New Delhi: An international consortium of HIV researchers, searching the globe for a rare, specialized type of HIV patients known as “elite neutralizers”, is now scouring India with the hope that it will find such people who could help in the race to find a vaccine for the formidable, highly infectious virus.
Elite neutralizers are among a niche subset of HIV patients who, despite being infected with the virus, show a fraction of the levels of viruses that circulate and eventually destroy the body when infected. Though such neutralizers, too, eventually fall prey to the infection, their relative resilience comes from having immune systems that produce a class of specialized, rare antibodies called broadly neutralizing antibodies (BNABs), which in turn hold key clues to designing potential vaccines.
Thus far, only 18 individuals from the US, Australia, Europe and Africa have been classified as elite neutralizers. Extending the search to HIV patients in India, according to researchers involved, will accelerate efforts to develop a potential HIV vaccine.
Sex workers attending HIV awareness session at Ashodya. File photo
The project involves the International AIDS Vaccine Initiative (IAVI), an international agency that works on research and advocacy around HIV. “We are looking to begin next year and are awaiting formal approval from the department of biotechnology,” said Rajat Goyal, country director (India) at IAVI. “Finding more elite neutralizers from India will substantially aid efforts to develop a preventive vaccine for AIDS.”
The newly launched Translational Health Science and Technology Institute (THSTI) will also contribute to the project, said Maharaj Kishen Bhan, secretary, department of biotechnology.
“THSTI has a vaccine development programme,” he said. “It will be involved in examining the samples of such neutralizer population.”
There are several antibodies that the immune system produces to fight infections, especially those that are viral in nature. However, the sheer diversity of HIV viruses, coupled with rapid mutation rates, means that most viruses escape detection by these antibodies. BNABs are a smarter class of antibodies that are able to identify more weak spots on the offending virus’ surface and prevent it from targeting the immune system.
“As of now, what we’ve seen is that BNABs are able to block at least 70% of the different kinds of viruses in an HIV infection,” said Wayne Koff, chief scientific officer at IAVI. Koff was one of the scientists involved in seminal work that discovered new kinds of BNABS. “Recently, we’ve found two more BNABS that are effective against subtypes of the HIV virus commonly found in Africa and India. All of this will hopefully contribute towards the design of a vaccine.”
While a vaccine for HIV has eluded researchers, the rate of new HIV infections has been declining globally.
There were 2.7 million new HIV infections worldwide in 2010, 15% fewer than in 2001, and 21% below the number of new infections at the peak of the epidemic in 1997, according to a report by UNAIDS made public on Monday. India has an HIV/AIDS population of about 1.5 million, according to a recent report by BMJ, a British medical journal.
Koff’s views come on the back of a resurgent optimism among AIDS researchers over developing an AIDS vaccine. In 2009, researchers announced that an HIV vaccine trial in Thailand had reduced the risk of contracting HIV by one-third. “It’s certainly not enough to be called a protective vaccine, but enough to merit serious investigation,” according to Koff. “It’s the first positive news on the HIV vaccine front for decades.”
The search for elite neutralizers reflected a new, well thought-out approach to the idea of designing a vaccine, said Shahid Jameel, an HIV researcher at the International Centre for Genetic Engineering and Biotechnology, New Delhi.
“All previous failed attempts have focused on designing a vaccine that is similar to existing vaccines such as those for hepatitis,” Jameel said. “This approach of trying to build a vaccine, in a kind of reverse engineering approach by isolating antibodies, is based on our recent understanding of the immune system. It may be successful, but it is certainly a very long time away.”