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Bengaluru, November 10 (IANS): Researchers from the renowned Indian Institute of Science (IISc) in this tech city are developing vaccines to treat Covid-19 and HIV (human immunodeficiency virus), an official said Tuesday.
“Researchers have developed a heat-resistant Covid-19 vaccine candidate and a rapid method for identifying specific regions on the HIV envelope protein that are targeted by antibodies, which can help design effective vaccines,” he said. the official in a statement here.
Raghavan Varadarajan, the professor of the institute’s molecular biophysics unit, leads the team of researchers in vaccine development.
“The Covid-19 vaccine candidate contains a part of the novel coronavirus spike protein called the receptor binding domain (RBD), the region that helps the virus attach itself to the host cell,” the official said.
The vaccine candidate was developed in collaboration with Mynvax, a start-up, co-founded by Varadarajan and incubated in an institute’s laboratory.
“When tested on guinea pig models, the vaccine candidate triggered a strong immune response. It also remained stable for a month at 37 degrees Celsius, and the freeze-dried versions could tolerate temperatures up to 100 degrees Celsius,” noted the declaration.
Such “hot” vaccines can be stored and transported without expensive cooling equipment to remote areas for mass vaccination, although most vaccines need to be stored between 2-8 ° C or even colder temperatures to avoid losing the their power.
The difference between the vaccine developed at the institute and other Covid vaccines is that the candidate of the former uses only a specific part of the RBD, a string of 200 amino acids instead of the entire spike protein.
The researchers inserted genes encoding this part via a carrier DNA molecule, called a plasmid, into mammalian cells, which produced copies of the RBD section.
The team also found that the RBD formulation was as good as the full spike protein in triggering an immune response in guinea pigs, but much more stable at high temperatures for long periods.
“We need to get funding to take this forward to clinical development,” Varadarajan said, adding that it would include safety and toxicity studies in rats along with process development and GMP production of a clinical trial batch, before they are tested in beings. humans.
Since the studies can cost Rs 10 crore, the professor said the team may not be able to carry it out unless the government has funded it.
The second study focused on HIV, the virus that causes AIDS, a disease for which there is no vaccine despite decades of research.
The team, including researchers from other institutes, sought to identify which parts of the HIV envelope protein are targeted by neutralizing the antibodies and those that block the virus from entering cells, not signaling it to other immune cells.
“Vaccines based on these regions could induce a better immune response. To map these regions, the researchers use methods such as X-ray crystallography and cryo-electron microscopy while they are time-consuming, complicated and expensive,” the statement said.
Then, Varadarajan and his team mutated the virus so that an amino acid called cysteine appeared in different places in the envelope protein. They added a chemical tag to attach to these cysteine molecules and treated the virus with neutralizing antibodies.
“In principle, researchers could adapt this methodology to any virus, including Covid-19,” the statement added.
The studies were published in the “Journal of Biological Chemistry” and in the “Proceedings of the National Academy of Sciences”.
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