Zydus Cadila on Thursday sought emergency use approval for its ZyCoV-D three-dose COVID-19 vaccine. According to the company, it is the "world's first Plasmid DNA vaccine". The company has completed Phase III trials. Dr. NK Arora, President of the Covid Working Group, had told on Sunday that Zydus Cadila's vaccine for children above 12 years of age likely to available by August. Earlier on July 18, Dr VK Paul, Member (Health) of NITI Aayog had told that Zydus Cadila has enrolled over 28,000 volunteers for its Phase III study.
If approval is granted to ZyCoV-D, it will become the fifth vaccine cleared for use in India after the Serum Institute of India's Covishield, Bharat Biotech's Covaxin, Russia's Sputnik V and the US-made Moderna. All these vaccines works on the two-dose regime.
ZyCoV-D is a DNA-plasmid vaccine that does use genetic material to elicit an immunogenic response in the body. The vaccine does not use the mRNA (messenger RNA), instead, it uses the plasmid DNA. A plasmid is a small DNA molecule within a cell that is distinct from chromosomal DNA and can replicate independently and is usually found in bacterial cells.
Unlike the other vaccines, ZyCoV-D works on a three-dose regimen. The reason for the three-dose regimen is that it will offer a longer immune response and has shown better results in Phase 1 and Phase 2 trials. The company is also testing a two-dose regimen. This vaccine clinically tested on 28000 volunteers, which is the largest clinical trial in the country. The trials included all age groups, including children aged 12 to 18 years.
