New Delhi: India recently approved the Oxford Covid-19 vaccine Covishield, manufactured by the Serum Institute of India, and Bharat Biotech’s Covaxin for restricted emergency use in the country.
In episode 653 of ‘Cut The Clutter’ Monday, the first in the new year, ThePrint’s Editor-in-Chief Shekhar Gupta discussed the compliments and complaints against the government’s decision, such as that it was in a rush to clear the Bharat Biotech vaccine.
The swadeshi vaccine has got a go-ahead even though phase 3 trials are under way and only preliminary data has been submitted to the government.
Gupta said that the “hasty clearance” is not fair to science, Bharat Biotech and the scores of scientists who contributed such as those at the Indian Council for Medical Research (ICMR), National Institute of Virology, Centre for Cellular and Molecular Biology, and Council of Scientific and Industrial Research.
Gupta, however, emphasised that Bharat Biotech is a world class company run by top class researchers, and its Covid vaccine uses a “tried and tested” method similar to the ones for Hepatitis B, rabies and polio. “Most of our families have, in the course of time, taken more than one vaccine from the two Indian manufacturers — Bharat Biotech and Serum Institute of India,” he added.
Gupta also remarked that he will “intrinsically trust in the vaccine” but quoted a Russian proverb, which goes, ‘trust but verify’. He then explained the working of the two vaccines and one by the Ahmedabad-based pharmaceutical firm Zydus Cadila.
Also read: DCGI’s Covaxin ‘approval’ is political jumla. It reinforces idea of Modi’s Atmanirbhar Bharat
How Covishield, Covaxin work
Gupta pointed out that the trials of the AstraZeneca vaccine, which makes use of chimpanzee adenovirus just like malaria and Ebola vaccines, were held across the world. Results of the trials were published in The Lancet last month and the data has been peer-reviewed, he added.
Data shows that the vaccine offers 70 per cent protection against Covid-19 and some “fluke” cases showed 90 per cent protection but that could have been because candidates in the group were younger, ThePrint’s Editor-in-Chief explained.
Bharat Biotech, on the other hand, does not have efficacy data out in the public yet, nor peer reviewed, Gupta said, adding that this has been pointed out by some eminent scientists like Dr Gagandeep Kang, the vice-chair of the board of Coalition for Epidemic Preparedness Innovations (CEPI).
Explaining how Covaxin works, Gupta said it uses a “dead virus” with an adjuvant that is usually alum, to raise a false alarm in a person’s body so that it prepares for an emergency. A person’s antigen presenting cells (APCs) engulf the dead virus, then go out and activate T cells and B cells that generate antibodies.
This route produces humoral immunogenicity, which means our body’s fluids also produce antibodies, making for a “robust reaction”, he explained. The Chinese vaccines developed by firms Sinopharm and Sinovac are also whole virus vaccines and like India, China has also hurriedly issued clearances for a vaccine, he added.
Also read: Why Bharat Biotech’s Covaxin is the object of national pride & scientific scepticism
Zydus Cadila’s vaccine follows DNA route
Unlike Pfizer and Moderna’s messenger RNA vaccines, Oxford University’s adenovirus-approved jab and whole virus vaccines developed by Bharat Biotech and Chinese firms, an Ahmedabad-based firm called Zydus Cadila is set to develop a plasmid DNA vaccine and recently got clearance for Phase 3 trials.
Following a nucleic acid route, the ZyCoV-D vaccine involves injecting some genetic code of Covid-19 into a person’s body, Gupta said. “When that happens, our body will transcribe the RNA say, of the spike protein, and then starts producing antibodies again,” he added.
The vaccine “smuggles” DNA from the virus into our body using plasmid, which is a small extra chromosomal DNA molecule that functions like an “empty wagon”, he explained.
If cleared, ZyCoV-D will be India’s second swadeshi vaccine. “[We should] celebrate the fact that India has such deep strength, not just in vaccine manufacturing, but also in vaccine research and design,” Gupta said.
Watch the full episode here: