New Delhi: Bharat Biotech’s Covaxin is more likely to act against the mutant Covid-19 strain as it is based on the whole virus rather than targeting some parts of it, Indian Council of Medical Research (ICMR) Director General Dr Balram Bhargava has said.
In an interview to ThePrint, Bhargava stated that this was one of the considerations for giving it a conditional nod even though there is no clear data available for the efficacy of the vaccine.
“We know that the virus has undergone mutations including in the spike protein. Pfizer has said that they will need six weeks to modify the vaccine. But because Covaxin is basically the whole virus killed, it is more likely to act against the mutant strain too,” he said.
“Simply put, if there are say 1,000 points in a vaccine, of which two have mutated, this is still going to have 998 points to generate a response, unlike others such as mRNA vaccines, which target specific areas and may not work as well when those areas mutate,” he added.
This, he added, was one of the considerations for the government drug regulator’s subject expert committee (SEC) as it recommended conditional approval for the vaccine. The vaccine was Sunday approved by the Drugs Controller General of India (DCGI) for emergency use, along with Oxford-AstraZeneca’s Covid-19 vaccine Covishield.
The ICMR chief expressed hope that the vaccine would start being procured soon for the national immunisation programme. “This is a great day for Indian science, India and low- and middle-income countries in general. Once we start using it, they can too,” he said.
Bhargava, however, added that he was not aware of any decision to allow export of the vaccine just yet or on when it would be available in the open market.
Bhargava’s remarks come as questions have been raised about the approval granted to Covaxin in the absence of efficacy data.
No Phase 3 efficacy data available
Covaxin is a collaborative effort between the ICMR and Bharat Biotech, which means that India will have an indigenous vaccine in the Covid-19 vaccination programme right from the start. The virus on which the pharmaceutical company developed the vaccine was isolated early on at the National Institute of Virology in Pune.
Asked if there is any data on how efficacious Covaxin is against the SARS-CoV-2 virus, mutated or otherwise, Bhargava said: “They do not have a figure yet. But they have submitted efficacy data in rats, mice, monkeys. There is also some efficacy data from the phase I and II trials, and you can extrapolate from there.
“Moreover in phase III it has been administered to 22,000 subjects and has been found to be extremely safe. The SEC has met for 6-7 hours each for two days and they have gone into all aspects.”
For both Covaxin and Covishield, Bhargava added, the trials would continue, as would rolling reviews.
“As I have been repeatedly saying for all of last year, we have been consistently ahead of the (Covid) curve. This is a very good proactive and preemptive move by the Government of India and a victory of Indian science. We have now also successfully cultured the mutant virus strain in ICMR,” he added.
Covaxin has been having trouble recruiting volunteers for phase III trials.
In a statement late Saturday night, Suchitra Ella, Joint Managing Director of Bharat Biotech, said, “We thank every volunteer who has taken the time to participate in this trial. Their volunteering spirit is a great morale boost for India and the world. We thank all the principal investigators, doctors, medical staff & the hospitals for their cooperation & support in taking the phase 3 trials forward in 26,000 volunteers in India. We continue our progress towards achieving the goal of 26,000 participants for Phase-3 clinical trials of Covaxin.”
Questions are already being asked
The approval for Covaxin, however, has already led to expressions of concern.
The All India Drug Action Network (AIDAN), a network of several NGOs working in the field of healthcare, said it was “shocked to learn of the SEC’s recommendation to grant REU (restricted emergency-use) approval”.
“Disturbingly, it appears that no efficacy data for the vaccine candidate were submitted from the phase 3 trials that are ongoing and are being conducted by Bharat Biotech and ICMR. The only data for humans, available through publication pre-prints, are of safety and immunogenicity from Phase 1 and Phase 2 trials across a total of 755 participants,” it added in a statement.
Demanding that the trial data be made public, the AIDAN also questioned the claim that the vaccine would work against the mutant strain as there is no such scientific data in the public domain.
It asked for the approval to be reconsidered.
On Covisheld, too, the AIDAN asked for clarity on the dosing schedule that has been approved and the efficacy estimates for that.
An earlier version of the report erroneously stated that the hope of Covaxin’s potential against the mutant strain doesn’t find a mention in the official DCGI statement. The report has been updated to correct the error.