Context: Recently, Gujarat-based Zydus Cadila’s three-dose Covid-19 vaccine was granted emergency use authorisation for use in adults and children above 12 years, making it potentially the first vaccine to be administered to the adolescent population in India.

• It is the second home-grown shot to get emergency authorisation in India after Bharat Biotech's Covaxin.

About ZyCoV-D

• Zydus Cadila's vaccine, developed in partnership with the Department of Biotechnology under the ‘Mission COVID Suraksha’ and implemented by the Biotechnology Industry Research Assistance Council.
• It is developed on a plasmid DNA platform which is commercially introduced anywhere in the world.

Effect and Working

• It uses the ‘plug and play’ technology, has a DNA plasmid vector that carries the gene encoding the spike protein present on the surface of SARS-CoV-2, which causes the Covid-19 infection. 
• When the DNA plasmid is injected into the human cell, it enters the nucleus and reproduces spike proteins. In response, the human body generates antibodies.

It is the world's first plasmid DNA vaccine against the coronavirus. 

• Unlike mRNA vaccines, DNA-based vaccines do not require ultra-cold storage systems and are said to be more cost-effective. 
• It uses a section of genetic material from the virus that gives instructions as either DNA or RNA to make the specific protein that the immune system recognises and responds to.
• This vaccine was effective against the new coronavirus mutants, especially the Delta variant, and that the shot is administered using a needle-free applicator as opposed to traditional syringes.

Additional Information

• In 2010, Zydus became the first company to develop and indigenously manufacture a vaccine against swine flu. 
• The company earlier developed the tetravalent seasonal influenza vaccine and the inactivated rabies vaccine.