TweetBy Michael GwarisaFor decades, scientists have battled the elusive human immunodeficiency virus (HIV), whose ability to mutate and develop resistance has defeated one vaccine candidate after another Now, a groundbreaking clinical trial under way in Zimbabwe and South Africa aims to outsmart the virus by targeting its most vulnerable, unchanging parts.The investigational vaccine, known scientifically as the Gorilla Adenovirus Vectored HIV Networked Epitopes Vaccine (GRAdHIVNE1), is designed to hit HIV where it hurts most: regions critical to its structure and function, making it harder for the virus to escape through mutation.On July 28, 2025, researchers at the Mutala Trust Clinical Trial Site in Harare administered the first doses to volunteers, marking the beginning of IAVI C114, a Phase 1, first-in-human study The trial will enroll about 120 healthy adults aged 18 to 50, including 48 people living with HIV who are virally suppressed on antiretroviral therapy (ART).The idea is to find components of the virus that, if they change too much, they compromise the virus itself,” explained Professor Tariro Makadzange, the study’s lead researcher
“We’re targeting regions that are critical for the virus and ensuring they’re relevant to strains common in our part of the world.”Why HIV Vaccines Have Been So DifficultSince HIV was identified in the early 1980s, the quest for a vaccine has been one of the most pressing goals in global health Yet, despite more than three decades of trials, no licensed vaccine exists.The challenge lies in the virus’s biology HIV mutates at an exceptionally high rate, around 3 × 10⁻⁵ mutations per base per replication cycle, which works out to roughly 0.3 mutations for each genome in every cycle In the human body, the rate can climb to approximately 4.1 × 10⁻³ mutations per base per infected cell, one of the highest mutation rates ever observed in a biological entity
With up to 10 billion new viral particles produced in a single person each day, this results in millions to billions of new variants daily This constant genetic churn allows HIV to evade immune defenses and, in some cases, develop drug resistance.“To say it’s mutation-resistant is not something we would claim,” Dr Makadzange cautioned “But we’ve designed it to make it hard for the virus to become resistant to the targeted regions by focusing on parts of the virus it can’t easily change without harming itself.”Previous vaccine candidates have failed mainly because the immune responses they triggered could not keep up with HIV’s relentless shape-shifting.The Networked Epitope ApproachThe new vaccine builds on a concept developed by Professor Gaurav Gaiha at the Ragon Institute of Harvard, Massachusetts General Hospital, and MIT
The approach, called “networked epitopes,” identifies HIV regions whose structural and functional importance makes them difficult to alter without collapsing the viral network.Dr Makadzange used a social analogy: “In some of your social networks, there are key people who hold the group together If that person drops out, the network falls apart We’re looking for those ‘key people’ in the virus.”The vaccine’s design also considers genetic and environmental differences that shape immune responses
The immune system of someone in Zimbabwe might process a pathogen differently from someone in Europe, underscoring the importance of testing vaccines in diverse populations.How the Vaccine WorksThe GRAdHIVNE1 vaccine uses a gorilla adenovirus vector, a harmless cold virus engineered to deliver HIV’s networked epitopes to the immune system Adenoviruses from humans, chimpanzees, and gorillas have been used in other vaccines, including those for COVID-19 and Ebola.This gorilla adenovirus vector was developed by ReiThera Srl, an Italian biotechnology company The vector serves as a delivery vehicle, carrying genetic instructions that train the immune system to recognize and attack the targeted regions of HIV.The aim is to induce strong T-cell responses – immune cells capable of killing infected cells and controlling the virus even if infection occurs.Trial Design and ParticipantsThe IAVI C114 trial will take place at three sites: the Mutala Trust Clinical Trial Site in Harare, the Desmond Tutu Health Foundation in Cape Town, and the Africa Health Research Institute in Durban Participants will receive either one or two doses of the investigational vaccine or a placebo
They will be followed for 19 months to assess safety and the strength of immune responses “We are also including people living with HIV, which is unique and exciting,” Dr Makadzange said “This lets us explore therapeutic vaccines – boosting immune responses in people already infected to better control the virus.” Pregnant Women Not Included Yet Although pregnant women are a key population for HIV prevention, they are not part of this early-stage trial.“At this stage, we’re focusing on two things: is the vaccine safe, and does it generate an immune response?” Dr
Makadzange explained “Later, as evidence grows, we can include other groups like pregnant women.”African Leadership in Global ScienceOne of the trial’s most significant aspects is that it is led from Africa Mutala Trust was established in 2021 to address a long-standing gap: although Africa is home to nearly 20 percent of the world’s population, only 2 to 3 percent of global clinical trials are conducted here.“If we’re not part of research, we can’t be sure medicines and vaccines work as well in us as in the populations where they were tested,” said Prof Makadzange
“We also lose the chance to develop the scientific capacity we need to solve our own health problems.”The trial’s laboratory work will also remain on the continent, with samples processed at state-of-the-art African facilities, including the Cape Town HVTN Immunology Laboratory, the African Health Research Institute in Durban, and the National Institute for Communicable Diseases in Johannesburg This model ensures skills, infrastructure, and knowledge stay within African research institutions.Zimbabwe has an estimated 12 percent HIV prevalence, among the highest in the world The epidemic has touched nearly every family, either directly or through friends and relatives While antiretroviral therapy has transformed HIV from a death sentence into a manageable chronic condition, the need for a preventive vaccine remains urgent.Not the First, But Possibly DifferentThis is not the first attempt at an HIV vaccine, but unlike earlier designs, this one was built with the virus strains circulating in southern Africa in mind, particularly clade C, which is dominant in the region.“We’re not saying this is the vaccine that will solve HIV,” Prof
Makadzange emphasized “But the science is promising, and even if it doesn’t succeed, it will help us learn how to make the next vaccine better – for our populations, based on our genetics and immune responses.”Global and Local CollaborationThe trial is sponsored by IAVI and funded by the Bill & Melinda Gates Foundation ReiThera developed the gorilla adenovirus vector and manufactured the vaccine The Ragon Institute designed the immunogen using novel epitope-targeting strategies
African principal investigators are steering the clinical work, ensuring the research is grounded in the realities of the communities most affected.The Long Road AheadEven if early results are promising, a licensed HIV vaccine is still years away Phase 1 trials like IAVI C114 primarily assess safety and the ability to provoke an immune response Larger Phase 2 and Phase 3 trials, which test effectiveness in preventing infection, would follow if results warrant.But the stakes are too high not to try As Dr
Makadzange put it: “HIV is not an easy problem to solve But bringing this research to Africa from the start ensures the solutions are made for us, by us.”
Source: HealthTimes
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Source: HealthTimes
Source: Healthtimes
