Indian researchers have stumbled upon a handful of early leads in their pursuit of a vaccine against HIV, but it would probably take decades before these leads are translated into a commercial vaccine against Aids.

Analysing blood samples of 128 HIV positive persons, a group of young Indian scientists found four “neutralising antibodies” that can block entry of the human immunodeficiency virus in a human cell. Scientists are analysing if any one of these four antibodies or a combination of them can be used as a vaccine against HIV.

“We have seen good signals in four samples. But more research needs to be conducted,” said Bimal Chakraborty, who heads the group at the International Aids Vaccine Initiative laboratory at the Translational Health Science and Technology Institute, here that got the leads.

The research is a part of Protocol-G, a scientific programme to fish out such neutralising antibodies (a type of protein) from blood samples of HIV infected individual.

The researchers received 200- blood samples from Chennai based non-governmental organisation YRG Care led by Suniti Solomon, who reported the first HIV case in India in the 1980s.

“Out of 200 samples, we studied 128 samples so far and will complete the rest by the first quarter of 2014. By the end of next year, we hope to find out which one of these leads are worth pursuing further,” Rajat Goyal, IAVI country director told Deccan Herald.

IAVI and its partners have isolated a number of antibodies from HIV positive donors from around the world. Researchers believe that these antibodies hold vital clues to the design of an effective AIDS vaccine.

The agency recently launched the Indian arm of Protocol-G to identify such antibodies from Indian samples infected by the Indian strain, known as Clade-C sub-type of HIV.

Notwithstanding the failure of several candidate HIV vaccines in clinical trials, scientists said there were few major advancements in the last one year that would provide better insight into vaccine development.

“At least two laboratories have identified the outer protein of the virus and made its crustal structure. We know there are four vulnerable spots,” said Wayne C Koff, IAVI chief scientific officer.

“We will examine if the Indian proteins are acting against these four vulnerable sites on the outer shell of the virus or is there a fifth or sixth vulnerable spot,” said Koff, an adjunct professor in the State University of New York, Stony Brook.