As of 24 January 2021, some 16 lakh healthcare workers in India have been vaccinated under the national COVID-19 vaccination drive. The vaccination campaign isn't yet open to the general population. However, more people are being invited to get vaccinated against SARS-CoV-2 by the day, and many questions still linger about vaccination, and the utility of the vaccines approved for emergency-use in India, in preventing COVID-19 disease in those who have been immunised.
Bharat Biotech's Covaxin and Serum Institute of India's Covishield are the only two vaccines with approval for emergency-use in India. The clinical trial process for these vaccines were fast tracked, cutting years from the testing and observation phases of the trial. Does this compromise the safety of these vaccines?
Vaccines that clear mandatory checks, clinical trials are safe
Experts point out that the data from fast tracked trials goes through rigorous scrutiny by regulators and the scientific community.
"Both [Covaxin and Covishield] cleared the safety aspects of the trial, by clearing Phase 1 and Phase 2. They have also been given to large numbers of people in Phase 3, and have not shown any significant safety issues," said Dr Shahid Jameel, CEO of the Wellcome Trust/DBT India Alliance and Director of the Trivedi School of Biosciences at Ashoka University.
Testing of the vaccines being fast tracked doesn't compromise the scientific scrutiny of the data from these trials, by regulators and the scientific community, experts said.
"The vaccine is made after a lot of scientific scrutiny, and goes through regulatory processes and approvals from the government of the day, in various countries. There may be side effects. That is likely to happen anyway, at any stage, and anywhere in the world. Don't let that dissuade you from taking the vaccine," Dr Om Srivastava, director of infectious diseases at Jaslok Hospital, Mumbai, advised.
"Both the COVID-19 vaccines being manufactured in India are being tested and manufactured indigenously, and we're well aware of the fabric of the companies manufacturing it," Dr Srivastava added. "I think that, in itself, should be sufficient to inspire confidence in the vaccine maker's pro forma."
Experts also agree that any conclusions can only be made once the highly-anticipated efficacy data from Phase 2 and Phase 3 trials of both vaccines, are released publicly.
"What is yet to be done is clarifying efficacy, the data for which is not yet available in India for either vaccine," said Dr Jameel.
"We'll definitely know more in six months to a year's time," Dr Srivastava agreed.
The Covishield vaccine is at a slight advantage in this regard " it is backed by efficacy data from other countries, which show that is over 90 percent effective in preventing COVID-19 disease. The indigenous Bharat Biotech Covaxin, on the other hand, is being tested for the first time, and has safety data but no peer-reviewed study to back its effectiveness in preventing COVID-19 disease.