New Insights into HIV Vaccine Development

• Acquired Immune Deficiency Syndrome (AIDS) is caused by HIV
• Currently, there is no vaccine to prevent HIV
• Duke researchers make strides in finding HIV vaccine
• New clues in immune systems of HIV-infected people hold the key to effective HIV vaccine development

Some people infected with HIV develop desired antibodies against the infection after several years, but an HIV vaccine is not able to induce the same immune response. This mystery baffled the scientists. A recent study published in the journal Science Immunology, conducted by Duke Human Vaccine Institute scientists tries to unravel the mystery, detailing new insights into HIV vaccine development.

Researchers studied 100 HIV-infected people - out of which 50 of them were people whose immune systems produced antibodies that are capable of neutralizing HIV, other 50 whose immune systems did not produce the antibodies.

The key differences in the immune system help in the development of a how-to manual for an effective HIV vaccine.

Facts about AIDS/HIV

Human immunodeficiency virus (HIV) weakens a person’s immune system by destroying the key cells that fight infection and disease. It is mainly transmitted through unprotected sex, shared needles, contaminated blood transfusions and during pregnancy.

The two main types of HIV strain include:

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HIV 1 - The most common type and is found worldwide

HIV 2 - Found mainly in Western Africa, with some cases in India and Europe

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• 36.9 million people are living with HIV/AIDS, of which 2.6 million are children
• In 2015 at least 2 million people enrolled newly on antiretroviral treatment
• In India, 2.1 million people are living with HIV
• Developing a safe, effective and affordable vaccine helps prevent HIV infection

“This work gives us the beginning of an understanding of the immune mechanisms that control the development of broadly neutralizing antibodies, which is a major goal of a successful HIV vaccine,” said Barton F. Haynes, M.D., director of the Duke Human Vaccine Institute and senior author of the study. “This moves forward important concepts for vaccine design to overcome a roadblock that has been present since we began this work 30 years ago.”


Previous work conducted by Haynes and colleagues, involved case study of a person with both HIV and a form of lupus erythematosus (autoimmune disease). The immune system of the person controlled both the virus and developed neutralizing antibodies. The immune disruptions that made the person develop lupus somehow enabled the neutralizing antibodies to carry on its function to fight the virus.

Results of the study revealed that HIV-infected people and individuals with autoimmune disease have similar immune alterations.

“In essence, HIV cloaks its vulnerable sites that the immune system wants to see by making them resemble our own tissues, thereby creating an environment in which the virus is protected and the beneficial antibodies are treated as a threat to the body”, said lead author Anthony Moody, M.D., chief medical officer of the Duke Human Vaccine Institute.

“These findings suggest that for a broadly neutralizing antibody-inducing HIV vaccine to be successful, we will need to mimic with vaccination the immune perturbations that occur in the setting of HIV infection,” Haynes said.

“The important point here is that the first step to finding a way around a roadblock, is to be able to understand the biology behind the problem,” Haynes said. “We now know what we need to do”

The next step in the research is to safely mimic the mechanism behind the infection and when the right antibodies are induced.

References:

1. What are HIV and AIDS? - (http://www.avert.org/about-hiv-aids/what-hiv-aids)
2. HIV/AIDS - (http://www.who.int/hiv/data/en/)
3. Global Statistics - https://www.aids.gov/hiv-aids-basics/hiv-aids- 101/global-statistics/)
4. HIV and AIDS in India - (http://www.avert.org/professionals/hiv-around- world/asia-pacific/india)

Source-Medindia