Knowledge about vaccines and willingness to participate in preventive HIV vaccine trials: a population-based study, Rakai, Uganda

The willingness to participate in biomedical research involving human beings in low- and middle-income countries: a systematic review

Objectives

To systematically review reasons for the willingness to participate in biomedical human subjects research in low‐ and middle‐income countries (LMICs).

Methods

Five databases were systematically searched for articles published between 2000 and 2017 containing the domain of ‘human subjects research’ in ‘LMICs’ and determinant ‘reasons for (non)participation’. Reasons mentioned were extracted, ranked and results narratively described.

Results

Ninety‐four articles were included, 44 qualitative and 50 mixed‐methods studies. Altruism, personal health benefits, access to health care, monetary benefit, knowledge, social support and trust were the most important reasons for participation. Primary reasons for non‐participation were safety concerns, inconvenience, stigmatisation, lack of social support, confidentiality concerns, physical pain, efficacy concerns and distrust. Stigmatisation was a major concern in relation to HIV research. Reasons were similar across different regions, gender, non‐patient or patient participants and real or hypothetical study designs.

Conclusions

Addressing factors that affect (non‐)participation in the planning process and during the conduct of research may enhance voluntary consent to participation and reduce barriers for potential participants.

Reported willingness to participate in a hypothetical HIV vaccine trial and its translation to actual participation among healthy adults-Experience from Kenya

Objective

To evaluate initial reported willingness to participate in a hypothetical HIV vaccine clinical trial and actual participation of volunteers in a longitudinal observational study.

Methods

We recruited HIV negative male and female volunteers aged 18–45 years into a longitudinal observational study at KAVI–ICR Kangemi in Kenya, to serve as a pool from which to draw participants into a phase I HIV vaccine clinical trial. A structured questionnaire was used to collect information regarding willingness to join a HIV vaccine clinical trial in the future. Study follow-up visits were every 6 months.

Results

A total of 105 participants were screened and 100 (M46:F54) were enrolled into the observational study. Ninety- four per cent of those enrolled expressed willingness to participate in a future HIV vaccine trial. Altruism and desire to learn the body’s response to the vaccine were the most motivating factors at 40% and 25% respectively. At the onset of a 40-person phase I HIV vaccine trial, 86 observational study participants who had previously expressed willingness to participate were contacted but only 26 (30%) came for information. All 26 consented to participate and after screening for eligibility, 24 were eligible. Of the 24, 15 were enrolled. These numbers were not adequate; hence the vaccine trial employed other recruitment methods to meet the deficit.

Conclusion

Observational “pools” of cohorts may not provide adequate number of participants into vaccine clinical trials even if they report willingness; therefore supplementary recruitment methods such as direct community recruitment, passive approach, and snowballing need to be in place.

Community Members' Perceptions of Enablers and Inhibitors to Participation in HIV Vaccine Trials

We present the findings of a qualitative investigation into the factors that may enable or inhibit participation in a future HIV vaccine trial. Thirty-seven semi-structured interviews and two focus groups were conducted with trial site community members who had attended HIV vaccine education workshops conducted by the community involvement programme of the South African AIDS Vaccine Initiative (SAAVI). Our findings indicate that enablers and inhibitors to participation in HIV vaccine trials may. be further classified as either abstract or concrete. Each sub-theme was classified as an abstract inhibitor, abstract enabler, concrete inhibitor, or concrete enabler. Abstract inhibitors were fear of illness or death, lack of information about HIV/AIDS and HIV vaccines, and an HIV vaccine trial's association with HIV/AIDS. Abstract enablers were participants' reported sense of altruism and quality of life issues, such as protection from becoming infected with HIV. Concrete inhibitors were the monetary costs associated with participation, fear of being tested for HIV and receiving test results, negative reactions from family and community members, time delays between receiving trial participation information and actual enrolment, and a general mistrust of researchers. Concrete enablers were practicalities and convenience, financial rewards, a safe testing environment, positive family reactions to trial participation, the different levels of participation available to different members of the community, the salience of HIV in communities, positive community reactions to vaccine trials, and the presence of role models. In addition to these quadrants, the enablers and inhibitors have also been located within a contextual framework that includes the individual; family, community, and societal levels. Our research contributes to an understanding of the concerns of potential HIV vaccine trial participants within the South African context. Our findings illustrate the applicability of international research to proposed vaccine-trial activities in South Africa and should, therefore, inform the development and implementation of successful community preparedness activities.

Motivations to participate in a Phase I/II HIV vaccine trial: A descriptive study from Dar es Salaam, Tanzania

Background

The search for an efficacious HIV vaccine is a global priority. To date only one HIV vaccine trial (RV144) has shown modest efficacy in a phase III trial. With existing different HIV-1 subtypes and frequent mutations, multiple trials are needed from different geographical sites particularly in sub-Saharan Africa where most HIV infections occur. Thus, motivations to participate in HIV vaccine trials among Tanzanians need to be assessed. This paper describes the motives of Police Officers who showed great interest to volunteer in HIVIS-03 in Dar es Salaam, Tanzania.

Methods

A descriptive cross-sectional study was conducted among Police Officers who showed interest to participate in the HIVIS-03, a phase I/II HIV vaccine trial in Dar es Salaam. Prior to detailed training sessions about HIV vaccine trials, the potential participants narrated their individual motives to participate in the trial on a piece of paper. Descriptive analysis using content approach and frequency distributions were performed.

