PROGRESS IN SEARCH FOR HIV VACCINE

Researchers have discovered two powerful new antibodies to HIV that reveal what may be an Achilles heel on the virus.

The scientists at, and associated with, the International AIDS Vaccine Initiative (IAVI), at The Scripps Research Institute, and at the biotechnology companies Theraclone Sciences and Monogram Biosciences published their work in the Science journal this week.

Researchers will now try to exploit the newfound vulnerability on the virus to craft novel approaches to designing an AIDS vaccine.

Moreover, they say that the global collaboration and process that led to the discovery of the two new broadly neutralizing antibodies are likely to produce more such antibodies, which may in turn reveal additional vulnerabilities of HIV, adding still more vitality to the effort to develop a vaccine against HIV.

Any effective vaccine must provide protection from a diverse range of the most prevalent types of HIV circulating worldwide, but this is further made difficult by the constantly changing nature of the virus. The new antibodies however target a part of the HI virus which does not appear to change or mutate.

“These new antibodies, which are more potent than other antibodies described to date while maintaining great breadth, attach to a novel, and potentially more accessible site on HIV to facilitate vaccine design,” said Dennis Burton, professor of immunology and microbial science and scientific director of the IAVI Neutralizing Antibody Center at The Scripps Research Institute in La Jolla, California.

“So now we may have a better chance of designing a vaccine that will elicit such broadly neutralizing antibodies, which we think are key to successful vaccine development,” he explained.

“The findings themselves are an exciting advance toward the goal of an effective AIDS vaccine because now we’ve got a new, potentially better target on HIV to focus our efforts for vaccine design,” said Wayne Koff, senior vice president of research and development at IAVI. “And having identified this one, we’re set up to find more, which should further accelerate global efforts in AIDS vaccine development.”

The two newly discovered antibodies, called PG9 and PG16, are the first to have been identified in more than a decade and are the first to have been isolated from donors in developing countries, where the majority of new HIV infections occur.