Cadila Healthcare testing two-shot regimen for ZyCoV-D, data likely by May

Ahmedabad-based drug major Cadila Healthcare is testing if a two-dose regimen of its DNA-plasmid vaccine ZyCoV-D works instead of a three-dose one, showing similar levels of efficacy.

 

The company is conducting phase 3 efficacy trials on a three-dose regimen of its DNA plasmid technology-based Covid-19 vaccine, which is in its last leg.

 

It expects to generate adequate data from clinical trials by May and subsequently seek approval from the country’s drugs regulator.

 

Sharvil Patel, managing director of Cadila Healthcare, told Business Standard the firm was working on trials to check if a two-dose regimen also worked.

 

Besides, the clinical trials of its vaccine are being conducted on children — 12 years and above.

 

“We would have sufficient data on the safety and efficacy of the vaccine on children by the time we seek approval from the regulator. Moreover, this is a needle-free vaccine, which may make it more acceptable to children,” Patel said.

 

Cadila Healthcare’s 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.

 

Patel thus said the vaccine might have higher acceptance among children scared of needles. ZyCoV-D is stable at room temperatures, making the logistics of the vaccine easier.

 

The firm had released preliminary data from animal trials in January, showing that its vaccine has induced an immune response in multiple animals.

 

Apart from generating neutralising antibodies after vaccination, the vaccine candidate has also induced a T-cell response, claimed the firm.

 

T cells are central players in the immune response to viral infection. Furthermore, the stability data showed that ZyCoV-D could be stored at 2 to 8 degrees Celsius for the long term and at 25 degrees Celsius for the short term (a few months).

 

Conventional vs DNA vaccine

 

Conventional active vaccines are made from a killed or weakened form of the infectious agent.

 

The DNA plasmid vaccine is a relatively new approach where a piece of DNA containing the genes for 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 specific antibodies against it.

 

DNA vaccines, Zydus said, have been shown to stimulate sustained immune responses.

 

Another advantage Zydus said was that the technology for producing the vaccine was simple and rapid, and, secondly, the DNA molecule was stable, had a long shelf life, and did not require a strict cold chain for distribution.