HIV vaccine trial willingness among injection and non-injection drug users in two urban centres, Barcelona and San Francisco

Willingness to Participate in Hypothetical HIV Vaccine Trial and Associated Factors among People Who Inject Drugs in Dar es Salaam, Tanzania

This study is aimed at assessing the willingness to participate in the HIV vaccine trials and the associated factors among people who inject drugs (PWIDs) in Tanzania. Information about the willingness to participate and the associated factors was collected using interviewer-administered questionnaires at the medication treatment for opioid use disorder (MOUD) clinic in Dar es Salaam. Data analysis was performed using the IBM SPSS Statistic 20. The mean age of respondents was 36.7, and the standard deviation (SD) was ±7.2. The majority of respondents (68%) had primary education, and a high proportion of them were single (61.5%). More than one-third (37.9%) shared needles and syringes. Most (87.3%) had more than three sexual partners, and almost half (51.4%) did not use condoms during sexual intercourse with nonregular partners. About 63% had knowledge of HIV transmission while 27% had heard about HIV vaccine trials. Generally, 76% of the respondents expressed willingness to participate in future HIV vaccine trials regardless of prior knowledge of HIV vaccine trials. Willingness to participate in HIV vaccine trials was not associated with education level, people living with, knowledge about HIV transmission, awareness of HIV vaccine trials, sharing of syringe/needles, and number of sexual partners. Only older age (OR = 1.6, 95%CI = 1.01, 2.6) and condom use (OR = 0.49, 95%CI = 0.26, 0.97) showed an association with willingness. However, after performing logistic regression with factors at p value ≤ 0.2 to ascertain the other factors on the effects of age, condom use, education level, and sharing of needles/syringes, the results were not statistically significant. Although participants reported a high willingness to participate in hypothetical HIV vaccine trials, no definitive conclusion can be drawn about the associated factors. Further studies with intensive educational programs are needed to investigate the factors on willingness to participate in actual HIV vaccine trials among PWIDs.

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.

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

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

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.