Expert panel green signals Cadila's 3-dose DNA plasmid vaccine ZyCoV-D

DCGI nod expected soon; vaccine stable at room temperatures

The expert panel advising the Indian drug regulator has given its nod to the three-dose needle free Covid-19 vaccine from Cadila Healthcare (Zydus Cadila), claimed sources in the know. Once the Drugs Controller General of India approves the emergency use authorization (EUA), this would be the world’s first DNA-plasmid vaccine.

The Cadila Healthcare stock ended down 1.38 per cent on the BSE on Friday.

A source close to the development told Business Standard, “A regulatory approval is expected to come through anytime now. The process for that is on. The expert panel has given the green signal for the three dose regimen and is reviewing data on the two-dose regimen.” The three dose regimen is given on day zero, day-28 and day-56.

Meanwhile, Zydus had also submitted immunogenicity data from a two-dose regimen (using 3-mg doses) trial to the DCGI, which shows ‘equivalent immunogenicity’ with that of the three dose regimen. Therefore, a two-dose regimen approval is also expected. Sources claim the expert panel may review more data that it has sought.

The drug regulator could not be reached for a comment.

Zydus has invested Rs 400-500 crore in developing the ZyCoV-D so far, which includes setting up of manufacturing plants.

“We have re-purposed an existing plant where we are now producing, and our new plant will be ready by the end of July. By August, we should have a capacity to make 10 million doses a month and by the end of this year, we would have made 50 million doses of ZyCoV-D,” Sharvil Patel, managing director of Zydus Cadila had said earlier.

ZyCoV-D, the Covid-19 vaccine developed by Zydus Cadila has shown a 66.6 per cent efficacy in interim analysis of phase-3 trials that happened during the second wave of the pandemic in India. The vaccine has been already tested on adolescents aged above 12 years, and can also be stored at 25 degrees Celsius (or room temperature).

ZyCoV-D would be administered through a needle-free injection system (NFIS). Typically, in an NFIS, a jet of fluid is accelerated to high speed, providing it significant penetrating power through a fine-diameter nozzle when placed against the skin.

Zydus has also claimed that its vaccine works against the Delta variant; as the trials carried out in more than 50 clinical sites spread across the country and during the peak of the second wave of Covid-19 has shown the vaccine’s efficacy against the new mutant strains, especially the delta variant.

Zydus has submitted safety and tolerability data on adolescents from phase two clinical trials, and has generated data on 1,000 adolescents (between 12 and 18 years) from its phase-3 trials too. The Ministry of Health expects the vaccine would be available soon for adolescents. Trials on children above five years are also on the cards.

Conventional active vaccines are made of a killed or weakened form of the infectious agent. DNA plasmid vaccine is a relatively new approach where a piece of DNA containing the genes for the antigens is injected. The body then learns to develop an immune response against the antigen, and when the actual pathogen attacks, the body is able to generate the specific antibodies against it. DNA vaccines, Zydus has claimed, have been shown to stimulate sustained immune responses.

. ZyCoV-D is a plasmid DNA vaccine which when injected produces the spike protein of the SARS-CoV-2 virus and elicits an immune response

. 3-dose regimen – Day 0, Day 28, Day 56

. 2-dose regimen trial data shows equivalent immune response

. Will be administered through PharmaJet – needle free system Tropis

. Stored at 2-8 degree C but stable at 25 degree C for at least 3 months

. Can be made at BSL-1 labs

. Zydus invested Rs 400-500 cr on developing ZyCoV-D

. Capacity to make 10 mn doses per month from August

. Trial on children above 12 yrs over; plan to do trials on 5 yrs-plus