ZyCoV-D: the plasmid vaccine
HOW DOES IT WORK?
ZyCoV-D comes
under the category of ‘nucleic acid’ vaccines. It uses a genetically engineered
vaccine, that are coded with direction to spike proteins of SARS-CoV-2. On vaccination
this codes function within the recipient’s body is to make spiky outer layer of
the virus thus eliciting an immune response by the production of antibodies for
protection and fight against the virus.
SAFETY AND EFFECTIVENESS:
The company states that they have conducted clinical trials around 50 centers across the country.
Dr. Sharvil Patel, MD, Cadila Healthcare Ltd, said that the adaptive Phase I/II clinical trial conducted earlier had shown promising result, exhibiting a robust immunogenicity, tolerability and safety profile.
Phase III trials have been conducted
with over 28,000 volunteers across India. Moreover, it was the first time any
Covid-19 vaccine had been tested on adolescent kids in the age group of 12-18
years.
“Around 1,000 subjects were enrolled in this age group and the vaccine was found to be safe and very well tolerated. The tolerability profile was similar to that seen in the adult population,” said Sharvil Patel at a briefing.
Both the Phase I/II and Phase III clinical trials have been monitored by an independent Data Safety Monitoring Board (DSMB).
“This breakthrough marks a key milestone
in scientific innovation and advancement in technology. As the first ever
plasmid DNA vaccine for human use, ZyCoV-D has proven its safety and efficacy
profile in our fight against COVID-19. The vaccine, when approved, will help
not only adults but also adolescents in the 12 to 18 years age group,” Dr. Patel
said.
It was observed that no serious case or
death have been reported since the second dose of vaccine has been administered.
There vaccine has attained a primary efficacy of 66.6% for symptomatic RT-PCR
positive cases in interim analysis. No moderate case of COVID-19 disease was observed in the
vaccine arm post administration of the third dose, which suggests 100% efficacy
for moderate disease
HOW IT DIFFERS FROM OTHERS?
The company said it had evaluated a
two-dose regimen for ZyCoV-D vaccine using a 3 mg dose per visit, and the
immunogenicity results had been found to be equivalent to the current
three-dose regimen.
The vaccine will come with Pharmajet,
a needle free applicator that determines pain free intradermal vaccination. Albeit
it would cost more, the company has yet to disclose the vaccine or the applicators
price.
The needle free applicator would help
to decrease the full course vaccination duration, simultaneously sustaining the
high safety profile of the vaccine in the future.
They can be manufactured easily as it
requires minimal biological safety levels (BSL-1) unlike attenuated vaccines (for
example small pox vaccine etc.) which require the top BSL-3 or BSL-4 units.
Zydus Cadila, till date have made an
investment of Rs500 crore for the vaccine project, including the current
production unit and had planned on producing 10-12 crore doses annually once it
gets regulatory approval. The gap between two doses (first and second dosage)
is 28 days.
