HIV superinfection may hold clues to vaccine development

U.S. researchers recently showed that women who have been infected by two different strains of HIV from two different sexual partners have a more robust antibody response than those with only one strain.

The researchers tracked the immune activity of 12 HIV-positive Kenyan women with superinfections, infections by two different strains of HIV from two different sexual partners, over the period of five years. They compared the results to a control group of three singly infected women monitored during the same period, according to

The study, written by scientists at the Fred Hutchinson Cancer Research Center in Seattle, was recently published in the journal PLoS Pathogens.

"We found that women who had been infected twice not only had more potent antibody responses, but some of these women had 'elite' antibody activity, meaning that they had a broad and potent ability to neutralize a wide variety of strains of HIV over a sustained period time," senior author Dr. Julie Overbaugh said, reports. "Individuals who become superinfected with a second virus from a different partner represent a unique opportunity for studying the antibody response and may provide insights into the process of developing broad neutralizing antibodies that could inform HIV-vaccine design."

The study suggests that being infected with a mixture of different viral strains of HIV may be one way to boost antibody response. The study also suggest that infection by two strains leads to a more rapid antibody response that is capable of identifying other strains.

"The holy grail of an HIV vaccine is to elicit antibodies to the virus because antibodies have been shown to block virus infection," Overbaugh said, according to "But there has been little progress in determining how to elicit such antibodies with a vaccine. The study of individuals HIV infected who have developed strong antibody responses to the virus may shed light on the best approach to design a vaccine that will induce an effective immune response."