Abstract:

Misinformation suppresses demand for many biomedical services, including emerging HIV prevention technologies. We tested whether psychological inoculation – brief prebunking messages that present and refute persuasive, misleading claims and tactics – can protect intentions to accept a future HIV vaccine. In an online randomised controlled trial (July-October 2025), 2,163 young women in South Africa were assigned to view either two short inoculation videos or attention-matched control videos. Participants were subsequently shown multiple misinformation claims, and outcomes were measured immediately and at a three-week follow-up. Inoculation videos prevented the decline in HIV vaccine intentions observed in the control group and increased willingness to recommend the vaccine to others. The intervention also substantially reduced perceived credibility, emotional impact, and shareability of misinformation, with effects extending to new claims not presented in the videos, and persisting over three weeks. Brief, scalable prebunking messages may help ensure public confidence in new HIV prevention technologies.

About the presenter:

Dr Brendan Maughan-Brown (PhD) is an interdisciplinary social scientist with expertise on the uptake of HIV-prevention and treatment services; behavioural economics; the social and behavioural determinants of HIV risk; and survey design. Dr Maughan-Brown serves as a Chief Research Officer at SALDRU, University of Cape Town. He is a faculty member at Indlela – a behavioural nudge unit based at the University of the Witwatersrand's Health Economics and Epidemiology Research Office (HE2RO). Brendan's primary research interests include the design and evaluation of behavioural interventions to increase demand for health services and products, including interventions to help people living with HIV to access care and treatment; and understanding high HIV incidence rates among young women in Africa.