The Durg Controller General of India on Sunday gave the final approval to two vaccines against Covid-19 for restricted emergency use. With this, it can be expected that the vaccination drive in India will begin soon. All states and union territories have already conducted dry run of vaccines. With more than one vaccine now approved for emergency use, the scope of India’s first phase vaccination in which the frontline workers will be vaccinated at free of cost gets widened.
Here is all you need to know about these two vaccines:
Developers and manufacturers
Covishield has been developed by Oxford University in collaboration with pharma major Astrazeneca. India’s Serum Institute is their manufacturing and trial partner.
Covaxin is India’s first indigenous vaccine against Covid-19. It has been developed by Bharat Biotech in collaboration with the Indian Council of Medical Research and National Institute of Virology.
How the vaccines have been developed
Covishield uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.
Covaxin is an inactivated vaccine. An inactivated vaccine is one which is developed by inactivating (killing) the live microorganisims that cause the disease. This destroys the pathogen’s ability to replicate, but keeps it intact so that the immune system can still recognise it and produce an immune response. There are many inactivated vaccines against Hepatitis A, Influenza, Polio, Rabies, which offer “excellent protection”, Bharat Biotech has said.
Trial and efficacy
The Serum Institute of India submitted data of phase 1 clinical trial conducted over 23,745 overseas participants showing an overall result of 70.42 efficacy, the drug controller said. In phase two and three, which were conducted in India, 1,600 participants took part and the results were comparable to that of the first phase of trial, the drug controller said.
Bharat Biotech conducted phase one and two trials on 800 participants, apart from its several animal trials. Its third trial is going on and a total of 22,500 participants took part in it. The vaccine has been found effective and safe, the drug controller said.
India’s frontline workers will get the vaccine at free of cost, Union health minister Harsh Vardhan has already clarified. So the cost angle will come at a later stage of vaccination and also for other countries as several countries have shown interest in both the vaccine candidates. Covishield will cost around Rs 400, Serum Institute CEO Adar Poonawalla earlier said. Bharat Biotech’s vaccine is likely to cost less than Rs 100. But no final word on cost has been made yet.