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A new vaccine against Human Immunodeficiency Virus (HIV), being tested in humans, is expected to end nearly 40 years of research for a measure effective prevention against infection, according to a new study.
In the first phase, the vaccine was tested in monkeys and humans. The clinical trial involving nearly 400 uninfected healthy adults has shown the production of an anti-HIV immune mechanism. In monkeys, the vaccine protected 67% of them from infection.
The vaccine efficacy trial progressed to the next level; About 2,600 women in southern Africa at risk of contracting HIV are tested to determine the safety and effectiveness of the candidate vaccine.
Scientists named the test phase as HVTN705 or "Imbokodo".
Previously, the development of the HIV vaccine focused on specific regions of the world. The study published in The Lancet takes different strains of the HIV virus and combines them to trigger immune responses against a wide variety of variations in HIV. The experimental regimens tested in this study are based on "mosaic" vaccines, the researchers maintained.
"These results represent an important step: this study demonstrates that the Ad26 Prime mosaic, Ad26 plus gp140, stimulates robust immune responses in humans and monkeys," says Professor Dan Barouch, Director of the Center for Virology and Research. on the vaccines that led the study.
HIV vaccine trials for efficacy progressed after 35 years
Since the global outburst of the HIV / AIDS epidemic in the 1980s, only four vaccines have been tested in humans.
In 2003, an HIV vaccine trial VR144 in Thailand reduced the rate of human infection by 31%. However, "the effect was considered too weak to advance the vaccine for common use," the researchers said.
The new vaccine, according to the researchers, "is one of five experimental designs of HIV vaccines that have progressed to efficacy trials in humans over the 35 years of the disease. global epidemic of HIV / AIDS ".
At present, more than 37 million people are living with HIV / AIDS. Alarmingly, nearly 1.8 million new cases are reported each year.
The scientific community has been trying for decades to develop an HIV vaccine with robust efficacy. One of the main challenges for the development of HIV vaccines has been the lack of direct comparability between clinical trials and preclinical studies.
Barouch led a team in 2015 to address the barriers, evaluating the main candidate mosaic vaccines in parallel clinical and pre-clinical studies. The study aimed to identify the optimal pattern of HIV vaccine to advance in clinical trials of effectiveness.
"The challenges in the development of an HIV vaccine are unprecedented, and the ability to induce specific immune responses to HIV does not necessarily indicate that a vaccine will protect humans against HIV infection. "
The trial recruited 393 healthy participants from East Africa, South Africa, Thailand and the United States. -United. They were randomly badigned to receive one of seven vaccine combinations or a placebo and received four vaccinations within 48 weeks.
To "boost" the level of the body's immune response, volunteers received two additional vaccines at weeks 24 and 48. "These results must be interpreted with caution," Barouch warned.
"It remains to be determined whether an improved efficacy on RV144 will be achieved by any one or the other of the current efficacy trials," warned Dr. George Pavlakis and Dr. Barbara Felber of National Cancer Institute in Frederik, Maryland,
.
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