Results

Of the 265 respondents, 242 (91.3 %) provided their socio-demographic characteristics as well as reasons that would make them take part in the proposed trial. Majority, (39.7 %), cited altruism as the main motive. Women were more likely to volunteer due to altruism compared to men (P < 0.01). Researchers’ explanations about HIV/AIDS vaccine studies motivated 15.3 %. More men (19.6 %) than women (1.7 %) were motivated to volunteer due to researchers’ explanations (P < 0.001). Also, compared to other groups, those unmarried and educated up to secondary level of education were motivated to volunteer due to researchers’ explanation (P < 0.05). Other reasons were: desire to become a role model (18.6 %); to get knowledge for educating others (14.0 %); to cooperate with researchers in developing an HIV vaccine (9.5 %); to get protection against HIV infection (7.0 %), and severity of the disease within families (6.2 %). These results were supported by testimonies from both men and women.

Conclusions

Participation in an HIV vaccine trial in a Tanzanian context is likely to be influenced by altruism and comprehensive education about the trial. Gender differences, marital status and education level need to be considered to enhance participation in future HIV vaccine trials.

HIV Type 1 Disease Progression to AIDS and Death in a Rural Ugandan Cohort Is Primarily Dependent on Viral Load Despite Variable Subtype and T-Cell Immune Activation Levels

BACKGROUND

Untreated human immunodeficiency virus type 1 (HIV) infection is associated with persistent immune activation, which is an independent driver of disease progression in European and United States cohorts. In Uganda, HIV-1 subtypes A and D and recombinant AD viruses predominate and exhibit differential rates of disease progression.

METHODS

HIV-1 seroconverters (n = 156) from rural Uganda were evaluated to assess the effects of T-cell activation, viral load, and viral subtype on disease progression during clinical follow-up.

RESULTS

The frequency of activated T cells was increased in HIV-1-infected Ugandans, compared with community matched uninfected individuals, but did not differ significantly between viral subtypes. Higher HIV-1 load, subtype D, older age, and high T-cell activation levels were associated with faster disease progression to AIDS or death. In a multivariate Cox regression analysis, HIV-1 load was the strongest predictor of progression, with subtype also contributing. T-cell activation did not emerge an independent predictor of disease progression from this particular cohort.

CONCLUSIONS

These findings suggest that the independent contribution of T-cell activation on morbidity and mortality observed in European and North American cohorts may not be directly translated to the HIV epidemic in East Africa. In this setting, HIV-1 load appears to be the primary determinant of disease progression.

Willingness to participate in HIV therapeutic vaccine trials among HIV-infected patients on ART in China

Background

More and more HIV therapeutic vaccines will enter clinical trials; however, little is known about the willingness to participate (WTP) in HIV therapeutic vaccine trials among HIV-positive individuals.

Objective

To investigate the WTP in HIV therapeutic vaccine trials among Chinese HIV-infected patients.

Methods

We conducted a cross-sectional survey on HIV-positive inpatients and outpatients at Shanghai Public Health Center. A total of 447 participants were recruited into this study. Following an introduction with general information on HIV therapeutic vaccine and its potential effectiveness and side effects, each participant completed a questionnaire in a self-administered form. The questionnaires covered demographics, high-risk behaviors, clinical characteristics and willingness to participate in HIV therapeutic vaccine trial.

Results

The overall willingness to participate in HIV therapeutic vaccine trials was 91.5%. Interestingly, multivariate logistic regression analyses demonstrated that the willingness was higher for those sexually infected by HIV (odds ratio [OR]: 4.36; 95% confidence interval [CI]: 1.53–12.41), diagnosed as HIV-1 infection for greater than 5 years (OR: 7.12, 95% CI: 1.83–27.76), and with the presence of infectious complications (OR: 2.75; 95% CI: 1.02–7.45). The primary reason for participation was to delay or reduce antiretroviral treatment (ART) and to avoid ART side effects (76.6%), and then followed by delaying disease progression (74.9%), increasing immune response to suppress opportunistic infections (57.7%) and preventing the development of drug resistance (37.1%). Reasons for unwillingness to participate mainly included concern for safety (37.0%), lack of knowledge on therapeutic vaccine (33.3%), and satisfaction with ART effectiveness (22.2%).

Conclusions

The WTP in HIV therapeutic vaccine trials was high among HIV-infected Chinese patients. HIV⁺ subjects who acquired infection through sexual contact and who were diagnosed for more than 5 years may represent a good candidate population for enrollment in therapeutic vaccine trials.

Field evaluation of PIMA point-of-care CD4 testing in Rakai, Uganda

Objective

To assess the accuracy of PIMA Point-of-Care (POC) CD4 testing in rural Rakai, Uganda.

Methods

903 HIV positive persons attending field clinics provided a venous blood sample assessed on site using PIMA analyzers per manufacturer's specifications. The venous samples were then run on FACSCalibur flow cytometry at a central facility. The Bland–Altman method was used to estimate mean bias and 95% limits of agreement (LOA). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated for a CD4 threshold of <350 and <500 cells/uL for antiretroviral eligibility.

