ArticleVaccine2013
Does participation in an HIV vaccine efficacy trial affect risk behaviour in South Africa?
Article in Vaccine, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
15 citing papers in PubMed, 3 syntheses or guidelines pooled it, 24 citations in OpenAlex.
- Descriptions of risks and benefits of HIV vaccine trials in low-and middle-income countries (LMICs): an integrative review.BMC medical ethics · 2025Pooled it
- Reported oral and anal sex among adolescents and adults reporting heterosexual sex in sub-Saharan Africa: a systematic review.Reproductive health · 2019Pooled it
- How common and frequent is heterosexual anal intercourse among South Africans? A systematic review and meta-analysis.Journal of the International AIDS Society · 2017Pooled it
- Impact of universal testing and treatment on sexual risk behaviour and herpes simplex virus type 2: a prespecified secondary outcomes analysis of the HPTN 071 (PopART) community-randomised trial.The lancet. HIV · 2022Trial
- Sexual Behaviours and Practices before and after Phase I/II HIV Vaccine Trial: A Qualitative Study among Volunteers in Dar es Salaam Tanzania.International journal of environmental research and public health · 2020Trial
- Recombinant adenovirus type 5 HIV gag/pol/nef vaccine in South Africa: unblinded, long-term follow-up of the phase 2b HVTN 503/Phambili study.The Lancet. Infectious diseases · 2014Trial
- A review of public health, social and ethical implications of voluntary medical male circumcision programs for HIV prevention in sub-Saharan Africa.International journal of impotence research · 2023Review
- Sexually transmitted infections amongst men who have sex with men (MSM) in South Africa.PLOS global public health · 2023Article
- Condom use and risk factors of inconsistent or low use of the condoms during heterosexual anal intercourse in sub-Saharan Africa: a scoping review.African health sciences · 2022Article
- Mobile Phone Questionnaires for Sexual Risk Data Collection Among Young Women in Soweto, South Africa.AIDS and behavior · 2018Article
- Complex immune correlates of protection in HIV-1 vaccine efficacy trials.Immunological reviews · 2017Review
- Development of an HIV vaccine attitudes scale to predict HIV vaccine acceptability among vulnerable populations: L.A. VOICES.Vaccine · 2014Article
- The HVTN503/Phambili HIV vaccine trial: a comparison of younger and older participants.International journal of STD & AIDS · 2014Article
- Potential future impact of a partially effective HIV vaccine in a southern African setting.PloS one · 2014Article
- HIV-1 vaccines: challenges and new perspectives.Human vaccines & immunotherapeutics · 2014Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 7 institutions in 2 countries.
Funding
Abstract
backgroundIncreased sexual risk behaviour in participants enrolled in HIV prevention trials has been a concern. The HVTN 503/Phambili study, a phase 2B study of the Merck Ad-5 multiclade HIV vaccine in South Africa, suspended enrollment and vaccinations following the results of the Step study. Participants were notified of their treatment allocation and continue to be followed. We investigated changes in risk behaviour over time and assessed the impact of study unblinding.
methods801 participants were enrolled. Risk behaviours were assessed with an interviewer-administered questionnaire at 6-month intervals. We assessed change from enrolment to the first 6-month assessment pre-unblinding and between enrolment and at least 6 months post-unblinding on all participants with comparable data. A one-time unblinding risk perception questionnaire was administered post-unblinding.
resultsA decrease in participants reporting unprotected sex was observed in both measured time periods for men and women, with no differences by treatment arm. At 6 months (pre-unblinding), 29.6% of men and 35.8% of women reported changing from unprotected to protected sex (p<0.0001 for each). Men (22%) were more likely than women (14%) to report behaviour change after unblinding (p=0.009). Post-enrolment, 142 (45%) of 313 previously uncircumcised men underwent medical circumcision. 663 participants completed the unblinding questionnaire. More vaccine (24.6%) as compared to placebo recipients (12.0%) agreed that they were more likely to get HIV than most people (p<0.0001), and attributed this to receiving the vaccine.
conclusionWe did not find evidence of risk compensation during this clinical trial. Some risk behaviour reductions including male circumcision were noted irrespective of treatment allocation.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.