Willingness of Injection Drug Users to Participate in an HIV Vaccine Efficacy Trial in Bangkok, Thailand

Abstract

We assessed willingness to participate in an HIV recombinant gp120 bivalent subtypes B/E candidate vaccine efficacy trial among 193 injection drug users (IDUs) attending drug treatment clinics in Bangkok, Thailand. IDUs previously enrolled in a prospective cohort study were invited to group sessions describing a potential trial, then completed questionnaires assessing comprehension and willingness to participate. A week later, they completed a follow-up questionnaire that again assessed comprehension and willingness to participate, as well as barriers to and positive motives for participation, with whom (if anyone) they talked about the information, and whether others thought participation was a good, bad, or neutral idea. At baseline, 51% were definitely willing to participate, and at follow-up 54%; only 3% were not willing to participate at either time. Comprehension was high at baseline and improved at follow-up. Participants who viewed altruism, regular HIV tests, and family support for participation as important were more willing to volunteer. Frequency of incarceration and concerns about the length of the trial, possible vaccine-induced accelerated disease progression, and lack of family support were negatively associated with willingness. Overall, IDUs comprehended the information needed to make a fully informed decision about participating in an rgp120 vaccine efficacy trial and expressed a high level of willingness to participate in such a trial.

Willingness of Chinese injection drug users to participate in HIV vaccine trials

“…However, the protective effect of any available HIV candidate vaccines is still uncertain; the high response rates in both groups may reflect insufficient information in relation to the experimental characteristics of the hypothetical vaccine. Like in other Asian studies [21], social relationship and fear of the exclusion of community were found to be independent predictors for WTP in our study sample. It is suggested that efforts should be made to increase awareness of the importance and reduce the stigma of participating in HIV vaccine trials among both high-risk groups, who are potential vaccine trial participants, and general population whose attitudes may affect participants' decision.…”

“…This percentage is higher than other studies among IDUs in both Asian and western countries [21][22]. Besides IDUs, men who have sex with men (MSM) and women at heterosexual risk have also been most involved in HIV vaccine trials.…”

Willingness to Participate (WTP) in HIV Vaccine Trials among Itinerant Female Hairdressers in Ibadan, Nigeria

“…This indicates a need to develop strategies and materials for those in secondary or vocational school and ensuring that all presentations are well adapted to the target audience. Such recommendations had been made in similar studies [16]. The level of willingness to participate found in the present investigation was slightly higher than that which have been found in a similar study in the Northern part of Nigeria and Uganda [7,17].…”

Factors Associated with Willingness to Participate in HIV Vaccine Trials among High-Risk Populations in South India

“…Knowledge and attitude toward HIV vaccines are among the factors that may influence participation in trials and the eventual acceptability of efficacious vaccines. [10][11][12][13][14][15] We found a significant difference in the level of knowledge before and after vaccine education in our study sample. However, only 63% of the participants understood that initial HIV vaccines are expected to be only partially efficacious.…”

“…Previous studies suggest that sociodemographic characteristics and risk behavior are associated with WTP. 10,11,[13][14][15]22 According to a report from a WHO-UNAIDS consultation, 23 WTP in trials varies depending on educational level, perception of risk, and age. Altruism and a desire for protection are common motivations for participation and vaccine safety is usually the major concern.…”