Research Roundup: Ebola vaccine candidate, Lassa virus test, Gonorrhea antibiotic approval

Few diseases have shaped global health like the HIV/AIDS pandemic. Since it began, more than 40 million lives have been lost, leaving an enduring impact on families, communities, and health systems worldwide. But HIV has also become one of the clearest examples of what sustained research and development (R&D) can achieve. From antiretroviral therapies (ART) to long-acting prevention tools, decades of scientific innovation have fundamentally changed what is possible in the fight against HIV.This year, HIV innovation stands at a pivotal moment. Shifting funding landscapes and evolving global health priorities have raised important questions about how R&D for HIV will be sustained in the years ahead. As global leaders have reaffirmed the importance of continued R&D investment—such as through the recently adopted United Nations High Level Meeting political declaration on HIV/AIDS—we must also focus on the systems and programs that translate scientific breakthroughs into impact. Few advances better illustrate this balance than lenacapavir, or LEN, an injectable form of HIV prevention requiring only two injections per year, spaced 6 months apart. Unlike daily oral pre-exposure prophylaxis (PrEP), which depends on consistent adherence, LEN offers protection by eliminating daily pill burden for consumers and communities vulnerable to HIV.The journey of LEN reflects the long arc of HIV innovation. Decades of research supported by the US National Institutes of Health helped establish the HIV capsid as a promising drug target, creating the foundation for a new class of HIV medicines. Then, in 2006, researchers at Gilead Sciences began developing capsid inhibitors designed to suppress HIV replication while offering the potential for long-acting treatment. At the time, ART had transformed HIV from a fatal disease into a manageable chronic condition for millions of people, but treatment relied on daily medication, creating ongoing challenges for adherence and access.Following years of research and clinical development, the US Food and Drug Administration (FDA) approved LEN in 2022 as a treatment for adults living with multidrug-resistant HIV whose existing treatment regimens were no longer effective. While this approval marked an important milestone, researchers at Gilead continued exploring the drug's potential as a long-acting option for HIV prevention and found remarkable resultsThe first pivotal late-stage prevention trial of the drug, called PURPOSE 1, conducted among women in South Africa and Uganda—including pregnant and lactating women—found that LEN provided near-complete protection against HIV infection and outperformed daily oral PrEP. PURPOSE 2, a subsequent study, conducted across seven countries and including men and gender-diverse people, confirmed similarly high levels of protection in late 2024. Beyond their clinical success, these studies also represented an important step toward more inclusive HIV research by intentionally enrolling populations that have been historically underrepresented in clinical trials.  Just six months after Gilead submitted LEN for review as an HIV prevention tool, the FDA approved the drug in June 2025 under a priority review designation pathway. Because regulators were able to rely on the extensive safety data generated during the drug's earlier approval for HIV treatment, they could focus their review on its use as a novel preventive intervention. The result was an efficient regulatory process that maintained rigorous standards while accelerating future access to an important new prevention tool. Swift regulatory action extended beyond the United States. In October 2025, the World Health Organization (WHO) prequalified LEN in just 36 days using its abridged prequalification pathway. This expedited process enabled WHO to leverage assessments already completed by the European Medicines Agency’s (EMA) European Union-Medicines for all program, which provides scientific opinions on medicines for use in low- and middle-income countries, while conducting its own review focused on issues relevant to the global procurement and implementation of LEN.  This rapid review mattered because WHO prequalification serves as a critical gateway for procurement by many international organizations and countries, particularly in low- and middle-income countries. Accelerating this process helps ensure that countries are not waiting months or years for access after a product has already demonstrated its safety and effectiveness through other rigorous stringent regulatory approval processes.Accelerated regulatory approval and collaboration continued across multiple regions. Following FDA, EMA, and WHO approval, LEN rapidly advanced through regulatory processes in South Africa, Australia, Brazil, and Canada, and, as of today, it is approved by 17 regulatory bodies, including 12 countries in Africa. In several cases, regulators leveraged reliance mechanisms, such as WHO’s collaborative registration procedure, international collaboration, and priority review pathways to streamline