Results

There was a high correlation between PIMA and FACSCalibur CD4 counts (r = 0.943, p<0.001). Relative to FACSCalibur, the PIMA POC CD4 had negative mean bias of −34.6 cells/uL (95% LOA: −219.8 to 150.6) overall. The dispersion at CD4<350 cells/uL was 5.1 cells/uL (95% LOA: −126.6 to 136.8). For a threshold of CD4<350 cells/uL, PIMA venous blood had a sensitivity of 88.6% (95%CI 84.8–92.4%), specificity of 87.5% (95%CI 84.9–90.1%), NPV of 94.9% (95%CI 93.1–96.7%), and PPV of 74.4% (95%CI 69.6–79.2%). PIMA sensitivity and PPV significantly increased to 96.1% and 88.3% respectively with increased threshold of 500 cells/uL.

Conclusions

Overall, PIMA POC CD4 counts demonstrated negative bias compared to FACSCalibur. PIMA POC sensitivity improved significantly at a higher CD4 threshold of 500 than a 350 cells/uL threshold.

Factors that influence the willingness of young adults in Dar es Salaam, Tanzania, to participate in phase I/II HIV vaccine trials

Background

HIV/AIDS continues to destroy the lives of young people especially in low-income countries. The inclusion of youths in HIV vaccine trials is of utmost importance in obtaining an effective vaccine that is acceptable to them.

Objective

To characterize the willingness of young adults in Tanzania to participate in an HIV vaccine trial and the factors that influence this willingness.

Design

Four hundred and fifty young adults who visited a youth-friendly Infectious Diseases Clinic (IDC) from February 2012 to September 2012 completed a self-administered questionnaire concerning sociodemographic information, their knowledge about and perception of HIV vaccine studies, and the availability of social support.

Results

Of our participants, 50.6% expressed willingness to participate in HIV vaccine trials, and this willingness was positively correlated with having some knowledge about HIV vaccine studies (AOR, 2.2; 95% CI: 1.4–3.4), a positive perception toward such studies (AOR, 2.3; 95% CI: 1.5–3.6), having a relationship with someone who could help them make a decision (AOR, 2.5; 95% CI: 1.3–4.9), and age at the time of sexual debut (AOR, 2.6; 95% CI 1.0–6.7) for 15- to 19-year-olds and (AOR, 2.7; 95% CI 1.0–7.1) for older participants.

Conclusions

The participants exhibited a moderate willingness to participate in HIV vaccine trials, which was associated with a positive perception of and some knowledge about such trials, having a relationship with someone who might influence their decision as well as age at time of sexual debut. More efforts should be made to inform the youths about specific HIV vaccine trials and related matters, as well as to engage significant others in the decision-making process.

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.

HIV type 1 polymerase gene polymorphisms are associated with phenotypic differences in replication capacity and disease progression

BACKGROUND

Determinants of intersubtype differences in human immunodeficiency virus type 1 (HIV-1) clinical disease progression remain unknown.

METHODS

HIV-1 subtype was independently determined for 5 separate genomic regions in 396 HIV-1 seroconverters from Rakai, Uganda, using a multiregion hybridization assay. Replication capacities (RC) in samples from a subset of 145 of these subjects were determined. HIV-1 genomic regions and pol RC were examined for association with disease progression. Amino acid polymorphisms were examined for association with pol RC.

RESULTS

In multivariate analyses, the hazard for progression to the composite end point (defined as a CD4(+) T-cell count <250 cells/mm(3), antiretroviral therapy initiation, or death) among patients with subtype D pol infection was 2.4 times the hazard for those infected with subtype A pol infection (P = .001). Compared with subtype A pol (the reference group), the hazard for progression to the composite end point for subtype D pol infection with a pol RC >67% (ie, the median pol RC) was significantly greater (HR, 4.6; 95% confidence interval [CI], 1.9-11.0; P = .001), whereas the hazard for progression to the composite end point for subtype D pol infection with a pol RC ≤67% was not significantly different (HR, 2.2; 95% CI, 1.0-4.9; P = .051). Amino acid substitutions at protease positions 62 and 64 and at reverse transcriptase position 272 were associated with significant differences in pol RC.

CONCLUSIONS

HIV-1 pol gene intersubtype and RC differences are associated with disease progression and may be influenced by amino acid polymorphisms.

High HIV-1 prevalence, risk behaviours, and willingness to participate in HIV vaccine trials in fishing communities on Lake Victoria, Uganda

Introduction

HIV epidemics in sub-Saharan Africa are generalized, but high-risk subgroups exist within these epidemics. A recent study among fisher-folk communities (FFC) in Uganda showed high HIV prevalence (28.8%) and incidence (4.9/100 person-years). However, those findings may not reflect population-wide HIV rates in FFC since the study population was selected for high-risk behaviour.

Methods

Between September 2011 and March 2013, we conducted a community-based cohort study to determine the population representative HIV rates and willingness to participate (WTP) in hypothetical vaccine trials among FFC, Uganda. At baseline (September 2011–January 2012), a household enumeration census was done in eight fishing communities (one lakeshore and seven islands), after which a random sample of 2200 participants aged 18–49 years was selected from 5360 individuals. Interviewer-administered questionnaire data were collected on HIV risk behaviours and WTP, and venous blood was collected for HIV testing using rapid HIV tests with enzyme-linked immunosorbent assay (EIA) confirmation. Adjusted prevalence proportion ratios (adj.PPRs) of HIV prevalence were determined using log-binomial regression models.

