In a major breakthrough in vaccine development for Covid-19, Zydus Cadila (Cadila Healthcare) on Wednesday announced safety of its plasmid DNA vaccine in the first phase of clinical trials on healthy subjects.

The company announced, that its “plasmid DNA vaccine to prevent Covid-19, ZyCoV-D was found to be safe and well tolerated in the Phase I clinical trial.”

The company will now commence Phase II clinical trials from August 6. The Phase 1 clinical trials had begun on July 15.

The doses of the vaccine administered to healthy volunteers in the Phase I clinical trial has been well tolerated, the company reported.

Previously, the vaccine was found to be safe, immunogenic and well tolerated in the pre-clinical toxicity studies. The vaccine was able to elicit high level of neutralising antibodies in animal studies.

“The Phase I dosing to establish the safety of ZyCoV-D is an important milestone,” said Pankaj R Patel, Chairman, Zydus Cadila. All the subjects in Phase I clinical trial were closely monitored in a clinical pharmacological unit for 24 hours post dosing for safety and for 7 days thereafter and vaccine was found to be very safe. We now begin the Phase II clinical trials and look forward to evaluating the safety and immunogenicity of the vaccine in a larger population,” he added.

Phase II study

The Phase II study of ZyCoV-D will be conducted in over 1,000 healthy adult volunteers as part of the Adaptive Phase I/II dose escalation, multicentric, randomised, double-blind placebo controlled study.

The seven day safety of the vaccine in all the subjects enrolled in the Phase I clinical trial has been endorsed by the independent Data Safety Monitoring Board (DSMB) - constituted to oversee the safety aspects of the clinical trial.

With ZyCoV-D, the Company has successfully established the DNA vaccine platform in the country using non-replicating and non-integrating plasmid carrying the gene of interest making it very safe.

Further, no vector response and with absence of any infectious agent, the platform provides ease of manufacturing the vaccine with minimal biosafety requirements (BSL-1).

The platform is also known to show much improved vaccine stability and lower cold chain requirements making it easy for transportation. Furthermore, the platform can be rapidly used to modify the vaccine in couple of weeks in case the virus mutates to ensure that the vaccine still elicits protection.

The plasmid DNA when introduced into the host cells would be translated into the viral protein and will elicit a strong immune response mediated by the cellular and humoral arms of the human immune system, which play a vital role in protection from disease as well as viral clearance.

Zydus also acknowledged the support of National Biopharma Mission, BIRAC, Department of Biotechnology, Government of India in the development of ZyCoV-D.

Cadila Healthcare shares gained nearly 2 per cent in early trades on BSE to trade at ₹409.60.

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