Zydus Cadila announced on 2 February that they have started supplying their three-dose COVID-19 vaccine, ZyCoV-D, to the centre.

A statement released by the company also said that they plan to make the vaccine availabe in the private market as well.

The vaccine is the "world's first and India's indigenously developed DNA-based vaccine for COVID-19 to be administered in humans, including children and adults, 12 years and above," the Centre said in a statement, back August.

The Zydus Cadila vaccine has also been approved for children over 12 years, although, it hasn't been rolled out for kids yet.

Because DNA vaccine is a considerably new technology, experts are not too convinced of its efficacy and safety without clinical trial data to back the claims.

"We have never had a licensed DNA vaccine for humans. I'd be very supportive but I would like to see the phase 3 data before thinking this is a valuable addition," Moneycontrol quoted Dr Gagandeep Kang, Virologist, Professor, Christian Medical College, Vellore in an earlier article.

How much do you know about the indigenous vaccine?

What kind of a vaccine is it? How does it compare to Covaxin and Covishield? When will we get it? FIT gets you up to speed on everything we know about the vaccine.

ZyCoV-D is a Plasmid DNA vaccine.

The DNA (And RNA) vaccines—a relatively new technology developed for the first time only in the 1990s—don't introduce a weakened form of the pathogen like traditional vaccines.

The Zydus vaccine is the first DNA vaccine to be produced in India.

In theory, DNA vaccines produce the same results as mRNA vaccines, and so the efficacy of the Zydus vaccine too is likely to be in the realm of the other mRNA vaccines already in the market, including Moderna, Pfizer, and Johnson & Johnson.

One advantage that DNA vaccines have over their mRNA counterparts is that they are more stable in higher temperatures, making them more suitable for use in warmer countries like India.

Furthermore, the (DNA vaccine) 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 Zydus Cadila Vaccines are the first needle free vaccine in the world, administered intradermally using the painless PharmaJet needle free system.

The vaccine doses come with seperate specialised applicators.

According to the company, Zydus Cadila's three dose vaccine is to be taken with a gap of 28 days between each dose.

According to the statement put out by Zydus Cadila, each vaccine dose will cost Rs 265. The applicator will be sold seperately at Rs 93 per dose. This is excluding GST.

Although the company had initialy planned on launching the vaccines in the market in mid 2021, it faced some delay.

Now that the first consignment of the vaccines has been supplied to the central governement, the process is likely to speed up. The vaccines are expected to be available in government facilities soon.

The company also said that they were planning on supplying to private players as well.

In their statement, the company announed that they have entered an agreement with Shilpa Medicare Limited, a contract manufacturing organisation, to produce an undisclosed, 'mutually agreeble' number of doses of th vaccine.

• Zydus vaccine has the same goal, and is likely to have the same results as the two existing homegrown vaccines, but where it differs is in the way it works.

Covaxin is a whole inactive virus type vaccine, and Covishield is a non-replicating viral vector type vaccine.

Both of which are relatively traditional, well established types of vaccine technology that work by introducing a part (in the Oxford vaccine it is the gene protein spikes found on the virus’ surface) or whole of the virus in a ‘harmless’ form to trigger the immune system into producing a large number of antigens to fight the actual virus.

The Zydus vaccine, as explained, is a DNA vaccine that delivers only a specific set of instructions to our cells that instructs our immune system to recognize and respond to the virus.

The Zydus vaccine is also India’s first plasmid DNA vaccine.

• Unlike Covishield and Covaxin, ZyCoV-D is being tested as a 3 dose vaccine.

• While it can be stored in normal refrigerator temperatures of 2 - 8 degrees Celcius like Covishield and Covaxin, the company also claims that the vaccine is very thermostable at up to 25 degrees.