What will make India's ZyCoV-D a Global first COVID vaccine

This will be the second home-grown COVID vaccine if the Drug Controller General of India (DCGI) gives it a nod for emergency use. Globally, ZyCoV-D will be the first DNA vaccine to counter the SARS-CoV-2 virus as Indian drugmaker Zydus Cadila applies for its emergency use approval. That’s not all. This will also be a three-dose COVID-19 vaccine that can be administered to all above the age of 12.

Zydus Cadila claims that it has conducted the largest clinical trial in over 50 centres across India for its plasmid DNA Vaccine ZyCoV-D which involved the adolescent population in the 12-18 years age group. Around 1000 subjects were enrolled in this age group and the vaccine was found to be safe and very well tolerated. The tolerability profile was similar to that seen in the adult population.

‘ZyCoV-D vaccine shows 66.6% primary efficacy’

The pharma company says that the vaccine attained primary efficacy of 66.6% for symptomatic RT-PCR positive cases in the interim analysis. Whereas, no moderate case of COVID-19 disease was observed in the vaccine arm post administration of the third dose suggesting 100% efficacy for moderate disease. No severe cases or deaths due to COVID-19 occurred in the vaccine arm after administration of the second dose of the vaccine.

“This breakthrough marks a key milestone in scientific innovation and advancement in technology. As the first-ever plasmid DNA vaccine for human use, ZyCoV-D has proven its safety and efficacy profile in our fight against COVID-19. The vaccine, when approved, will help not only adults but also adolescents in the 12 to 18 years age group,” says Dr. Sharvil Patel, Managing Director, Cadila Healthcare Ltd.

‘ZyCoV-D vaccine can be easily adapted to deal with mutations’

Zydus Cadila claims the ZyCoV-D vaccine exhibited robust immunogenicity and tolerability and safety profile in the adaptive Phase I/II clinical trials carried out earlier. Both the Phase I/II and Phase III clinical trials were monitored by an independent Data Safety Monitoring Board (DSMB). The pharma company says the plug-and-play technology on which the plasmid DNA platform is based, is ideally suited for dealing with COVID-19 as it can be easily adapted to deal with mutations in the virus, such as those already occurring.

In another development, the Company has also evaluated a two-dose regimen for ZyCoV-D vaccine using a 3 mg dose per visit and the immunogenicity results had been found to be equivalent to the current three-dose regimen. This will further help in reducing the full course duration of vaccination while maintaining the high safety profile of the vaccine in the future.

How ZyCoV-D is different from other vaccines

1. The plasmid DNA vaccine after injection will produce the spike protein of the SARS-CoV-2 virus and elicit an immune response in the body in protection from disease.

2. Three doses, intradermal vaccine, will be applied using a needle-free system, which can also lead to a significant reduction in side effects.

3. The vaccine can be stored at 2-8^oC but shows good stability at temperatures of 25^oC for at least three months.

4. The thermostability of the vaccine will help in easy transportation and storage of the vaccine and reduce any cold chain breakdown challenges leading to vaccine wastage.

5. The plasmid DNA platform provides ease of manufacturing with minimal biosafety requirements (BSL-1).

Zydus was the first company in India to develop and indigenously manufacture the vaccine to combat Swine Flu during the pandemic in 2010. In the past, it has also indigenously developed numerous vaccines successfully including tetravalent seasonal influenza vaccine, inactivated Rabies vaccine, Varicella vaccine, Measles containing vaccines, Typhoid conjugate vaccine, pentavalent vaccine (DPT-HepB-Hib), etc.