactic HIV vaccine trials in the UK

There will be a continued imperative to recruit large numbers of healthy volunteers to early phase prophylactic HIV vaccine (PHV) trials. We studied mechanisms associated with participation in two related phase II PHV trials. The most cited reasons for volunteering were altruism and a personal connection to HIV. The most successful recruiting strategies targeted organisations dealing with HIV, health or social issues, or were directed to large audiences through the mass media. However, circulated emails and word of mouth were the most resource-effective approaches. Group discussions and the collection of a pool of potential volunteers were much less effective than one-to-one discussions and immediate screening after recruitment. We utilised our findings to devise key recommendations to assist PHV trial teams who are planning future studies.

A small dose of HIV? HIV vaccine mental models and risk communication

Existing knowledge and beliefs related to HIV vaccines provide an important basis for the development of risk communication messages to support future HIV vaccine dissemination. This study explored HIV vaccine mental models among adults from segments of the population disproportionately affected by HIV/AIDS. Nine focus groups were conducted with participants (N = 99; median age = 33 years; 48% female; 22% African American, 44% Latino, and 28% white) recruited from needle exchange sites, public clinics, and gay community centers in Los Angeles. Data were analyzed using narrative thematic analysis and Ethnograph qualitative software. Mental models of HIV vaccines included live virus, side effects, complete protection (100% efficacy, lifetime protection, reduced anxiety about HIV/AIDS), and "high-risk groups." HIV vaccine risk communication to counter undue fears of vaccine-induced infection and side effects and to mitigate exaggerated expectations of a "magic bullet" may be vital to the effectiveness of first-generation HIV vaccines in controlling the AIDS epidemic.

Predicting the impact of a partially effective HIV vaccine and subsequent risk behavior change on the heterosexual HIV epidemic in low- and middle-income countries: A South African example

We developed a mathematical model to simulate the impact of various partially effective preventive HIV vaccination scenarios in a population at high risk for heterosexually transmitted HIV. We considered an adult population defined by gender (male/female), disease stage (HIV-negative, HIV-positive, AIDS, and death), and vaccination status (unvaccinated/vaccinated) in Soweto, South Africa. Input data included initial HIV prevalence of 20% (women) and 12% (men), vaccination coverage of 75%, and exclusive male negotiation of condom use. We explored how changes in vaccine efficacy and postvaccination condom use would affect HIV prevalence and total HIV infections prevented over a 10-year period. In the base-case scenario, a 40% effective HIV vaccine would avert 61,000 infections and reduce future HIV prevalence from 20% to 13%. A 25% increase (or decrease) in condom use among vaccinated individuals would instead avert 75,000 (or only 46,000) infections and reduce the HIV prevalence to 12% (or only 15%). Furthermore, certain combinations of increased risk behavior and vaccines with <43% efficacy could worsen the epidemic. Even modestly effective HIV vaccines can confer enormous benefits in terms of HIV infections averted and decreased HIV prevalence. However, programs to reduce risk behavior may be important components of successful vaccination campaigns.

Factors Influencing Pediatricians' Intention to Recommend Human Papillomavirus Vaccines

OBJECTIVES

The objectives of this qualitative study were to describe the range of pediatricians' attitudes about human papillomavirus (HPV) vaccines and to explore factors influencing their intention to recommend HPV vaccines, extending the findings of previous quantitative studies.

METHODS

A diverse sample of pediatricians participated in semistructured individual interviews to assess attitudes and intentions regarding HPV immunization. Framework analysis was used for qualitative analysis.

RESULTS

The mean age of the 31 participants was 47 years, 17 (55%) were female, 9 (29%) were black, and 4 (13%) were Latino. The efficacy, safety, and potential health impact of vaccination were the primary factors driving participants' decisions about recommending HPV vaccines. Perceived benefits of HPV vaccination included prevention of HPV-related disease and the opportunity to educate adolescents. Perceived barriers included anticipated parental beliefs (eg, parental denial that their child would be at risk) and provider beliefs (eg, reluctance to discuss sexuality with preadolescents). Participants reported high intention to recommend HPV vaccines overall, but intention varied according to patient age, patient gender, and HPV vaccine type. The primary reasons underlying this variation included perceptions about the health impact of vaccination and relevance of HPV vaccines to the provider's patients. The main factors driving intention to recommend HPV vaccines included knowledge, personal and professional characteristics, office procedures, vaccine cost and reimbursement, parental factors, and specific attitudes about HPV vaccination.

CONCLUSIONS

These findings provide a framework for understanding pediatricians' decisions to recommend HPV vaccines and may be used to guide the design of interventions to maximize vaccine recommendations.

Willingness to participate in HIV vaccine trials: the impact of trial attributes

OBJECTIVES

To assess willingness to participate (WTP) in hypothetical Phase III preventive HIV vaccine trials, and the impact of trial attributes on WTP, among low socioeconomic, ethnically diverse adults from communities at elevated risk for HIV infection.

METHOD

Participants (n=123; median age=38; 69% male; 37% Latino; 14% African-American) were recruited in Los Angeles in 2003 using multi-site, venue-based sampling. WTP was assessed for eight hypothetical HIV vaccine trials that varied across seven dichotomous attributes, using a 2(7-4) fractional factorial experimental design. Individual-specific impact of vaccine trial attributes on WTP was estimated using within-individual ANOVA and then meta-analyzed across individuals.