Results

Overall baseline HIV prevalence was 26.7% and was higher in women than men (32.6% vs. 20.8%, p<0.0001). Prevalence was lower among fishermen (22.4%) than housewives (32.1%), farmers (33.1%) and bar/lodge/restaurant workers (37%). The adj.PPR of HIV was higher among women than men (adj.PPR =1.50, 95%; 1.20, 1.87) and participants aged 30–39 years (adj.PPR=1.40, 95%; 1.10, 1.79) and 40–49 years (adj.PPR=1.41, 95%; 1.04, 1.92) compared to those aged 18–24 years. Other factors associated with HIV prevalence included low education, previous marriage, polygamous marriage, alcohol and marijuana use before sex. WTP in hypothetical vaccine trials was 89.3% and was higher in men than women (91.2% vs. 87.3%, p=0.004) and among island communities compared to lakeshore ones (90.4% vs. 85.8%, p=0.004).

Conclusions

The HIV prevalence in the general fisher-folk population in Uganda is similar to that observed in the “high-risk” fisher folk. FFC have very high levels of willingness to participate in future HIV vaccine trials.

Enhanced retention strategies and willingness to participate among hard-to-reach female sex workers in Barcelona for HIV prevention and vaccine trials

The potential for implementation of HIV vaccine trials in hard-to-reach female sex workers in an inner city area of Barcelona, Spain was assessed via a study of HIV risk, willingness to participate and the success of retention strategies. In 130 women, serological HIV status, behavioral risk exposures and willingness to participate in future HIV vaccine trials were recorded every six months using a confidential questionnaire. An enhanced retention (ER) strategy was compared with a control retention (CR) strategy comprising the recording of data on appointment cards. HIV seroincidence and retention rates were estimated. Retention rates after 6 and 12 mo of follow-up in the ER group were 76% and 69% respectively compared with 16% and 13% in the CR group. Among the ER group 97% were willing to participate in HIV vaccine trials at baseline and, after 12 mo of follow-up. Willingness was significantly associated with higher HIV risk exposure, and higher education level. Successfully retaining these cohorts over time in settings with a high HIV seroincidence rate is an ongoing challenge that will need to be addressed to ensure participation in future trials. Furthermore, as we have demonstrated, the fact that retaining hard-to-reach populations is difficult should not exclude this target population for HIV vaccine and prevention trials.

Willingness to participate in biomedical HIV prevention studies after the HVTN 503/Phambili trial: a survey conducted among adolescents in Soweto, South Africa

OBJECTIVES

Adolescents may be appropriate for inclusion in biomedical HIV prevention trials. Adolescents' overall willingness to participate (WTP) in biomedical HIV prevention trials was examined, including after the prematurely discontinued phase IIb HVTN 503/Phambili HIV vaccine trial, in Soweto, South Africa.

METHODS

An interview-administered cross-sectional survey was conducted among 506 adolescents (16-18 years) between October 2008 and March 2009. The assessment included WTP in HIV prevention trials, sexual and substance use behavior, and related psychosocial constructs. Multivariate logistic regression analyses examined predictors of WTP in biomedical prevention trials.

RESULTS

The sample primarily consisted of female participants (n = 298, 59%), and 50% of all participants were sexually active. WTP in general was high (93%), with 75% WTP in a vaccine trial after being informed about the HVTN 503/Phambili trial. Less exposure to stressors [odds ratio (OR): 2.8, confidence interval (CI): 1.3 to 6.3] was associated with adolescents' WTP in HIV biomedical prevention trials overall. Those with less exposure to stressors (OR: 1.7, CI: 1.1 to 2.8) and not sexually active (OR: 2.1, CI: 1.4 to 3.3) were predictive of WTP after the HVTN 503/Phambili trial. A higher number of sexual partners were associated with unwillingness to participate more generally (P = 0.039) and specifically after the HIV vaccine trial (P = 0.0004).

CONCLUSIONS

The high level of adolescents' WTP in biomedical prevention trials is encouraging, especially after the prematurely discontinued HVTN 503/Phambili HIV vaccine trial. High-risk youth were less likely to be WTP, although those not yet sexually active were more WTP. Future biomedical HIV prevention trials should address challenges to enrollment of high-risk adolescents who may show less WTP.

Barriers of enrolment in HIV vaccine trials: a review of HIV vaccine preparedness studies

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 infection awareness and willingness to participate in future HIV vaccine trials across different risk groups in Abuja, Nigeria

The purpose of this survey is to generate baseline data on the level of HIV infection awareness and willingness to participate (WTP) in hypothetical vaccine trials, ahead of any trial conduct in Nigeria. In a cross-sectional survey, 500 respondents were interviewed, including sex workers, male motorcycle taxi drivers, students, and the general public. About 153 (30.6%) of the respondents did not believe that correct and consistent use of condom can protect people from getting HIV, while about 66 (13.2%) respondents believed it is possible to get HIV by sharing meal with an infected person. Population groups considered at high risk for HIV were less aware of the disease, however, they were more willing to participate in HIV vaccine trials compared those at low risk of the disease. A total of 55% expressed WTP in a hypothetical vaccine trial after they were informed about it. Age, population group, and ethnicity were significantly associated with WTP.

