The first doses of an investigational HIV vaccine candidate have been administered in Africa, marking a significant milestone in HIV prevention research. The Gorilla Adenovirus Vectored HIV Networked Epitopes Vaccine (GRAdHIVNE1) was first administered on July 28, 2025, at the Mutala Trust clinical trial site in Harare, Zimbabwe, as part of a global collaboration led by African researchers.
Novel Vector Platform Addresses Key Challenges
The vaccine candidate utilizes ReiThera's proprietary gorilla adenovirus (GRAd) vector platform for delivery of HIV antigens. Unlike human adenoviral vectors, GRAd encounters minimal pre-existing immunity in humans, which can otherwise reduce the efficacy of gene-based therapies. This technological advantage could potentially improve the vaccine's effectiveness in target populations.
The immunogen design from the Ragon Institute is specifically engineered to combat the HIV virus's rapid mutation and immune evasion by focusing on highly conserved HIV epitopes—stable regions less susceptible to mutation—potentially enabling long-lasting protective immunity.
Phase 1 Trial Design and Scope
This Phase 1, first-in-human clinical trial will enroll approximately 120 healthy adults aged 18-50 years, including 48 people living with HIV who are virally suppressed on antiretroviral therapy (ART). The trial is designed to assess the safety and immunogenicity of the vaccine candidate in people living with and without HIV.
Participants will receive either one or two doses of the investigational vaccine or a placebo and will be monitored over a period of 19 months for safety and immune responses. The clinical trial, designated IAVI C114, is sponsored by IAVI and funded by the Gates Foundation.
African-Led Research Initiative
The trial is taking place at three clinical trial sites across Africa: the Mutala Trust Clinical Trial Site in Harare, Zimbabwe; the Desmond Tutu Health Foundation (DTHF) in Cape Town, South Africa; and the Africa Health Research Institute (AHRI) in Durban, South Africa. To determine the vaccine candidate's potential for relevance in sub-Saharan Africa, where disease burden is greatest, it is essential that the candidate be tested within communities affected by the epidemic.
Vaccine immunogenicity will be assessed locally by a network of state-of-the-art African research institutes: Cape Town HVTN Immunology Laboratory in Cape Town, African Health Research Institute in Durban, and the National Institute for Communicable Diseases in Johannesburg, South Africa.
Collaborative Development Effort
GRAdHIVNE1 has been made possible by a collaborative effort between multiple organizations. ReiThera developed the GRAd viral vector platform and manufactured the vaccine candidate, while the Ragon Institute designed the immunogen using novel strategies to identify protective HIV epitopes and facilitate their targeting by T cells. ReiThera provides both the GRAd vector technology and GMP-compliant manufacturing for this study.
The effort represents a partnership between The Mutala Trust, ReiThera Srl, the Ragon Institute of Mass General Brigham, MIT, and Harvard, and IAVI, with a team of African principal investigators leading the clinical research in South Africa and Zimbabwe.
