A mid-stage clinical trial being conducted by Johnson & Johnson over its HIV vaccine in southern Africa has been halted over findings that the vaccine's effectiveness to protect patients against the lethal infection was insufficient.
Paul Stoffels, J&J's Chief Scientific Officer, said the Imbokodo trial has revealed that the vaccine was only 25% effective in preventing HIV infection during two years, falling short of the aim of 50% efficiency, according to a release.
In final-stage research named Mosaico, an equivalent vaccine created by the pharmaceutical company will be tested in Europe and the Americas.
The study's suspension is yet another setback in the fight against HIV, a preventable but potentially fatal disease that affects about 38 million people worldwide.
Last year, around 1.5 million people were infected by HIV. While humans can live healthy lives despite being infected with the virus, vaccination protection remains out of reach.
Stoffels commented that it appears to be quite difficult to do so using vaccines. The virus quickly integrates into the body, making immune response extremely difficult to build.
Imbokodo trial began enrolling participants in 2017, with an emphasis on HIV-positive women. About 2,600 women were involved in the trial, which took place in five nations in the southern part of the continent, where HIV infection is relatively common and typically spreads through heterosexual contact.
Mitchell Warren, Executive Director of AVAC, an HIV vaccine advocacy organization, said that protecting women from HIV infection is still a major issue worldwide. It's disappointing to learn that this product will not be a practical option for women at risk."
Warren praised J&J's efforts on an HIV vaccine, noting that it is the first major pharmaceutical company to make significant progress since Merck & Co.'s failed trial of a promising vaccine about 15 years ago. He also highlighted J&J's adenovirus-based technology's success in the Ebola and Covid vaccines.