Balancing collective responsibility, individual opportunities and risks: a qualitative study on how police officers reason around volunteering in an HIV vaccine trial in Dar es Salaam, Tanzania

Background

Results from HIV vaccine trials on potential volunteers will contribute to global efforts to develop an HIV vaccine. The purpose of this study among police officers in Dar es Salaam, Tanzania, was to explore the underlying reasons that induce people to enrol in an HIV vaccine trial.

Methods

We conducted discussions with eight focus groups, containing a total of 66 police officers. The information collected was analyzed using interpretive description.

Results

The results showed that participants were motivated to participate in the trial by altruism, and that the participants experienced some concerns about their participation. They stated that altruism in the fight against HIV infection was the main reason for enrolling in the trial. However, young participants were seriously concerned about a possible loss of close relationships if they enrolled in the HIV vaccine trial. Both men and women feared the effect of the trial on their reproductive biology, and they feared interference with pregnancy norms. They were unsure about risks such as the risks of acquiring HIV infection and of suffering physical harm, and they were unsure of the intentions of the researchers conducting the trial. Further, enrolling in the trial required medical examination, and this led some participants to fear that unknown diseases would be revealed. Other participants, however, saw an opportunity to obtain free health services.

Conclusions

We have shown that specific fears are important concerns when recruiting volunteers to an HIV vaccine trial. More knowledge is needed to determine participants' views and to ensure that they understand the conduct of the trial and the reasons it is being carried out.

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.

HIV-1 subtypes and differences in heterosexual HIV transmission among HIV-discordant couples in Rakai, Uganda

OBJECTIVE

To determine whether heterosexual transmission of HIV differs according to HIV-1 subtype.

DESIGN

A retrospective observational cohort.

METHODS

HIV-1 subtype effects on heterosexual HIV-1 transmission were determined among 268 HIV-discordant couples retrospectively identified from a population cohort in Rakai, Uganda. HIV-1 subtype (gag and gp41 sequencing and multiregion hybridization assay) and viral loads (reverse transcriptase PCR) were determined. Adjusted incidence rate ratios (adj IRR) of HIV transmission by subtype were estimated by multivariable Poisson regression adjusting for characteristics of index HIV-positive and HIV-negative partners.

RESULTS

Adjusting for index HIV-positive partners' age, viral load, stage of disease, genital ulcer disease, and HIV-negative partners' genital ulcer disease and nonuse of condoms, subtype A viruses were associated with a higher rate of transmission than subtype D [adj.IRR 1.98, 95% confidence interval (CI) 1.17-3.34], but no differences in transmission were observed between recombinant viruses and subtype D (aIRR 1.53, P = 0.25). Index-positive partners' age less than 30 years (adj.IRR 3.44, 95% CI 1.75-6.78) and viral load (adj.IRR 2.37, 95% CI 1.75-3.21), and index-negative partners' genital ulcer disease (adj.IRR 1.71, 95% CI 1.08-2.70) and nonuse of condoms (adj.IRR 1.94, 95% CI 1.15-3.28) were significant determinants of HIV transmission.

CONCLUSION

In Rakai, Uganda, subtype A viruses have a significantly higher rate of heterosexual transmission than subtype D viruses. Differential subtype transmission efficiency may be important for HIV vaccine evaluation and could contribute to subtype-specific HIV epidemics in sub-Saharan Africa.

Geographic HIV type 1 subtype distribution in Rakai district, Uganda

To analyze HIV-1 subtype distribution, sequence analysis was performed on serum specimens obtained in 1994 from the Rakai Health Sciences community cohort in Uganda. Portions of gag-p24 and env-gp41 were sequenced and HIV subtype was determined for 773 subjects residing in 10 community clusters in rural Uganda. Subtypes A (17%) and D (70%) were the most common strains in the population. Subtype distribution varied by geographic region with significantly more subtype A in northern community clusters compared with southern clusters (21% vs. 8%, p < 0.001) and more subtype D in southern clusters compared with northern clusters (78% vs. 65%, p < 0.008). These data illustrate the geographic complexity of subtype variation, which has important implications for HIV-1 vaccine design.

Willingness to volunteer in a Phase I/II HIV vaccine trial: a study among police officers in Dar es Salaam, Tanzania

Background

As HIV infection continues to devastate low-income countries, efforts to search for an effective HIV vaccine are crucial. Therefore, participation in HIV vaccine trials will be useful for the development of a preventive vaccine that will work and thus reduce the global HIV epidemic.

Objective

The objective of this study was to analyse the willingness to volunteer (WTV) in a Phase I/II HIV vaccine trial among police officers in Dar es Salaam, Tanzania.

Design

We included a convenience sample of 329 participants (79% males) from sensitisation workshops that were held once at each of the 32 police stations. Participants were recruited from 23 stations which were included according to availability. Data about personal characteristics, general HIV and AIDS knowledge and sexual behaviour, attitudes towards vaccines and willingness to participate in the HIV vaccine trial were obtained through an interview-administered questionnaire with both closed and open-ended questions.

