The technique they are using for the possible vaccine simulates is a rare process found in some HIV-positive people’s immune system – the process decreases how much virus is in the body.
Both Harvard and Duke researchers are working on this method, but still say an actual vaccine for large-scale trials is not in the near future. Still, scientists are reasonably optimistic about the possibility – much more than they’ve been in some time.
Duke Human Vaccine Institute Director Barton Haynes said it’s the first time in 20 years after the discovery of the virus that researchers are attempting to create a vaccine using techniques applied to other diseases.
The problem is that HIV is constantly mutating to elude the immune system, and the body’s antibodies are not strong enough to protect the body.
Researchers found that 20 percent of people with HIV have immune systems that produce broadly neutralizing antibodies that can destroy many HIV strains via attacking the strains that remain consistent in the body, even when the virus changes.
The proteins can develop years after the initial infection, stopping the virus from duplicating but not curing them of it due to the hidden virus reservoir.
In earlier animal tests, the antibodies were infused with the proteins before HIV exposure, which prevented infections, but it was only a temporary solution.
Haynes and his team conducted lab tests on monkeys and mice as well as computer modeling to find out how to manipulate a non-compromised immune system to produce the special antibodies and continue making them stronger with every generation.
He said it’s a new way to create an HIV vaccine by controlling the broadly neutralizing antibodies to ensure they go down paths they typically do not go down. The vaccine would also be useful in training the immune system to create the antibodies in months rather than years after exposure.
An antibody-based vaccine has a greater potential to be effective than other treatment potentials. Three HIV vaccine candidates are currently involved in the final human testing stages, which will be deemed successful if they can protect half of the exposed population from actually getting the disease.
National Institutes of Health Vaccine Research Center Director Dr. John Mascola said the method would be beneficial because it introduces even stronger antibodies than other vaccine trials, which could result in an 80 to 90 percent effective vaccine.
Haynes and his team are a third of the way involved in the developing of the antibodies, and more types will be needed to ensure an effective vaccine. Haynes feels confident that this will be possible.
According to Mascola, it could be five or more years before an HIV vaccine is produced using the Haynes’ research.
Written by Mark Riegel, MD
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