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Covaxin: Scientists Fear Inefficacy of Vaccine If Released by August 15

GUWAHATI: The Indian Council of Medical Research (ICMR) conceived the possibility of the launch of a COVID vaccine – Covaxin - for the public latest by August 15 this year. Developed by Hyderabad’s Bharat Bio-tech, the developer has received clearance from Drug Controller General of India (DGCI). Although the launch of such a vaccine is the need of the hour, the announcement has drawn a lot of criticism from the scientific community. 

ICMR’s letter to participants:

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On July 2, ICMR’s director-general, Balram Bhargava, wrote a letter to the 12 institutions participating in the trial to “fast-track all approvals.” All participants on whom the vaccine would be tested should be enrolled “no later than July 7.” “Non-compliance will be viewed very seriously,” warned the letter adding that the vaccine was “the top-most priority” of the government at the moment.

Criticism by researchers on the August 15 deadline:

The hasty deadline, some believe, could lead to compromise in the quality of the COVID vaccine with the developers themselves calling it a challenging task.

“It will be a very challenging and difficult task considering that we have to look at both efficacy and safety of any vaccine that is introduced. Also, if we get the desired results, the other challenge is the process of mass production of the vaccine,” said AIIMS Director Randeep Guleria, head of the clinical research group of the national task force on COVID-19, to national media who himself was left surprised at the announcement.

“As a principal investigator, I would not move unless I get a clearance, let it be anyone who is telling. It is not that I am being adamant, but I am humbly saying that we should follow the principles. And the first and the most important principle is: do no harm.” said Venkata Rao, talking to national media. Rao is in charge of the trial at the Institute of Medical Sciences and SUM Hospital in Odisha, which is one of the 12 chosen sites.

The fast approaching deadline is much earlier than the vaccine developer’s own estimate and their timeline provided to the regulatory body, Drug Controller General of India. The approval for clinical trials had been given to the developer on June 29, and not even the company believes that the vaccine will be ready by August 15.

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3-Phased Trials:

The vaccine developer, Bharat Biotech, said that the results of Phase I and Phase II trials would be out only by October. Based on the success results of Phase I and Phase II, they would be able to progress to larger clinical trials only after which the licensure timelines are set out upon receiving regulatory approvals.

Phase I: Phase I trials check safety of the vaccine in the body and are usually carried out on a few dozen volunteers and take a few months. 

Phase II: In Phase II trials, scientists check whether the vaccine is triggering the desired immune response. Hundreds of volunteers are required for this phase of trials and this too could take up to several months. 

Phase III: The Phase III trials are larger clinical trials and the company has only cleared two phases so far.

As per the information posted in the Clinical Trials Registry, the official online depository of all clinical trials in India, the duration of Covaxin is mentioned as 15 months. In addition, Phase I and Phase II trials are yet to be approved by the institutional ethics committees of six of the 12 selected hospitals which is a mandatory requirement before the trial begins. 

It is impossible that all three stages can be completed before August 15 as scientists believe that Phase-III trials are being skipped.

Why does the government think that the vaccine will work?

Clinical trial data determines whether a vaccine works or not. Inactivated vaccines used against SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndromme) had led to poorly regulated inflammatory responses or cytokine storms where the immune system overreacts.

Many vaccine companies have been adopting other safer approaches but an inactivated vaccine requires booster doses because they offer protection for only a limited period.

The data coming from animal and early human studies from Chinese vaccine companies that developed inactivated vaccines have been promising. It is said that this data may have given the government confidence to fast-track the vaccine development programme.

Bharat Bio-tech:

Bharat Biotech’s chairman and managing director, Dr Krishna Ella, on July 3, had told media persons that the company, which is the first Indian firm to have received approval to begin human trials of its COVID-19 vaccine candidate, had developed the first version of the vaccine within 40 days, after which the pre-clinical trials began. 

Bharat Biotech had built India's biggest BSL-3 high-containment facility for manufacturing inactivated polio vaccine, which will now be used for COVID-19 vaccine. BSL-3 is appropriate for work involving microbes that can cause serious and potentially lethal diseases via the inhalation route. 

Experts say that an inactivated vaccine involving live SARS-CoV-2 should be produced only in a BSL-3 containment facility due to a high risk of contamination or inadvertent release. 

ICMR has been working closely with Bharat Biotech for years. It had earlier partnered with Bharat Biotech for Rotavirus and H1N1 – Swine Flu vaccines.


Inputs from: Indian Express, Money Control and Scroll.in

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