Results

Overall, 61% of the participants expressed WTV in HIV vaccine trials. WTV was significantly associated with: positive attitude towards use of effective vaccine, Odds ratio (OR), 36.48 (95% CI: 15.07–88.28); the intention to tell others about one's decision to participate in the trial, OR, 6.61 (95% CI: 3.89–11.24); Tanzania becoming a partner in developing the vaccine, OR, 4.28 (95% CI: 2.28–8.03); having an extra sexual partner, OR, 3.05 (95% CI: 1.63–5.69); perceived higher risk of getting HIV infection, OR, 2.11 (95% CI: 1.34–3.33); and high knowledge about HIV and AIDS, OR, 1.92 (95% CI: 1.22–3.01).

Conclusion

The results indicated that a majority of police officers in this study were willing to participate in HIV vaccine trials. However, there is a need to provide the respondents with precise information about the purpose of a Phase I/II HIV vaccine trial and the fact that it does not protect against HIV infection, in order to avoid increasing risky behaviour.

Determinants of participation in HIV clinical trials: the importance of patients' trust in their provider

PURPOSE

To investigate the factors that contribute to willingness to participate in HIV clinical trials and to determine the impact of a brief intervention on willingness to participate.

METHODS

115 consecutive outpatients receiving HIV primary care participated in this prospective study. Each patient completed a questionnaire about clinical trials and met with a research assistant who discussed the purpose of clinical trials. After the educational intervention, participants completed a second questionnaire and responses from the two surveys were compared.

RESULTS

115 patients were enrolled (56% had previously enrolled in a clinical trial; 50% of whom were currently enrolled in a trial); 92% would consider participating in a future clinical trial. Increased patient trust in the provider was associated with increased willingness to participate in a trial. After the intervention, 94% indicated that they would be willing to be contacted about a clinical trial for which they may be eligible and 85% preferred to be contacted by their primary physician.

CONCLUSIONS

Patients' trust in their provider may predict willingness to participate in clinical trial. Providing HIV-infected patients and their providers with information about HIV clinical trials at the site where they receive care may increase participation rates in HIV clinical trials.

Future HIV vaccine acceptability among young adults in South Africa

Developing and disseminating a preventive HIV vaccine is a primary scientific and public health objective. However, little is known about HIV vaccine acceptability in the high-prevalence setting of South Africa- where young adults are likely to be targeted in early dissemination efforts. This study reports on six focus groups ( n = 42) conducted in 2007 with South Africans aged 18 to 24 years. A deductive framework approach is used to identify key motivators and barriers to future HIV vaccine uptake. Participants identify HIV testing, HIV stigma, mistrust of the health care system, and concerns about sexual disinhibition as barriers to vaccine uptake. For women, family members and friends are strong motivators for vaccine uptake, whereas men are more likely to see vaccines as an opportunity to stop using HIV prevention strategies such as condoms and partner reduction. Implications of these findings for developing HIV vaccine dissemination strategies and policy in South Africa are discussed.

Willingness to participate in preventive HIV vaccine trials in a community-based cohort in south western Uganda

OBJECTIVES

To assess willingness to participate in HIV vaccine trials and possible barriers to participation.

METHODS

Questionnaire survey of participants completing a 2-year community-based HIV Vaccine Preparedness Study, followed by cross sectional analysis of data.

RESULTS

95% of participants were willing to participate in a trial with similar attributes to the Vaccine Preparedness Study. Certain hypothetical trial attributes significantly reduced willingness to participate: The requirement to delay pregnancy (for females) had the largest effect, reducing willingness to participate from 97% to 23% (P < 0.0001). Larger blood draws had the second largest effect: 95-55% (P < 0.0001). The possibility of receiving either candidate vaccine or placebo had the third largest effect: 95-73% (P < 0.0001). Monthly study visits had the fourth largest effect: 95-92% (P < 0.0001). Trial duration longer than 2 years had the least effect: 95-93% (P = 0.0025). Combined attributes reduced willingness to participate from 95% to 43% (McNemar's chi(2) = 521.00; P < 0.0001) overall and 97-11% (McNemar's chi(2) = 531.00; P < 0.0001) for female participants. Physical harm concerns (adjusted OR = 34.9; 95% CI, 10.4-118) and a low risk behaviour index (adjusted OR = 0.09; 95% CI, 0.01-0.73) were associated with unwillingness to participate.

CONCLUSIONS

We found a high level of willingness to participate in HIV vaccine trials in this population. However, certain HIV vaccine trial requirements were associated with reduced willingness to participate. Community as well as individual concerns will have to be carefully addressed in planned HIV vaccine trials.

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

The present study sought to determine whether the Theory of Planned Behaviour predicted stated hypothetical willingness to participate (WTP) in future Phase III HIV vaccine trials among South African adolescents. Hierarchical logistic regression analyses showed that The Theory of Planned Behaviour (TPB) significantly predicted WTP. Of all the predictors, Subjective norms significantly predicted WTP (OR = 1.19, 95% C.I. = 1.06-1.34). A stepwise logistic regression analysis revealed that Subjective Norms (OR = 1.19, 95% C.I. = 1.07-1.34) and Attitude towards participation in an HIV vaccine trial (OR = 1.32, 95% C.I. = 1.00-1.74) were significant predictors of WTP. The addition of Knowledge of HIV vaccines and HIV vaccine trials, Perceived self-risk of HIV infection, Health-promoting behaviours and Attitudes towards HIV/AIDS yielded non-significant results. These findings provide support for the Theory of Reasoned Action (TRA) and suggest that psychosocial factors may play an important role in WTP in Phase III HIV vaccine trials among adolescents.

