Bengaluru: While the scientist world over are working for developing an effective vaccine for Covid-29 pandemic, the scientists of the premier institute, the Indian Institute of Sciences (IISc) are also working on the same aspect.
A team of scientists led by Raghavan Varadarajan, Professor at the Molecular Biophysics are spending expertise in finding out an effective vaccine.
The studies related to the development of the vaccine were published in the Journal of Biological Chemistry and the Proceedings of the National Academy of Sciences respectively, according to IISc release here on Tuesday.
The COVID-19 vaccine is being developed by Varadarajan’s lab in collaboration with Mynvax, a startup co-founded by him and incubated at IISc, as well as several other institutes. When tested in guinea pig models, the vaccine candidate triggered a strong immune response.
Surprisingly, it also remained stable for a month at 37°C, and freeze-dried versions could tolerate temperatures as high as 100°C. Such ‘warm’ vaccines can be stored and transported without expensive cooling equipment to remote areas for mass vaccination ‒ most vaccines need to be stored between 2-8°C or even cooler temperatures to avoid losing their potency. Compared to newer types such as mRNA vaccines, making a protein-based vaccine like this can also be scaled up easily in India where manufacturers have been making similar vaccines for decades.
Prof Varadarajan said, “Now we have to get funds to take this forward to clinical development,” says Varadarajan. This would include safety and toxicity studies in rats along with process development and GMP manufacture of a clinical trial batch, before they are tested in humans. “Those studies can cost about Rs 10 crores. Unless the government funds us, we might not be able to take it forward.”
The study on HIV, the virus that causes AIDS, a disease for which there is no vaccine despite decades of research. The team, which included researchers from multiple institutes, sought to pinpoint which parts of the HIV’s envelope protein are targeted by neutralising antibodies ‒ the ones that actually block virus entry into cells, not just flag it for other immune cells to find. Vaccines based on these regions might induce a better immune response. To map such regions, researchers use methods like X-ray crystallography and cryo-electron microscopy, but these are time-consuming, complicated and expensive. Therefore, Prof Varadarajan and his team explored alternative approaches, and eventually arrived at a simpler, yet effective solution, the release added.
First, they mutated the virus so that an amino acid called cysteine would pop up in several places on the envelope protein. They then added a chemical label that would stick to these cysteine molecules, and finally, treated the virus with neutralising antibodies. If the antibodies could not bind to crucial sites on the virus because they were blocked by the cysteine label, the virus could survive and cause infection. Those sites were then identified by sequencing the genes of the surviving mutant viruses.
