Updated: November 8, 2021 7:55:54 am
India is all set to get a fourth Covid vaccine this month with the Centre placing orders for 1 crore doses of Gujarat-based Zydus Cadila’s three-dose candidate. The vaccine, ZyCoV-D, has already been granted emergency use authorisation for adults and children above 12, making it potentially the first to be administered to the adolescent population in India.
Top government sources told The Indian Express that the needle-free vaccine, which has demonstrated primary efficacy of 66.66 per cent in phase 3 trials, will be made available “within November” — and “final deliberations” are being held to decide on its use among children.
The Centre’s move also paves the way for the use of the first Covid vaccine in the world to be developed on a DNA platform where the SARS-CoV-2 spike proteins are reproduced to create antibodies.
According to sources, the Covid standing committee of the National Technical Advisory Group on Immunization (NTAGI), which is India’s apex advisory body on immunisation, is currently discussing two key aspects of the use of ZyCoV-D.
“First, NTAGI is looking at the use of this vaccine for adults. Approximately 70 crore of the estimated eligible adult population of 93 crore have received their first dose. That leaves us with a small group. NTAGI will take a call on which category in this group would be given the DNA vaccine,” the sources said.
“Second, NTAGI is in final deliberations to recommend this vaccine’s use in the adolescent population. This vaccine should be available within November after these two decisions are taken,” sources said.
So far, three vaccines have been administered in India’s immunisation drive: SII’s Covishield (95.69 crore doses), Bharat Biotech’s Covaxin (12.22 crore doses) and the Russian Sputnik vaccine (10.9 lakh doses).
ZyCoV-D, which uses the “plug and play” technology, has a DNA plasmid vector that carries the gene encoding the spike protein present on the surface of SARS-CoV-2, which causes the Covid infection. When the DNA plasmid is injected into the human cell, it enters the nucleus and reproduces spike proteins. In response, the human body generates antibodies.
According to Zydus, its technology is “ideally” suited for tackling Covid as it can be easily adapted to deal with mutations in the virus.
The DNA vaccine platform has, broadly, three advantages:
- It is an intradermal vaccine, which is applied without the conventional needle, which reduces pain at the injection site.
- Unlike mRNA vaccines, which need ultra-cold storage systems, the DNA vaccines can be stored at 2-8 degrees Celsius that is best suited for India’s requirement.
- Its manufacture does not require the setting up of a BSL-3 high containment facility as is required in the production of inactivated virus vaccines like Covaxin. Instead, the vaccine can be manufactured with minimum biosafety requirements.
However, the DNA vaccine is being introduced at a time when the country has a surplus of Covid vaccines. According to Health Ministry data, more than 116.58 crore doses have been supplied to states, and 15.77 crore doses are still available to be administered.
In July, Zydus had said that it plans to manufacture 10-12 crore doses annually. On August 20, when it received EUA from the drug regulator, the company had announced that it had begun stockpiling its DNA vaccine.