Community perspectives on the ethical issues surrounding adolescent HIV vaccine trials in South Africa

Adolescents globally are at high risk for HIV acquisition and are the targets of HIV prevention interventions such as HIV vaccines. In order to understand stakeholders' attitudes towards the ethical issues of adolescent involvement in HIV vaccine trials, we conducted focus group discussions with key members of a semi-urban, informal Cape Town community with high HIV prevalence in which HIV vaccine trials are taking place. Themes were identified from focus group transcripts by four researchers, and included necessity of guardian consent, age of independent consent, and confidentiality of in-trial medical results. In general, ethical adolescent HIV vaccine trials will be feasible in this community.

Adolescent and adult participation in an HIV vaccine trial preparedness cohort in South Africa

PURPOSE

The importance of involving adolescents in HIV prevention trials has been recognized, but there have been few experiences reported from sub-Saharan Africa. We analyzed adult and adolescent data from a cohort study conducted to assess the feasibility of involving adolescents and adults in HIV vaccine-related studies.

METHODS

Two hundred HIV-negative participants aged 16 to 40 years were enrolled, including 86 (43%) adolescents. At baseline, sexual risk behavior and willingness to participate (WTP) in future HIV vaccine trials questionnaires were administered. Three monthly HIV counseling, pregnancy, HIV and syphilis tests were performed. Risk questionnaires were repeated at 6 months and WTP at 12 months.

RESULTS

No significant difference in retention between adults (83%) and adolescents (87%) was noted (p = .58). Initially, more adults (40%) reported WTP compared to adolescents (13%) (p < .001). At the end of the study both groups reported higher levels of WTP; increasing to 40% among adolescents. HIV incidence during the study was 9.2 infections per 100 person-years (95% confidence interval [CI]: 4.4-19.2) among adolescents compared to 5.8 (95% CI 2.6-12.9) in adults (p = .42).

CONCLUSIONS

Retention of high-risk HIV-negative adolescents in a cohort study is feasible. Following education, adolescents reported improved WTP. The high HIV incidence rate in adolescents highlights the importance of including this group in prevention trials.

Effect of human immunodeficiency virus Type 1 (HIV-1) subtype on disease progression in persons from Rakai, Uganda, with incident HIV-1 infection

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) subtypes differ in biological characteristics that may affect pathogenicity.

METHODS

We determined the HIV-1 subtype-specific rates of disease progression among 350 HIV-1 seroconverters. Subtype, viral load, and CD4(+) cell count were determined. Cox proportional hazards regression modeling was used to estimate adjusted hazard ratios (HRs) of progression to acquired immunodeficiency syndrome (AIDS) (defined as a CD4(+) cell count of < or =250 cells/mm(3)) and to AIDS-associated death.

RESULTS

A total of 59.1% of study subjects had subtype D strains, 15.1% had subtype A, 21.1% had intersubtype recombinant subtypes, 4.3% had multiple subtypes, and 0.3% had subtype C. Of the 350 subjects, 129 (37%) progressed to AIDS, and 68 (19.5%) died of AIDS. The median time to AIDS onset was shorter for persons with subtype D (6.5 years), recombinant subtypes (5.6 years), or multiple subtypes (5.8 years), compared with persons with subtype A (8.0 years; P = .022). Relative to subtype A, adjusted HRs of progression to AIDS were 2.13 [95% confidence interval {CI}, 1.10-4.11] for subtype D, 2.16 [95% CI, 1.05-4.45] for recombinant subtypes, and 4.40 [95% CI, 1.71-11.3] for multiple subtypes. The risk of progression to death was significantly higher for subtype D (adjusted HR, 5.65; 95% CI, 1.37-23.4), recombinant subtypes (adjusted HR, 6.70; 95% CI, 1.56-28.8), and multiple subtypes (adjusted HR, 7.67; 95% CI, 1.27-46.3), compared with subtype A.

CONCLUSIONS

HIV disease progression is affected by HIV-1 subtype. This finding may impact decisions on when to initiate antiretroviral therapy and may have implications for future trials of HIV-1 vaccines aimed at slowing disease progression.

Personal and community benefits and harms of research: views from Rakai, Uganda

OBJECTIVES

To assess what individuals in low-income countries perceive as benefits and harms of population-based HIV/STD research.

DESIGN

A total of 811 research participants, research decliners, and community opinion leaders in the Rakai District, Uganda were surveyed. Types of personal and community benefits and harms, as well as rates of reporting great personal and community benefit were assessed.

METHODS

Using logistic regression, demographic characteristics, participant and opinion leader status, use of Rakai Health Sciences Program (RHSP) services, and perceived research effects were entered as predictors of reported great personal and great community benefit.

RESULTS

Most respondents thought that RHSP research was of great personal (85%) and community (88%) benefit. The perception that the RHSP was a great personal benefit was correlated with female sex, post-secondary education, frequent use of RHSP-sponsored medical services, health knowledge gains, and increased hope for future health improvements. Persons of non-Baganda ethnicity and 30-39 year-olds were less likely to believe research was personally beneficial. Regarding research as a great community benefit was associated with reported health knowledge gains, greater hope for Rakai residents' future health, and local economic benefit. Decliners were the most likely to report a personal harm, while community opinion leaders identified community harms at the highest rates.

