Decoding India’s First-of-its-Kind DNA Vaccine

Since the outbreak of COVID-19, we have witnessed two waves of this pandemic that have caused havoc. While our brave frontline workers continue to endlessly help people infected with the virus, our scientists and medical professionals are looking for best possible ways to prevent this virus from causing further harm. These experts studied different vaccines and tried and tested them in labs before moving forward with clinical trials in humans. Initially it seemed like a distant dream, but now they are not only being able to produce mass vaccines in a brief span of time but also developing different types and versions. And one such latest variant is the ZyCoV-D, the world’s first DNA vaccine produced by India. 

How do vaccines work?

You already know that our body has its own way of defending itself against pathogens (disease-causing organisms). Our skin, mucus and cilia work as a team to prevent any pathogens from entering the body. But, often, certain pathogens defeat our body’s defences – the immune system and enter our body and eventually make us fall sick. Our body then forms antigen-specific antibodies and works with the rest of the immune system to fight against these pathogens. Thus, for every new antigen, our body forms a specific antibody that can grab the antigen and defeat the pathogen. 

But our defence system might sometimes forget to produce antibodies against a certain antigen. Here comes the role of vaccines. Vaccines contain tiny inactive parts of a particular antigen that help trigger an immune response within the body. For instance, when we get a vaccine for smallpox, our body remembers the smallpox antigens and how it harms the body. So in the future, if the smallpox virus ever tries to enter our body, the immune system can easily identify it and produce suitable antibodies to fight against it. Just like how the smallpox vaccine helps prevent the smallpox virus from entering our body, COVID-19 vaccines also work similarly. While there are many vaccines around the world for the COVID-19 virus, one of its latest types is a DNA-based vaccine. 

Watch this interesting video to know the different types of COVID -19 Vaccines

  Also Read: Here’s Exactly Where We Are With COVID-19 Vaccines

What is a DNA-based vaccine?

As you already know, DNA and RNA are one of the basic building blocks of life. They are molecules that carry that genetic information which is passed on from parents to molecules.

Once administered, just like any other vaccine, a DNA-based vaccine also teaches our body’s immune system to fight the real virus. They insert a genetically engineered blueprint of viral genes into the DNA molecules (called plasmid). Once inside, it gives direct instruction to our body to build viral proteins, which the immune system recognises as foreign and triggers an immune response that protects us from the disease. 

The latest ZyCoV-D is also a DNA-based vaccine for the COVID-19 virus that recently got approval from the Drug Controller General of India (DCGI) to be tested on humans. 

Watch this video here to understand how Vaccines work against COVID-19

How does  ZyCoV-D work?

ZyCoV-D is the world’s first ever DNA-based vaccine against the SARS-CoV-2 virus. It is developed and manufactured by Zydus Cadila, an Ahmedabad-based pharmaceutical company. According to the World Health Organisation, this ‘radical fresh approach’ offers several advantages over traditional vaccines, including improved vaccine stability, the absence of any infectious agent and the relative ease of large-scale manufacture.

How is ZyCoV-D different from the other COVID-19 vaccines?

Unlike other intramuscular vaccines available around the world, ZyCov-D is very different in terms of mode of administration and the number of doses: 

1. ZyCoV-D is a genetic or nucleic acid vaccine. It is a three-dose vaccine that needs to be administered on day 1, day 28 and day 56. 
2. Unlike other vaccines, ZyCov-D is a needle-free Covid-19 jab. It uses the ‘Jet Injector’ method, a technique where the needle piercing the skin is replaced by pressure jet injecting the liquid directly through the upper layer of the skin and into the underlying tissues. This method is a great help for those who show hesitancy because of a fear of needles. Further, the absence of needles can also lead to a significant reduction in side-effects like pain at the injection-site, swelling, rash and arm soreness. 
3. As per the interim analysis from Phase 3 clinical trials, in over 28,000 volunteers, Zydus Cadila’s COVID vaccine has shown an efficacy rate of 66.6 per cent for symptomatic Reverse Transcription Polymerase Chain Reaction (RT-PCR) positive cases. 
4. Moreover, ZyCoV-D is the first vaccine candidate found to be eligible for use for children above the age of 12.

When will ZyCoV-D be available?

According to the team at Zydus Cadila, the vaccine will be made available within 45 to 60 days after getting the authorisation. This will be an innovative leap for India as we pave the path towards curing this deadly virus through genetic codes. 

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