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Willingness to Participate in HIV Vaccine Research in a Peri-Urban South African Community

Posted on: Wednesday, 29 March 2006, 09:01 CST

By Smit, J; Middelkoop, K; Myer, L; Seedat, S; Et al

Summary: Research on willingness to participate in HIV vaccine trials is important in preparations for HIV vaccine research, but there are few data from sub-Saharan Africa. We interviewed 198 individuals in a peri-urban South African community immediately after enrolment into an HIV vaccine preparedness study on their willingness to participate in hypothetical vaccine trials. Overall 23% of participants (n = 46) said that they would be willing to participate in an HIV vaccine trial. Willingness was associated with increasing age, male gender, and increasing knowledge about vaccines generally and HIV vaccines specifically. In multivariate analysis, a 1-unit increase in HIV vaccine knowledge score was associated with a 10-fold increase in willingness to participate (adjusted odds ratio, 10.72, 95% confidence intervals: 4.40-26.12). These results suggest that while willingness to participate in HIV vaccine trials is relatively low in this setting, educational campaigns may have a substantial impact on individuals' willingness to participate in research.

Keywords: HIV vaccines, participation, clinical trials, South Africa, HIV prevention

Introduction

Despite continuing prevention efforts, the need for an effective vaccine to curb the rapid spread of HIV is widely recognized.1'2 The completion of the first phase III vaccine trials in Thailand and the United States3 has fuelled efforts to prepare for similar studies in other countries. Preparing for vaccine trials across multiple sites is critical in light of the large number of participants required for phase III efficacy studies, and a number of sites in subSaharan Africa are preparing for HIV vaccine research in the near future.

As part of trial preparations, information is required on the attitudes towards HIV vaccines among prospective study participants, most notably their willingness to take part in HIV vaccine research.4 These trials require long-term retention of volunteers, raising concerns about whether the demands of research may discourage participation,5 and stigmatization associated with HIV may present another potential barrier to enrolment.6 In addition, there have been suggestions that willingness to participate in vaccine research may be inversely related to knowledge of HIV vaccines, suggesting that increasing information provided to prospective participants may paradoxically decrease participation. However, there are few insights into this possibility from sub- Saharan Africa where health literacy may be generally lower than in developed countries.

Despite the importance of examining potential participants' willingness to participate in HIV vaccine research, there has been little attention to these issues in South Africa and other countries where the burden of HIV/AIDS is the greatest. We investigated willingness to participate in HIV vaccine research, and the specific associations between vaccine-related knowledge and willingness to participate, among individuals enrolling into an HIV vaccine preparedness study in a periurban South African community.

Methods

The study was conducted in a densely populated settlement outside of Cape Town, South Africa that is the site of ongoing HIV vaccine preparatory research. Recruitment for the study was through advertisements via the local community advisory board (CAB), churches, community groups and schools. Potential participants were eligible for the study if they were: 16-40 years of age; were HIV negative; were not pregnant; were residents in the community; and agreed to HIV testing and structured interviews over a 12-month period. Participants volunteered after testing HIV negative in the Voluntary Counselling and Testing service at the local public sector clinic.

Eligible individuals were provided with information about study procedures which was discussed with research staff before participants provided their written informed consent. After this, participants completed a structured, interviewer-administered questionnaire which included items on willingness to participate in vaccine research and general and HIV-related vaccine knowledge. Additional items on concerns about trial participation, and influences on decisions to participate in trials, were added after the start of research and are available only on a subset of participants (59%, n = 116). No remuneration was offered, and the study was approved by the Research Ethics Committee of the University of Cape Town.

Data were analysed using SPSS 11.0 (SPSS Corporation, USA). Responses to questions regarding general knowledge of vaccines and knowledge of HIV vaccines were combined into separate scales demonstrating good internal consistency reliability (Cronbach's alpha, 0.92 and 0.76, respectively), χ^sup 2^ and t-tests were used to detect bivariate associations, and multiple logistic regression was used to identify independent predictors of willingness to participate in HIV vaccine trials.

Table 1 Knowledge of vaccines, both generally and HIV-related, among 198 HIV-negative volunteers enrolled in a HIV vaccine preparedness study in a peri-urban South African township

Results

Between February and August 2003, 198 individuals were enrolled into the study. Most participants were women (80%, n = 158) and the mean age was 23 years. Almost all participants (98%, n = 193) had at least some secondary education.

General knowledge regarding vaccines was moderate, with 42% of participants (n = 93) answering more than half of the questions on this topic correctly (Table 1). However, levels of knowledge regarding HIV vaccines was substantially lower, with only three participants (2%) answering more than half of questions on this topic correctly. Increasing scores on the two scales were positively associated with increasing age (P < 0.001 for each), and general knowledge of vaccines was associated with male gender, though there were no associations involving educational level and either scale.