CONCLUSIONS

The majority of Rakai residents report that HIV/STD research has enhanced their own and their communities' welfare. Different factors were associated with the belief that research is a personal versus community benefit. Variations in participant, decliner, and community opinion leader perceptions highlight inadequacies of current community consultation mechanisms.

Local understanding of an HIV vaccine and its relationship with HIV-related stigma in the Dominican Republic

The purpose of this study was to explore local perceptions and experiences regarding vaccines in general and HIV vaccines and vaccine trials in the Dominican Republic. In-depth interviews were carried out with 25 participants representing two study groups: (1) individuals considered at high risk for HIV infection including female sex workers and male STI clinic attendees and (2) individuals considered at low risk of HIV infection including women and men recruited at a general outpatient clinic. Across the groups, participants often characterized vaccines in general as having both preventive and curative properties. In turn, one of the most salient concerns regarding the receipt of an HIV vaccine was the fear that one would be labelled 'HIV positive' and stigmatized, as the vaccine may be perceived as a cure for those already infected. These findings suggest the importance of individual and community level education to clarify the nature and mechanisms of the given HIV vaccine being tested. Social support and counselling services should also accompany HIV vaccine trials and distribution plans to assist individuals in determining if and how they communicate their participation and/or receipt of an HIV vaccine to others and manage potential negative social reactions.

Sexual risk factors associated with volunteering for HIV vaccine research in South Africa

There are few data on how the risk profiles of individuals who volunteer for HIV vaccine research compare to the general population from which participants are recruited. This study contrasts demographic and sexual risk behaviours among volunteers in an HIV vaccine preparedness cohort with data from a cross-sectional community survey conducted in the same peri-urban community during the same time period. For the HIV vaccine preparedness cohort, structured questionnaires were administered to 140 HIV-negative individuals aged between 16 and 40 years. A questionnaire with identical measures was self-administered in a cross-sectional community survey of 583 randomly selected individuals within the same age range. Compared to the local community sample, individuals who volunteered for the HIV vaccine preparedness cohort were younger (adjusted odds ratio = 0.48; 95% CI = 0.28-0.82), more likely to have had a sexually transmitted disease (adjusted odds ratio = 1.75; 95% CI = 1.03-2.99) and less likely to use condoms (adjusted odds ratio = 0.51; 95% CI = 0.3-0.86). Cohort participants were also more likely to perceive themselves and their partners to be at risk of HIV infection, though these associations did not persist in multivariate analysis. These findings suggest that volunteers for vaccine-related research may be at greater risk of HIV infection than the general population from which they are recruited.

Adolescent HIV prevalence, sexual risk, and willingness to participate in HIV vaccine trials

PURPOSE

To determine human immunodeficiency virus (HIV) prevalence, sexual risk behaviors, and attitudes toward HIV vaccine trials among 11-19 year-olds in a peri-urban community near Cape Town, South Africa.

METHODS

We performed HIV antibody testing on oral transudate, and assessed sexual risk behaviors and willingness to participate in HIV vaccine trials using self-administered questionnaires.

RESULTS

Of the 510 adolescents selected, 356 (73%) participated. The HIV prevalence of the group was 10.6% (95% confidence interval [CI] 7.5-14.4). One-third of adolescents had experienced sexual debut, with a mean age of 14.6 years. Number of lifetime sexual partners was independently associated with HIV infection (odds ratio [OR] = 1.62; 95% CI 1.1-2.3). In a multivariate analysis, increasing age, female gender, and attending school were independently associated with having had sex. The majority of adolescents (79%) were willing to participate in an HIV vaccine trial. Increasing age and length of residence in the community were significantly associated with willingness to participate (OR = 1.19; 95% CI 1.01-1.4 and OR = 1.14; 95% CI 1.03-1.26, respectively).

CONCLUSIONS

The prevalence of HIV and risk behavior among adolescents in this community is high. HIV vaccines are required that target preadolescents. HIV vaccine trials in adolescents in this setting will be facilitated by their willingness to participate.

Community participation in AIDS vaccine trials: Empowerment or science?

For future AIDS vaccines to be successfully tested and implemented, extensive participation in vaccine trials will be necessary. Central to the challenges associated with such participation is concern for protection of participant wellbeing. This short report examines the tension that is sometimes found between the pragmatic need for recruitment into trials, and a more general social good concerning community participation in health. Community empowerment and trial participation are sometimes assumed to go hand in hand, but are potentially contradictory. Recognizing the possible disjunction between empowerment and trial participation allows for clearer discussion of and planning for ethical, scientifically valid trials.

Knowledge and attitudes regarding preventative HIV vaccine clinical trials in Italy: results of a national survey

We carried out a telephone survey to assess willingness to participate in HIV vaccine trials. The survey was conducted by interviewing randomly selected callers to the Italian National AIDS Help line. The questionnaire consisted of four sections: demographic information, knowledge about HIV vaccines and vaccines in general, factors related to participation in HIV vaccine trials, and acceptability of a future HIV vaccine. Over 50% of the sample had adequate knowledge about HIV and vaccines. Among the individuals interviewed, 37% would volunteer for a vaccine trial; those reporting high-risk behaviours were more likely to volunteer. Of the participants, 83% would agree to be vaccinated with a highly effective vaccine, and 92% would pay for the vaccine. Although the limits of telephone surveys should not be neglected, the results of this survey are encouraging.