A new investigational HIV vaccine candidate, GRAdHIVNE1, has entered Phase 1 clinical trials in Zimbabwe and South Africa. The vaccine is designed to prompt strong immune responses targeting vulnerable regions of the virus using a T cell-inducing vector.

The first doses were administered on July 28, 2025, at the Mutala Trust clinical trial site in Harare, Zimbabwe. The trial, known as IAVI C114, is enrolling approximately 120 healthy adults aged 18–50, including 48 people living with HIV who are virally suppressed on antiretroviral therapy. The aim is to assess both safety and immunogenicity over a 19-month period.

The study is led by African principal investigators and supported by a collaboration involving the Mutala Trust, ReiThera, the Ragon Institute of Mass General Brigham, MIT and Harvard, and IAVI. Immunogenicity assessments will be conducted at leading African research institutions including the Cape Town HVTN Immunology Laboratory, the African Health Research Institute in Durban, and the National Institute for Communicable Diseases in Johannesburg.

The vaccine candidate, developed on the GRAd (gorilla adenovirus) platform, was designed to induce potent CD8+ T cell responses targeting critical structural regions of HIV. ReiThera created the vector and manufactured the vaccine, while the Ragon Institute designed the immunogen based on studies of elite HIV controllers—individuals who naturally suppress the virus without therapy. The trial is funded by the Gates Foundation.

Clinical trial sites include:

• Mutala Trust Clinical Trial Site, Harare, Zimbabwe

• Desmond Tutu Health Foundation, Cape Town, South Africa

• Africa Health Research Institute, Durban, South Africa

“This is a landmark moment for South Africa, Zimbabwe, and the continent. It shows the power of true partnership: IAVI’s sponsorship, ReiThera’s GRAd technology, the Ragon Institute’s innovative immunogen built on decades of science, and African investigators co-leading every phase of the trial. 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,” said Dr Tariro Makadzange, clinical trial lead at the Mutala Trust.

“This trial represents the future of vaccine development, rooted in Africa, built through global partnerships, and designed for the communities most affected by HIV,” added Dr Vincent Muturi-Kioi, HIV vaccines product development team lead at IAVI.

Dr Gaurav Gaiha, associate professor of medicine at Harvard Medical School and principal investigator at the Ragon Institute, said, “We are thrilled to be moving insights from our long-term studies of spontaneous elite controllers of HIV toward the development of GRAdHIVNE1 and its testing in Africa. We are truly grateful to the network of global and African partners that have come together to make the IAVI C114 trial a reality.”

Because CD8+ T cells play a key role in targeting HIV-infected cells, this trial will also assess the vaccine’s potential for use in future therapeutic or curative strategies.

“We are enormously pleased with the launch of this Phase 1 trial representing the result of a successful global partnership,” said Stefano Colloca, CEO and co-founder of ReiThera. “This candidate HIV vaccine, built on our GRAd platform, holds great promise to trigger a strong CD8 response targeting vulnerable viral regions.”