New Delhi: Bharat Biotech and Zydus Cadila kicked off human trials for their Covid-19 vaccine candidates this week, inoculating the first set of participants in what will be a closely watched race for an indigenous vaccine against the contagious virus.
What are these vaccines?
Bharat Biotech’s Covaxin is an “inactivated” vaccine, which is made using particles of the Covid-19 virus that were killed so that they would not be able to infect or replicate in those injected with it. Injecting particular doses of these particles serves to build immunity by helping the body create antibodies against the dead virus, according to the firm.
Zydus Cadila’s ZyCov-D is a “plasmid DNA” vaccine. DNA vaccines use genetically engineered plasmids–a type of DNA molecule–that are coded with the antigen (a toxin or substance given off by the virus) against which the immune response is to be built. The DNA sequence injected would match that of the virus, helping the body build antibodies against it.
When did the trials start?
Both Bharat Biotech and Zydus Cadila began vaccinating their first set of participants on July 15.
The first phase of the Covaxin trials are to be conducted on 375 participants across 12 clinical trial sites in the country, of which two–AIIMS Patna and PGIMS Rohtak–have begun the vaccination process.
The ZyCov-D phase I and II trials target 1,048 participants and are to be conducted at one site–Zydus Research Centre in Ahmedabad–according to the Clinical Trial Registry of India.
