An experimental vaccine that first primes the immune system, then boosts the immune system to amplify the response, could eventually become a strategy for protecting against global human immunodeficiency virus (HIV-1) infection, Johnson & Johnson has announced.

The announcement is based on the results of a small preclinical study, of an HIV vaccine regimen used in rhesus monkeys, conducted by scientists at Beth Israel Deaconess Medical Center (BIDMC), Crucell Holland B.V, one of the Janssen Pharmaceutical Companies of Johnson & Johnson, and several other collaborators.

The “heterologous prime-boost” vaccine regimen protected six out of 12 animals who received it from infection with the monkey version of HIV. The monkeys were given doses of SIV (simian, or monkey HIV) that were each 100 times more infectious than what humans are typically exposed to.

J&J has now begun a human phase 1/2a clinical trial for safety and immunogenicity of the vaccine, the first human AIDS vaccine test since 2009, with 400 volunteers in South Africa, Rwanda, Uganda, Thailand, and the U.S., with results expected next year.

Paul Stoffels, M.D., Chief Scientific Officer and Worldwide Chairman, Pharmaceuticals, Johnson & Johnson, said:

“Despite great progress in HIV treatments, HIV remains one of the greatest global health threats of our time with millions continuing to be infected each year. Our ultimate goal is to develop a vaccine that prevents HIV in the first place. By Janssen collaborating with multiple stakeholders on new tools, we hope one day to help eradicate HIV."

The vaccine consists of two parts: the first leverages Janssen’s AdVac, an adenoviral vectors technology, which involves a cold-causing virus “smuggling” HIV protein into the body to prime the immune system. The second part is a purified HIV envelope protein boost intended to enhance the immune system over time.

Lead author Dan H. Barouch, MD, PhD, Professor of Medicine at Harvard Medical School, said:

“We are very encouraged by the results of this preclinical HIV vaccine study, and the findings lead to a clear path forward for evaluating this HIV vaccine candidate in humans."

More than 35 million people around the world are now living with HIV, according to the Joint United Nations Programme on HIV/AIDS (UNAIDS).

Protective efficacy of adenovirus-protein vaccines against SIV challenges in rhesus monkeys Dan H. Barouch, Galit Alter, Thomas Broge, Caitlyn Linde, Margaret E. Ackerman, Eric P. Brown, Erica N. Borducchi, Kaitlin M. Smith, Joseph P. Nkolola, Jinyan Liu, Jennifer Shields, Lily Parenteau, James B. Whitney, Peter Abbink, David M. Ng’ang’a, Michael S. Seaman, Christy L. Lavine, James R. Perry, Wenjun Li, Arnaud D. Colantonio, Mark G. Lewis, Bing Chen, Holger Wenschuh, Ulf Reimer, Michael Piatak, Jeffrey D. Lifson, Scott A. Handley, Herbert W. Virgin, Marguerite Koutsoukos, Clarisse Lorin, Gerald Voss, Mo Weijtens, Maria G. Pau, and Hanneke Schuitemaker Science aab3886Published online 2 July 2015 [DOI:10.1126/science.aab3886]

Illustration: Cut-away model of HIV. Credit John Wildgoose, Wellcome Images

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