Phase 1 Clinical Trial of HIV Vaccine Starts in Zimbabwe and South Africa

The IAVI Logo (image source)

A Phase 1 clinical trial for a promising HIV vaccine candidate has commenced in Zimbabwe and South Africa, marking a major step forward in the global fight against HIV/AIDS. The trial will evaluate immune responses in both HIV-negative individuals and people living with HIV. In a joint statement, the lead organizations—Mutala Trust, ReiThera Srl, the Ragon Institute of Mass General Brigham, MIT, and Harvard, and IAVI—announced that the first doses of the investigational vaccine, GRAdHIVNE1, have been administered. The vaccine was first given on July 28, 2025, at the Mutala Trust clinical trial site in Harare.

The Gorilla Adenovirus Vectored HIV Networked Epitopes Vaccine (GRAdHIVNE1) is designed to provoke strong CD8+ T cell responses, which are crucial for targeting and destroying HIV-infected cells. The candidate is being tested for its potential both as a preventive vaccine and as a component in therapeutic or curative HIV strategies. This first-in-human Phase 1 trial will enroll around 120 healthy adults aged 18–50, including 48 HIV-positive participants who are stable on antiretroviral therapy (ART). The trial aims to assess safety and immunogenicity—the ability of the vaccine to provoke an immune response. Participants will receive one or two doses of the vaccine or a placebo, and will be monitored for up to 19 months.

The clinical trial, officially designated as IAVI C114, is being sponsored by IAVI and funded by the Gates Foundation. Clinical trial sites include:

• Mutala Trust, Harare, Zimbabwe

• Desmond Tutu Health Foundation (DTHF), Cape Town, South Africa

• Africa Health Research Institute (AHRI), Durban, South Africa
  

Dr. Tariro Makadzange, Clinical Trial Lead at Mutala Trust, described the initiative as a landmark moment for African-led health innovation. “We are edging closer to an HIV vaccine, made possible by global collaboration, with clinical trials conducted in Africa, for Africa, and for the world,” she said. Dr. Vincent Muturi-Kioi, HIV Vaccines Product Development Team Lead at IAVI, echoed this optimism: “This trial represents the future of vaccine development, rooted in Africa, built through global partnerships, and designed for the communities most affected by HIV.”

The Ragon Institute contributed to the design of the vaccine’s immunogen, using data from elite controllers—individuals who naturally suppress the virus without treatment. Dr. Gaurav Gaiha, a principal investigator at the Ragon Institute and Harvard Medical School, emphasized the importance of translating insights from long-term studies into real-world vaccine trials in high-burden settings like Southern Africa. Dr. Stefano Colloca, CEO of ReiThera, highlighted the significance of the GRAd platform, noting its potential to provoke potent CD8+ T cell responses that may target the most vulnerable regions of HIV. The trial is expected to yield key insights into both preventive and therapeutic applications, setting the stage for future HIV vaccine candidates and interventions aimed at long-term viral control or eradication.