ZyCov-D vaccine, the world’s first DNA vaccine

Category
Science & Technology
Published
14th Jul, 2021

Ahmedabad-based ZydusCadila has applied to Central Drugs Standard Control Organisation (CDSCO), the national drugs regulator, seeking emergency use authorisation (EUA) for ZyCov-D, its Covid-19 vaccine.

Context

If approved by the regulator, ZyCov-D will be the world’s first DNA vaccineagainst infection with SARS-CoV-2.

About

About the ZyCov-D vaccine or DNA vaccine

ZyCov-D is a “plasmid DNA”. These DNA are engineered to show the desired results.
The plasmids used in the vaccine are coded with the instructions to make the spike protein of SARS-CoV-2.

Plasmid

A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA.
Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes.
Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance.

Vaccination gives the code to cells in the recipient’s body, so they can begin making the spiky outer layer of the virus.
The immune system is expected to recognize this as a threat and develop antibodies in response.
ZyCov-D will be given in three doses, with an interval of 28 days between the first and second and second and third shots.
No needle is used to deliver the vaccine, instead, a spring-powered device delivers the shot.
ZyCov-D has been developed with the support of the central government’s Department of Biotechnology and the Indian Council of Medical Research (ICMR).

Safety concerns

Safety concerns to integrate into cellular DNA or cause auto-immune diseases.

Emergency Use Authorization

In the current pandemic situation, it may not be possible to have all the evidence that a drug regulator would normally require for approving a drug, vaccine, device or test.
When there is a declared emergency, the regulator, in India’s case the DCGI, can take a call whether it is worth releasing a drug or vaccine that is not fully tested for efficacy and safety.
If there is evidence to suggest it may benefit patients, then the regulator is well within its rights to issue an emergency use authorisation to a medical product to make it widely available for use.

Vaccines approved under the EUA

The process for using the EUA is less clearly spelt out in India, but the DGCI has also been issuing EUAs based on clinical trial data.
In January, the DCGI approved the first two vaccines