Overall 23% of participants (n = 46) stated that they would be willing to participate in HIV vaccine trials. In bi varia te analysis, willingness to participate in an HIV vaccine trial was associated with younger age (P < 0.001), increasing scores on both general and HIV vaccine knowledge scales (both P < 0.001), self- perception of HIV risk (P = 0.05) and male gender (P = 0.005). In a multivariate model adjusted for age, gender, and perceived HIV risk, the associations between scores on each vaccine knowledge scale and willingness to participate persisted. A 1-unit increase in the score for knowledge of vaccines generally was associated with almost a doubling in the relative odds of willingness to participate (adjusted odds ratio (OR), 1.91, 95% confidence intervals (CI): 1.25- 2.92), while a 1-unit increase in the scale for score for HIV vaccine knowledge was associated with a 10-fold increase in willingness to participate (adjusted OR, 10.72, 95% CI: 4.40- 26.12).

Table 2 Incentives to and concerns regarding participation in a hypothetical HIV vaccine trial, among HIV-negative volunteers enrolled in an HIV vaccine preparedness study in a peri-urban South African township

Table 2 shows the reporting of vaccine trialrelated incentives and concerns according to participants' willingness to participate in vaccine research. Both the possibility of being protected against HIV infection and altruism were cited as potential incentives by all participants, regardless of their willingness to participate. Meanwhile, the side-effects of HIV vaccines, as well as the possibility of testing positive on antibody tests if they received the vaccine, were the most commonly cited concerns among individuals regarding participation.

Discussion

These results provide valuable insights into willingness to participate in HIV trials research in this setting. Among individuals volunteering for HIVrelated research, less than one- quarter (23%) stated that they would be willing to participate in HIV vaccine trials. This finding contrasts with other studies from sub-Saharan Africa which report higher rates of willingness to participate in various populations,8'9 but is comparable to results from Thailand and the United States.10'11

Willingness to participate was strongly and persistently associated with knowledge of vaccines, both in general and HIV vaccines specifically. This finding suggests that although willingness to participate in vaccine research may be somewhat low in this population, it may be addressed through appropriate education campaigns. This evidence has significant implications for efforts to increase awareness of HIV vaccines, as there is no suggestion here that increased knowledge of HIV vaccines is linked with decrease willingness to participation. The potential topics for inclusion in future HIV vaccine-related educational campaigns in this setting are suggested by the perceived incentives and concerns cited by participants, with side-effects and positive antibody tests from a vaccine both being important considerations.

While these results point to the potential value of preparatory work before HIV vaccine research begins, there have been concerns about raising expectations regarding HIV vaccines in the communities where studies are to be conducted. In addition to the topics highlighted in these data, any educational campaign prom\oting awareness of HIV vaccines should emphasize the experimental nature of these vaccines, and avoid raising hopes for an imminent solution to the epidemic.

This study was conducted in a relatively small sample of participants who had already volunteered to be part of a longitudinal HIV-related research project. While these findings may not be generalizable to the entire community, this study population is likely to be representative of individuals interested in HIV vaccine research in this and similar populations in South Africa. In addition, the hypothetical decision to participate in an HIV vaccine trial may not necessarily translate into actual behaviour,12 but nevertheless stated willingness to participate is a valuable proxy that is commonly employed in research in this area.

In summary, this study suggests that while levels of willingness to participate in HIV vaccine research may be relatively low in this and similar communities, these may be improved through vaccine- related educational programmes. More generally, this study highlights the importance of HIV vaccine preparatory research and community education as part of trial preparations in resource-poor settings.

Acknowledgements: This research was funded by the South African AIDS Vaccine Initiative. The authors wish to thank the following persons for their assistance: Prudence Mthimunye, Noliswe Malashe, Ayanda Mhlambiso, Phumla Madliwa, Skolweni Zelanga, Lububalo Vellem and Patricia Mhlambiso. The research was also supported by the South African AIDS Vaccine Initiative (SAAVI).

References

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(Accepted 26 April 2005)

J Smit MA1'2, K Middelkoop MBChB2, L Myer PhD2'3, S seedat MBChB FCPsych(SA)1, L-G Bekker MBChB PhD2, D J Stein MBChB PhD1'4

1 MRC Unit for Anxiety and Stress Disorders, University of Stellenbosch; 2Desmond Tutu HIV Centre, University of Cape Town; 3Infectious Diseases Epidemiology Unit, School of Public Health & Family Medicine, 4Department of Psychiatry, University of Cape Town, Cape Town, South Africa

Correspondence to: J Smit

Email: (oalida.Smit@bch.nhs.uk, djs2@sun.ac.za

Copyright Royal Society of Medicine Press Ltd. Mar 2006

Source: International Journal of STD & AIDS

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