India’s 'first' indigenous vaccine candidate has been injected into three people, and reportedly been “tolerated well”. The vaccine candidate, called Covaxin, is being jointly developed by ICMR and Hyderabad-based Bharat Biotech.
On June 29, the company received the drug regulator’s approval for phase one and phase two clinical trials on human participants.
“Human trials with Corona vaccine of Bharat Biotech started at PGI Rohtak today. Three subjects were enrolled today. All have tolerated the vaccine very well. There were no adverse events,” Anil Vij, Haryana minister for health, home, science and technology, said in a tweet on Friday.
According to ICMR, 1,000 human participants will be tested over two phases. “Covaxin initiated phase-1 clinical trials across the country on July 15. The trials began at AIIMS, Patna. This is a randomised, double-blind, placebo- controlled clinical trial in 375 volunteers in India,” a Bharat Biotech spokesperson told THE WEEK.
The PGI, Rohtak is one of a dozen sites that had been selected for human trials for Covaxin, according to the ICMR. A letter was also sent out to the principal investigators of each of these sites to fast track the two trial phases by recruiting participants by July 7. The letter became controversial since it mentioned a deadline of August 15, leading to concerns by various experts over the safety and efficacy of a vaccine if trials were rushed, or key processes were compromised.
The trials that began today are crucial since in phase one and two human clinical trials, a vaccine candidate is tested for safety and immune response. Once a vaccine candidate has proven safety and initiated sufficient immune response in human participants, a phase 3 trial gets initiated to test its efficacy on a large number of people.
The indigenous, inactivated vaccine is being developed and manufactured in Bharat Biotech’s BSL-3 (Bio-Safety Level 3) High Containment facility located in Genome Valley in Hyderabad. Across the world, several kinds of technologies are being deployed to develop a COVID vaccine. An inactivated vaccine such as Covaxin, however, is a kind of whole virus vaccine where the virus is weakened to an extent that it can generate an immune response but can't cause disease.
"Whole virus vaccines are of two types—live attenuated such as oral polio vaccine and inactivated vaccines such as injectable polio vaccine. Both are very successful vaccines. Inactivated vaccines have an advantage in that they are easy vaccines to develop. However, the disadvantage is that since they are chemically inactivated, it is possible that the architecture of proteins on the surface of the virus or even inside the virus would have changed, and T-cell [key part of the immune system] responses are not going to be as one would get in a live virus. Live attenuated vaccines on the other hand, give better immune responses since they are able to replicate inside the body, and initiate T-cell immunity," according to Dr Shahid Jameel, noted virologist, CEO, Wellcome Trust/DBT-Indian Alliance.