review and accelerate access to this important breakthrough without compromising regulatory rigor. Swift regulatory action was soon matched by commitments from the United States; the Global Fund to Fight AIDS, Tuberculosis and Malaria; and Gilead to rapidly scale up access to LEN and accelerate generic production in high-burden countries.This coordinated approach, supported by political commitment and strategic public-private partnership, created an unusually efficient pathway from scientific discovery to implementation. Compared with earlier HIV prevention technologies, such as oral PrEP and the dapivirine vaginal ring, LEN has progressed through key milestones at a rapid pace. This allowed for accelerated product introduction of lifesaving technologies at the country level, while simultaneously shaping the market and demand for LEN and future prevention options. While every health technology faces unique scientific, regulatory, and access considerations, LEN demonstrates how thoughtful planning, regulatory preparedness, and collaboration between researchers, regulators, countries, multilateral organizations, and communities can significantly shorten the time between discovery and access.As conversations about the future of HIV innovation continue, LEN offers an important blueprint for global health innovation more broadly. It reminds us that sustained investment in R&D produces transformative breakthroughs, inclusive clinical trials generate stronger science, and innovative regulatory pathways can accelerate, rather than compromise, rigorous review. Moreover, the accelerated path from research to rollout illustrates the coordination and collaboration required to advance technologies through regulatory approval while simultaneously shaping markets to enable introduction at scale. The lessons from LEN are already informing the next generation of HIV prevention innovations, with developers pursuing earlier access and licensing strategies for products such as Merck's MK-8527. While the US government, the Global Fund, and Gilead have recently expanded commitments to scale up LEN, the ultimate measure of success will be whether LEN—and the innovations that follow it—reach the people who need them most.  The future of innovations for HIV, as well as tuberculosis, malaria, emerging threats with pandemic potential, and beyond, will require the same integrated approach. Scientific discovery, product development, efficient regulatory pathways, and equitable access cannot be treated as separate objectives; they are mutually reinforcing components. Innovation succeeds not when a product is approved, but when it reaches the communities whose lives it has the power to change. LEN has shown us what’s possible when the entire R&D ecosystem works together. The challenge now is ensuring that this success becomes the standard rather than the exception.

Interim study findings that will be presented at this week’s AIDS 2026 conference show that a new, once-weekly antiretroviral combination pill for HIV seems to be effective and well tolerated, with comparable results to currently available daily pills. The findings are from two ongoing large, multi-country Phase 3 trials comparing the new combination pill to current treatment options. The new combination treatment has the potential to greatly simplify HIV treatment for patients and health care providers by reducing treatment frequency—and potentially cost—which could help improve access and adherence. A new study in humans suggests that Merck’s Ervebo vaccine, which is licensed for the Zaire strain of ebolavirus, could offer some protection against the Bundibugyo strain of ebolavirus, fueling a growing number of calls to evaluate Ervebo in a clinical trial in the Democratic Republic of the Congo (DRC), the site of the rapidly expanding outbreak of Bundibugyo, for which there are no licensed vaccines. The World Health Organization has so far prioritized evaluation of Bundibugyo-specific vaccines, but the few in development are still months away from clinical trials in the DRC. A trial of Ervebo could provide some protection to people at risk in the outbreak sooner, since there is an international stockpile of Ervebo doses. The Africa Centres for Disease Control and Prevention is planning a trial that would test a two-dose vaccine regimen of Ervebo and an experimental vaccine targeting Sudan Ebola in health workers. Last week, IAVI and Biofabri announced that their Phase 2b clinical trial of tuberculosis (TB) vaccine candidate MTBVAC has reached full enrollment. The trial is evaluating the safety and efficacy of MTBVAC in preventing active TB disease in adolescents and adults with latent TB infection, as well as an additional cohort of participants who have never been exposed to TB infection, across 16 clinical research centers in South Africa, Kenya, and Tanzania. The current TB vaccine is more than 100 years old and provides incomplete protection in young children and does not prevent TB disease in adolescents and adults. MTBVAC, which is single-dose and well-suited for use in remote locations, could be a game-changer for TB control.