The Drug Controller General of India (DCGI) granted emergency use approval to Zydus Cadila’s needle-free vaccine, ZyCoV-D, the world’s first ever DNA based vaccine against the SARs-COV-2 virus. Early last month, the Ahmedabad-based pharma-giant had sought permission from the government, stating that it had conducted the largest clinical trial for the vaccine in India.
Currently, Bharat Biotech’s Covaxin, Oxford-Astrazeneca’s Covishield, Russia-made Sputnik V, Moderna vaccine and Johnson & Johnson’s Janssen vaccine have received an approval for the Emergency Use Authorization (EUA), which makes ZyCoV-D the sixth COVID vaccine to be approved in India.
While all the vaccines aim to combat the deadly coronavirus, the newly approved COVID vaccine has its own special features and may be different in many ways.
Zydus Cadila’s ZyCoV-D is a ‘plasmid DNA’ vaccine that uses a non-replicating version of a DNA molecule called plasmid, which helps prepare a harmless version of the spike protein present on the SARS-COV-2 membrane.
Also known as the third-generation vaccine, DNA-based vaccines use engineered DNA to induce an immune response against the virus.
According to the World Health Organisation (WHO), this “radical new approach” offers several advantages over traditional vaccines, which include “improved vaccine stability, the absence of any infectious agent and the relative ease of large-scale manufacture.”
Zydus Cadila’s COVID vaccine is very different from other intramuscular vaccines available in and around the world. While all vaccines have been developed to fight the SARs-COV-2 virus, the mode of administration and the number of doses may differ, especially in respect to ZyCoV-D vaccine.
That said, here are some of the differences to note and how it compares with other COVID vaccines.
As compared to other COVID vaccines currently being administered in India, ZyCOV-D is a three dose regimen. According to Zydus Cadila, the three doses of ZyCoV-D are to be administered on day 0, day 28, and day 56. Reportedly, the company is also working on a two-dose vaccine.
In opposition to other COVID vaccines, Zydus Cadila’s coronavirus vaccine is a needle-free jab, which will use the ‘Jet Injector’ technique to administer the three doses. Instead of injecting the drug by piercing the skin with a needle, the vaccine will use high-pressure to inject the liquid directly through the upper layer of the skin and into the underlying tissues.
In the world of vaccine development, needle-free vaccines are not a new discovery so to say. It is an old technique, first demonstrated in 1866. This method of vaccination was also used during the 1960s for smallpox vaccination drives.
With the help of needle-free vaccines, side effects like pain at the injection-site, swelling, rash and arm soreness can be avoided, which is very prevalent in intramuscular injections.
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 RT-PCR positive cases. Following the third dose of the vaccine, it was noted that no moderate case of COVID was seen in vaccine beneficiaries.
In addition, there were no severe illness or death reported in people who had received the second dose of the vaccine. However, the data from the phase three trial is not yet peer-reviewed.
With respect to the current development, the Chairman of the Zydus Group, Pankaj R Patel said, “We are extremely happy that our efforts to put out a safe, well-tolerated and efficacious vaccine to fight COVID-19 has become a reality with ZyCoV-D. To create the world’s first DNA vaccine at such a crucial juncture and despite all the challenges, is a tribute to the Indian research scientists and their spirit of innovation. I’d like to thank the Department of Biotechnology, Government of India for their support in this mission of Atma Nirbhar Bharat and Indian Vaccine Mission COVID Suraksha.”
ZyCoV-D is the first vaccine candidate found to be eligible for use for children above the age of 12.
Bharat Biotech’s Covaxin is also in the running for developing effective vaccines for children. The vaccine is currently under trial for use among the 2 to 18-year-old age group.
According to the manufacturers, the vaccine will be made available within 45 to 60 days after getting the authorization. Reportedly, the company is set to manufacture 0 to 12 crore doses annually in the initial stages.
The pricing of the vaccine is yet to be revealed. As per Patel, “It is too early to comment on the pricing. That discussion is yet to happen. We will announce the price before the commercial launch of ZyCoV-D.”