RESULTS

Mean WTP for eight hypothetical vaccine trials ranged from 1.74 to 3.81 (1=highly unlikely, 5=highly likely). Lower WTP was associated with vaccine-induced infection risk (impact=0.88, p<0.0001), false HIV-positives (0.53, p<0.0001), no provision of free HIV medications (0.52, p<0.0001), and longer trial duration (0.27; p=0.0002).

CONCLUSION

HIV vaccine trial attributes may strongly influence WTP. Although existing candidate vaccines cannot cause HIV infection, perceptions of risk may impede WTP. Eliciting trial preferences and concerns prior to trial implementation may enable accommodation of participant preferences and support tailored interventions to address concerns and misconceptions to facilitate enrollment in safe and ethical trials among vulnerable communities.

HIV vaccine trial preparedness among Spanish-speaking Latinos in the US

Latinos are under-represented in HIV/AIDS medical research in the US. Although they are disproportionately impacted by HIV/AIDS, Latinos may be reluctant to participate in HIV vaccine trials. Three focus groups were conducted with 32 Spanish-speaking Latinos recruited from two community-based healthcare organizations in Los Angeles, California. A qualitative focus group interview guide was developed to explore concerns, motivators and intentions in regard to participation in HIV vaccine trials. Mistrust and fear of government emerged as important themes related to reluctance to participate in an HIV vaccine trial. Specific concerns regarding trial participation included: (1) fear of vaccine-induced HIV infection, (2) physical side effects, (3) stigma and (4) false-induced HIV-positive test results and their social repercussions. Motivators for enrolling in an HIV vaccine trial included: (1) incentives, (2) convenience of participating in a study, (3) sufficient and appropriate study information, (4) personal benefits and (5) altruism. Interventions to facilitate participation by Latinos in HIV vaccine trials should address mistrust and fear of government-sponsored HIV/AIDS medical research, increase access to and convenience of clinical trials, address fear of vaccine-induced infection, combat HIV/AIDS stigma and raise awareness of the relevance of HIV/AIDS to Latino communities.

Cost-effectiveness of male circumcision for HIV prevention in a South African setting

BACKGROUND

Consistent with observational studies, a randomized controlled intervention trial of adult male circumcision (MC) conducted in the general population in Orange Farm (OF) (Gauteng Province, South Africa) demonstrated a protective effect against HIV acquisition of 60%. The objective of this study is to present the first cost-effectiveness analysis of the use of MC as an intervention to reduce the spread of HIV in sub-Saharan Africa.

METHODS AND FINDINGS

Cost-effectiveness was modeled for 1,000 MCs done within a general adult male population. Intervention costs included performing MC and treatment of adverse events. HIV prevalence was estimated from published estimates and incidence among susceptible subjects calculated assuming a steady-state epidemic. Effectiveness was defined as the number of HIV infections averted (HIA), which was estimated by dynamically projecting over 20 years the reduction in HIV incidence observed in the OF trial, including secondary transmission to women. Net savings were calculated with adjustment for the averted lifetime duration cost of HIV treatment. Sensitivity analyses examined the effects of input uncertainty and program coverage. All results were discounted to the present at 3% per year. For Gauteng Province, assuming full coverage of the MC intervention, with a 2005 adult male prevalence of 25.6%, 1,000 circumcisions would avert an estimated 308 (80% CI 189-428) infections over 20 years. The cost is 181 dollars (80% CI 117-306 dollars) per HIA, and net savings are 2.4 million dollars (80% CI 1.3 million to 3.6 million dollars). Cost-effectiveness is sensitive to the costs of MC and of averted HIV treatment, the protective effect of MC, and HIV prevalence. With an HIV prevalence of 8.4%, the cost per HIA is 551 dollars (80% CI 344-1,071 dollars) and net savings are 753,000 (80% CI 0.3 million to 1.2 million dollars). Cost-effectiveness improves by less than 10% when MC intervention coverage is 50% of full coverage.

CONCLUSIONS

In settings in sub-Saharan Africa with high or moderate HIV prevalence among the general population, adult MC is likely to be a cost-effective HIV prevention strategy, even when it has a low coverage. MC generates large net savings after adjustment for averted HIV medical costs.

HIV vaccine acceptability among communities at risk: the impact of vaccine characteristics

HIV vaccines offer the best long-term hope of controlling the AIDS pandemic; yet, the advent of HIV vaccines will not ensure their acceptability. We conducted a cross-sectional survey (n=143), incorporating conjoint analysis, to assess HIV vaccine acceptability among participants recruited using multi-site (n=9), venue-based sampling in Los Angeles. We used a fractional factorial experimental design to construct eight hypothetical HIV vaccines, each with seven dichotomous attributes. The acceptability of each vaccine was assessed individually and then averaged across participants. Next, the impact of each attribute on vaccine acceptability was estimated for each participant using ANOVA and then analyzed across participants. Acceptability of the eight hypothetical HIV vaccines ranged from 33.2 (S.D. 34.9) to 82.2 (S.D. 31.3) on a 0-100 scale; mean=60.0 (S.D. 21.9). Efficacy had the greatest impact on acceptability (22.7; CI: 18.5-27.1; p<0.0001), followed by cross-clade protection (12.5; CI: 8.7-16.3, p<0.0001), side effects (11.5; CI: 7.4-15.5; p<0.0001), and duration of protection (6.1; CI: 3.2-9.0; p<.0001). Route of administration, number of doses and cost were not significant. Low acceptability of "partial efficacy" vaccines may present obstacles to future HIV vaccine dissemination. Educational and social marketing interventions may be necessary to ensure broad HIV vaccine uptake.