(RxWiki News) As the saying goes, there's a silver lining to every cloud. Even when it comes to being infected with HIV not once, but twice.
Researchers studying women who had been infected with two different strains of HIV – a so-called 'superinfection' – found that they had a big boost in their ability to fight off the virus, compared to women who were infected with one strain.
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The study was conducted by researchers at Fred Hutchinson Cancer Research Center in Seattle, and published in the open-access journal PLOS Pathogens. The research may inform future HIV vaccine design.
The researchers were looking for antibodies that had the ability to neutralize the virus. They went in search of HIV patients with 'superinfections' to study how the body reacted to two diverse strains of the virus, with a mind towards designing HIV vaccines.
A superinfection is rare. There are only 50 known cases in the world, according to data from the Terrence Higgins Trust. It occurs when a person has been infected from two sexual partners.
The researchers found 12 women with superinfections in Kenya, and monitored their immune response for five years. They were compared to three women who were also HIV positive, but had only been infected once.
Senior author Dr. Julie Overbaugh and lead author/doctoral student Valerie Cortez assessed how the women's antibodies were able to neutralize the other strains of HIV that they were exposed to. Then, they compared the results to see if two viruses were better than one.
The women with the superinfections had 70 percent more antibodies, and their ability to fight off HIV was 50 percent stronger.
In a statement, Dr. Overbaugh said that some of the superinfected women had the unique ability to neutralize, or fight back, many strains of HIV over time.
The scientists don't know how the double infection works to boost immune response. But they are now investigating the possibilities.
They hope that this unique finding will aid in the search for an effective HIV vaccine, which could slow the virus' spread and end the epidemic.
The research was published in March 2012.