It’s a familiar scene, isn’t it? You’re scrolling through your social media feed, and there it is – a post that makes you do a double-take, wondering if what you’re reading could possibly be true. Often, these posts revolve around health, a topic ripe for misinformation. Perhaps it’s a heartfelt story about someone falling ill after a vaccine, or a sensational claim that a life-saving medication actually causes the very illness it’s meant to prevent. These messages, shared countless times by well-meaning but frightened or confused individuals, paint a picture of a world where crucial health information is constantly battling against a tide of uncertainty. This is the complex landscape into which a revolutionary HIV prevention drug, lenacapavir (LEN), is being introduced. Imagine a treatment that, with just two injections a year, could virtually eliminate the risk of contracting HIV – it’s truly an extraordinary scientific leap. Yet, the sheer excitement surrounding this pre-exposure prophylaxis (PrEP) product, which promises to halt the virus in its tracks, means little if people aren’t willing to take it. As someone who has spent years studying health behavior, I know that even the most effective and accessible health products face an uphill battle in terms of adoption. The chasm between what a product can do and what communities actually do with it is often where the fight against epidemics is lost, and misinformation is a major culprit in widening this gap.
My colleagues, Alison Buttenheim, Harsha Thirumurthy, and I recently collaborated with Indlela, the behavioral science unit at Wits University’s Health Economics & Epidemiology Research Office (HE²RO), on research that offers a promising way to tackle this challenge: getting ahead of social media misinformation about LEN. Our findings, published earlier this year in BMJ Global Health, reveal a concerning trend. We mapped out the emerging concerns and false claims already circulating even about a future HIV vaccine, and the patterns were striking. We found recurring themes: that HIV prevention tools are designed to harm specific populations, that they cause the very conditions they’re designed to prevent, and that their side effects are catastrophic and deliberately hidden. To understand which of these claims would most deter young women from taking HIV prevention products, we conducted an online survey with 188 young South African women, asking them to rate 54 different misinformation claims. What we discovered was quite surprising. We had anticipated that fears of being infected with HIV by a vaccine or elaborate conspiracy theories, like claims of foreign governments sterilizing Black women, would be most prominent. Instead, what topped the list were fears of catastrophic, terminal physical harm: beliefs that the product “will kill you,” alongside claims of liver, kidney, and heart failure, bone marrow damage, and cancer. It seems that vivid, frightening claims have a way of embedding themselves in our memory, and once there, a later rebuttal struggles to dislodge them.
These findings resonate with a broader pattern we’ve observed in this age of vaccine hesitancy, which was significantly amplified during the COVID-19 pandemic. Safety fears were a primary reason for COVID-19 vaccine refusal; in South Africa, for instance, nearly 40% of those most resistant to the COVID vaccine believed it could be fatal. This belief isn’t always rooted in malice; rather, it’s partly a byproduct of scale. When tens of millions of people are vaccinated in a short period, it’s statistically inevitable that some deaths, completely unrelated to the vaccine, will occur shortly afterward. These coincidental events transform into stories, which then become posts, and these posts are seen and shared, spreading like wildfire. Imagine a young woman hearing such a story from a friend or her aunt – it’s incredibly hard to unhear. Once misinformation takes root, it’s notoriously difficult to uproot, even with repeated debunking. This is simply how our human brains are wired; we process emotionally charged stories far more powerfully than rational corrections. A vivid, frightening claim sticks in the mind in a way that dry, factual rebuttals almost never can. LEN, unfortunately, has certain characteristics that make it particularly susceptible to this kind of misinformation. One of the biggest concerns for researchers like myself is that people will inadvertently mistake LEN for a vaccine. After all, it’s an injection taken to prevent a disease, so isn’t it a vaccine? However, LEN is a PrEP product, and its mechanism of action is fundamentally different from a vaccine. A vaccine trains your immune system to produce antibodies to fight off a disease, whereas PrEP works by blocking HIV from entering your cells and is effective only as long as it’s taken. This distinction is crucial, as existing misinformation about vaccines in general could easily be layered onto new misinformation about LEN, creating a dangerous cocktail of compounded false beliefs.
