The hope for a viable HIV vaccine gained new ground with a study launched in Africa by Janssen Pharmaceutical Companies with support from the National Institutes of Health and the Bill and Melinda Gates Foundation.
The first efficacy study for an investigational mosaic HIV-1 preventive vaccine, the trial (HVTN 705/HPX2008) will evaluate whether a potential two-vaccine regimen is safe and able to prevent HIV. Scientific American reports that the “mosaic technology” combines “immune-stimulating proteins from different HIV strains, representing different types of viruses from around the world.”
“Our investigational vaccine is based on mosaic antigens that have been engineered using genes from a wide range of different HIV subtypes,” reiterated Dr. Johan Van Hoof, managing director at Janssen Vaccines and Prevention, in a statement to the press. “The ultimate goal is to deliver a ‘global vaccine’ that could be deployed in any geographic region to help protect vulnerable populations at risk of infection.”
The vaccine trial is also known as “Imbokodo,” the Zulu word for the stones traditionally used for grinding grain — and short-hand for a well-known proverb in South Africa: “Wathinta abafazi, wathinta imbokodo,” (which roughly translates to: “You strike the woman, you strike the rock,” but also incorporates the notion that women play a central role in the survival of their families). According to a Johnson & Johnson press release, the choice of the term pays homage “to the strength of women and their importance in the community.”
Avert, an organization fighting the global HIV epidemic, reports that as of 2015 an average of 4,500 new HIV transmissions occur among young women in east and southern Africa every week, which is “double the number in young men.” Furthermore, the organization notes, in west and central Africa, 64 percent of new HIV infections among young people in 2015 were among women.
It is these disturbing numbers that have researchers focusing their vaccine trials on women. The Janssen trial hopes to recruit 2,600 sexually active women aged 18 to 35 in five sub-Saharan African countries. Another vaccine trial (HPTN 077), by ViiV Healthcare, is already underway, enrolling 3,200 women in the region to evaluate using a long-acting injectable version of cabotegravir as a vaccine, according to NAM’s AIDSMap.
Janssen’s own proof-of-concept efficacy study follows two earlier clinical trials, including the ongoing TRAVERSE study, which compares two regimens containing adenovirus 26 (Ad26) vectored vaccines. Plus previously reported that Ad26 (a vaccine that has parts of HIV in it to spur the immune system to fight the virus) was shown effective in suppressing viral loads in HIV-positive monkeys — even after treatment was discontinued. It could therefore also eventually lead to a functional cure for HIV.
In this vaccine study, Ad26 will be combined with a protein, Clade C gp140, which, according to the study’s site, Imbokodo.org.za, is similar to a protein found on the surface of HIV, and also helps humans develop an immune response to the virus. In addition, the protein will be mixed with the booster aluminum phosphate (which is also used in vaccines for hepatitis A and tetanus).
Results could take up to four years, researchers cautioned on the site. Still, as Johnson & Johnson’s press materials point out, for the first time in over a decade, two vaccine trials are ongoing at the same time. Both are raising new hope for long-acting HIV prevention for women and men in Africa
“Developing a vaccine against HIV is a top priority and our best hope for a world without AIDS,” noted Dr. Paul Stoffels, chief scientific officer at Johnson & Johnson, in a company press release. “Finding an effective HIV vaccine to protect people at risk has been a major scientific challenge, but today there is new optimism that we can get there.”