Science
All you need to know about Zydus’ covid vaccine ZyCoV-D
Summary
Ahmadabad-based drugmaker Zydus Cadila has applied for an emergency-use authorization for its three-dose covid-19 vaccine ZyCoV-D. With a 'primary efficacy' of 66.6%, the jab, if approved, will be the world’s first DNA vaccine. Mint explains:Ahmadabad-based drugmaker Zydus Cadila has applied for an emergency-use authorization for its three-dose covid-19 vaccine ZyCoV-D. With a 'primary efficacy' of 66.6%, the jab, if approved, will be the world’s first DNA vaccine. Mint explains:
What kind of vaccine is ZyCoV-D?
ZyCoV-D is a three-dose, plasmid DNA vaccine that produces the spike protein of the SARS-CoV-2 and elicits an immune response mediated by the cellular (T lymphocytes immunity) and humoral (antibody-mediated immunity) arms of the human immune system. It is also an intradermal vaccine, applied using a ‘needle-free injector’. Zydus claims the needle-free system can lead to a significant reduction in side effects. The vaccine uses a ‘plug and play’ technology on which the plasmid DNA platform is based. It also means that a new form of the vaccine can be rapidly generated against any variant.
What is a plasmid DNA vaccine?
Plasmids are DNA molecules that replicate independently from the host’s chromosomal DNA. They are mainly found in bacteria. A plasmid DNA vaccine involves injecting into the appropriate tissues a plasmid containing the DNA sequence encoding of the antigen against which an immune response is sought, and relies on the in-situ (original) production of the target antigen. This approach offers a number of potential advantages over traditional approaches, including the stimulation of both B- and T-cell responses, improved vaccine stability, the absence of any infectious agent and the relative ease of large-scale production.
What is a plasmid DNA vaccine?
Plasmids are DNA molecules that replicate independently from the host’s chromosomal DNA. They are mainly found in bacteria. A plasmid DNA vaccine involves injecting into the appropriate tissues a plasmid containing the DNA sequence encoding of the antigen against which an immune response is sought, and relies on the in-situ (original) production of the target antigen. This approach offers a number of potential advantages over traditional approaches, including the stimulation of both B- and T-cell responses, improved vaccine stability, the absence of any infectious agent and the relative ease of large-scale production.
What is ZyCoV-D’s efficacy against covid?
Zydus claimed to have conducted the largest clinical trial for a covid-19 vaccine in India in over 50 centres. This was also the first time that any covid-19 vaccine had been tested in the 12-18-year age group in the country. Around 1,000 subjects were enrolled in this age group and the vaccine was found to be safe. The tolerability profile was similar to that seen in the adult population. Primary efficacy of 66.6% has been attained for symptomatic RT-PCR positive cases in an “interim analysis".
How many doses can Zydus produce?
Zydus Cadila has said it plans to manufacture 100-120 million doses of ZyCoV-D annually. Zydus will also be partnering with contract manufacturing organizations where it could potentially transfer its technology to produce another 50-70 million doses of the vaccine. The pharma company will be manufacturing the vaccine at its plant at the Zydus Biotech Park in Ahmedabad, Gujarat. It has invested ₹400-500 crore on clinical trials and scaling up manufacturing capacity.