Adding to LEN’s vulnerability is another specific feature: the injection can cause a visible nodule or bump under the skin. Most drug side effects are internal and invisible – a headache, some nausea. But a visible lump? That can be photographed. I am genuinely concerned about the impact when images of these nodules begin circulating online. Just imagine the captions, the unfounded implications, and the scaremongering that will inevitably emerge, completely divorced from clinical reality. Misinformation often needs just a “grain of truth” to latch onto, and a visible lump under the skin is almost a perfect hook. Recognizing this challenge, our team explored an approach called psychological inoculation, or “pre-bunking,” designed to make people less vulnerable to misinformation. We initially tested this approach with HIV vaccine misinformation. The timing was ideal because an HIV vaccine doesn’t yet exist, so misinformation about it was emerging but hadn’t yet become deeply entrenched in public consciousness.
The concept of psychological inoculation mirrors medical vaccination. You expose people to a weakened “dose” of misinformation – perhaps through humor that discredits the false claim – alongside a clear explanation of the manipulative strategies used to sway attitudes, beliefs, and behaviors. This is all done before they encounter the misinformation in the real world. The goal is to build “cognitive antibodies” – mental tools that help individuals recognize and counter false information. We developed 2½-minute TikTok-style videos that presented common false claims and then explained why those claims were untrue. Working with the production company Reel Epics, we co-created these videos through workshops with young women from an HIV service delivery organization. They provided invaluable feedback, bluntly telling us that our initial scripts needed to be “de-Harvardised,” stripped of academic jargon if anyone was going to watch them past the first five seconds. In a trial with over 2,000 young South African women aged 18 to 29 (a study currently under review for publication), we saw remarkable results. Participants who watched our pre-bunking videos actually increased their intentions to accept a future HIV vaccine even after seeing misinformation. In contrast, among those who didn’t see the pre-bunking videos and only encountered the misinformation, their intentions were 13% lower. Crucially, participants who viewed the pre-bunking videos were also less likely to say they would share misinformation if they encountered it on social media. The videos not only reduced the credibility of the specific claims they targeted but also had a broader effect, reducing the perceived credibility of other misinformation claims. Even three weeks later, the group that watched the pre-bunking videos maintained higher intentions for getting an HIV vaccine compared to those who hadn’t seen them. Significantly, these videos proved most effective among participants who had not received the COVID-19 vaccine – essentially, those already most hesitant about vaccination. This is precisely the group most susceptible to misinformation and, therefore, the group most in need of support to ensure their decisions about LEN are not swayed by false or misleading information.
Based on these compelling results, we’ve already adapted the videos for LEN, using the same format and the same persuasion technique framework. These videos are now being shared on social media platforms by organizations promoting LEN and are freely available for anyone to use. We are also in the early stages of a new study, specifically focused on LEN misinformation, to expand our findings to a more diverse socioeconomic sample. While two short, well-designed videos can’t single-handedly solve a misinformation crisis, they represent a powerful starting point. Scaling this type of intervention to reach the women who most urgently need LEN – those in communities where health conspiracy theories are deeply rooted, those less connected to digital platforms, and those whose decisions are heavily influenced by their immediate social networks – will require significant investment and coordinated effort. Government health departments, NGO partners, and community health workers all have crucial roles to play. They must all recognize the urgency of acting now to confront the threat of misinformation before it goes viral and becomes deeply entrenched. I truly believe that misinformation is one of the greatest threats to public health we will face in the coming decade. It doesn’t patiently wait for a product to launch; it thrives in the gap between excitement and access, between announcement and actual uptake. The window for pre-bunking – for embedding these cognitive antibodies before false claims become widely accepted – is open right now, and we must seize this crucial opportunity.