Zydus Cadila is likely to apply for emergency use authorisation (EUA) of its COVID-19 vaccine this month, after obtaining the first set of interim efficacy data.
"Now we are in the phase where we believe we have to get an event number. We believe this can be achieved this month. Once that outcome is achieved, we can submit the information (to the regulator) in the same month and eventually seek approval if the data is good," Sharvil Patel, the Managing Director of Zydus Cadila, told Mint.Phase 3 clinical trial for the plasmid DNA vaccine had started in February, with 28,000 participants. This trial is testing a three-dose regimen of the vaccine, taken at intervals of one-month.
The company is also testing a two-dose regimen of the COVID-19 vaccine, which is called ZyCoV-D. This two-dose regimen trial is also expected to be completed in May, Patel told the newspaper.
"If the data is equally good, we will look at it; but currently, we believe the three-dose regimen is more suitable for our vaccine and will give a better immune response and longer antibody response, which we have seen in our data," Patel was quoted as saying.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
The Ahmedabad-based drugmaker is planning to manufacture 10 million doses per month, to begin with, and subsequently raise it to 20 million doses.
Currently, two COVID-19 jabs are available in India -- Bharat Biotech's Covaxin and Covishield, the Oxford University-AstraZeneca jab manufactured by the Serum Institute of India. The Drugs Controller General of India (DCGI) has also granted emergency use authorisation to Russia's Sputnik V vaccine against COVID-19, but it has not been rolled out in the country yet.Follow Moneycontrol’s full coverage of the coronavirus pandemic here