While the finish line for the Coronavirus pandemic is not yet near, the world has another ammunition in its arsenal to take on the virus. Enter the ZyCoV-D vaccine.
The Drugs Controller General of India (DCGI) has given its chit of approval for ZyCoV-D to be administered to the adolescent population. This is a three-dose vaccine whose second and third doses are to be taken 28 and 56 days after the first.
This jab was approved after evaluating the interim phase III clinical trials results in consultation with the Subject Expert Committee. Interestingly, this vaccine is also the first COVID-19 vaccine candidate developed on a plasmid DNA platform to be commercially introduced anywhere in the world. Dr Asmita Mahajan, consultant neonatologist and paediatrician, SL Raheja Hospital, Mahim and Dr Gurudutt Bhat, consultant paediatrics, Fortis Hospital, Kalyan share more information about ZyCoV-D.
HOW DOES THE ZYCOV-D WORK?
This vaccine has demonstrated a primary efficacy of 66.66 per cent in phase 3 clinical trials. It is the first COVID-19 vaccine in India to be tested in the adolescent population — those in the 12-18-year age group. It is based on DNA-plasmid technology; then, 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. Zydus 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 IS A DNA-PLASMID VACCINE?
Now, 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.
WHAT’S ITS EFFECTIVENESS?
This vaccine has exhibited robust immunogenicity, tolerability and safety profile in the adaptive Phase I/II clinical trials carried out earlier. Both the Phase 1/2 and Phase 3 clinical trials have been monitored by an independent Data Safety Monitoring Board (DSMB).
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.
This brings more hope for life to soon begin as usual, but as always, we can’t let our guard down. Till the maximum proportion of our population gets vaccinated and we curtail the impact of COVID to the bare minimum, we will have to continue caution. COVID-appropriate behaviour will need to be followed come what may - until we win our war.