Zydus Cadila’s ZyCoV-D, the country’s second indigenous jab against coronavirus (Covid-19), is soon going to be supplied to seven states in India, indicating that our vaccination program will gain more strengthen. This needle-less jab, which received authorisation from the Drugs Controller General of India (DCGI) on 20 August, will be initially administered only to adults because of the company’s limited production capacity currently. However, once the production capacity is strengthened, the vaccine will be available to adolescents too.
HERE IS WHAT YOU SHOULD KNOW ABOUT THE VACCINE
ZyCoV-D is the first Covid-19 vaccine that can be administered using a needle-free applicator as opposed to traditional syringes. It is a three-dose vaccine, whose second and third doses are to be taken 28 and 56 days after the first. The approval has come after evaluating the interim phase III clinical trials in over 28,000 volunteers, in consultation with the Subject Expert Committee. It is also the first Covid-19 vaccine candidate developed on a plasmid DNA platform to be commercially introduced anywhere in the world. The single dose of the vaccine will be made available to the Centre at Rs 376 including the cost of the jet applicator and GST, taking the price of a three-dose jab to Rs 1,128.
WHAT IS A DNA-PLASMID VACCINE?
Most active vaccines are made from a killed or weakened form of the infectious agent. A DNA-plasmid vaccine is a new approach where a piece of DNA containing the genes for the antigens is injected. The body learns to develop an immune response against the antigen, and when the pathogen attacks, the body can then generate the specific antibodies against Covid-19.
HOW DOES THE ZYCOV-D WORK?
The vaccine is jointly developed in partnership with the Department of Biotechnology, had demonstrated a primary efficacy of 66.66% in phase 3 clinical trials. It was the first Covid-19 vaccine in India to be tested in the adolescent population—those in the 12-18-yr age group. It is based on DNA-plasmid technology; it can be administered using a needle-free injection system; and finally, it remains stable in room temperatures for three months. Unlike mRNA vaccines, DNA-based vaccines do not require ultra-cold storage systems and are said to be more cost-effective. The manufacturer also claims that its technology is ideal for tackling Covid-19 as it can be easily adapted to deal with mutations in the virus.
WHAT’S ITS EFFECTIVENESS?
According to the data collected during this trial, this vaccine had already exhibited robust immunogenicity, tolerability and safety profile in the adaptive Phase I/II clinical trials carried out earlier. It said this vaccine works against the Delta variant as the trials have been carried out in more than 50 clinical sites spread across the country, and during the peak of the second wave of Covid-19, have shown the vaccine’s efficacy against the new mutant strains, especially the Delta variant. Data also shows equivalent immunogenicity with that of the three-dose regimen. Therefore, a two-dose regimen approval is also expected. However, the expert panel will review more data on the same.
Going forward, with more vaccines available to the population we can help ebb the pandemic and bring back normalcy to life. Until then, maintaining Covid-19 appropriate behaviour would remain paramount.
The writer is Chief Intensivist, Fortis Hospital, Kalyan.