NAIROBI, Kenya, Sept 5 – The Johnson & Johnson HIV vaccine trial has been stopped in South Africa (SA) after it failed to show its viability to protect people from contracting the virus.
The trial dubbed, “Imbokodo”, which kicked off its trials in 2017 and involved 2,600 women at high risk of infection in SA and four neighbouring countries, showed that the vaccine was just 25 pc effective in the prevention of HIV, short of a 50 pc goal in efficacy.
“We have to fundamentally re-look at what we’re doing,” said Glenda Gray, who heads the South African Medical Research Council and oversaw the protocol for the trial, which compared the efficacy of the vaccine to a placebo.
J&J’s chief scientific officer, Paul Stoffels, meanwhile stated that despite the failure, a second efficacy trial of a similar vaccine in a different study population will continue.
The “Mosaico” trial, which is taking place in the Americas and Europe and started in 2019, involves 3800 transgender people and men who have sex with men.
“We are currently evaluating the ability of an improved version of the “Mosaico” vaccine to protect against transmission through the rectal, rather that the vaginal route,” said Stoffels.
Both Imbokodo and Mosaico combine a total of four doses of two different shots. The first uses the same backbone as J&J’s COVID-19 product: adenovirus 26, a harmless “vector” that, in this case, shuttles four HIV genes into human cells.
The different HIV genes were engineered to produce HIV proteins that provoke an immune response broad enough to protect against a wide range of virus strains.
The second shot consists of a genetically engineered version of HIV’s surface protein, although the exact protein differs between the two studies.
Several research groups have begun human trials of vaccines designed to spur potent neutralizing antibodies against HIV, but none will likely enter full-scale efficacy trials for about 4 years, Lawrence Corey, a vaccine researcher at the Fred Hutchinson Cancer Research Center said.
“We have our work cut out for us,” he adds. “Maybe COVID vaccines will give us a lesson about how to speed this up.”
The study was launched in 2017 by J&J working with the US National Institute of Health and the Bill and Melinda Gates Foundation..
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