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Covid 19 Vaccine

09 January, 2021 - By Bhanu

This allows the vaccines to be offered to healthcare workers and frontline workers in India; Neither Covishield nor Covaxin has completed a crucial phase-3 trial in India.

Vaccines by Bharat Biotech and Serum Institute of India (SII) were formally approved by the Central Drugs and Standards Committee (CDSCO) on Sunday.

This allows the vaccines — Covishield from SII and based on the Oxford AstraZeneca vaccine, and Covaxin from by Bharat Biotech — to be offered to healthcare workers and frontline workers in India. The Health Ministry has said 3 crore such personnel, considered at highest risk for COVID-19, will be given the vaccine for free. It isn’t yet known which vaccine will be made available to these personnel though multiple officials say rollouts can begin in less than a fortnight.

Neither Covishield nor Covaxin has completed a crucial phase-3 trial, under which a vaccine candidate is administered to volunteers at multiple locations across the country, in India. The CDSCO approval was based on a recommendation by a Subject Expert Committee of technical experts who deliberated for two days in sessions lasting over 12 hours on approvals to the two vaccines.

The minutes of the SEC meeting aren’t yet available. However, a press statement by the Health Ministry said the vaccine’s efficacy in Indian volunteers was “comparable” to that tested in overseas trials.

Both the approvals accorded are for “restricted use in emergency situation” and in the case of Bharat Biotech the approval wording notes it is in “..public interest as an abundant precaution, in clinical trial mode, to have more options for vaccinations, especially in case of infection by mutant strains.” What these conditions are were not specified.

Bharat Biotech whose vaccine candidate was being tested in large phase-3 efficacy trial in India, has provided safety and immunogenicity data — proof that the inoculation doesn’t harm and is capable of stimulating an immune response in the body — but no efficacy data, that shows the vaccine achieves its primarily goal of protecting against disease. Doing such a trial would have, according to the company’s timeline, taken some more months.

Head of the CDSCO V.G. Somani, read out a prepared statement according approval and on the sidelines of the briefing told reporters that the vaccine was “110% safe” and that every adverse event, were they to happen, would be diligently followed up.

Samiran Panda, Head of the epidemiology and communicable diseases division, ICMR, defended the emergency approval to the Covaxin on the ground that the existence of the pandemic, the detection of the UK strain and the vaccine’s safety profile meant that it could approved in ‘clinical trial mode.’

“This isn’t the standard approval given to a vaccine. The scheduled trial (on 26,000) will continue and every person who gets the vaccine will be followed up and monitored for risk as well as benefit. It can also be withdrawn. This vaccine, as of now is not for everybody, and is being given under restricted use condition,” he said.

Covaxin has been developed based on a inactivated Sars-CoV-2 strain cultured at the National Institute of Virology, an ICMR body. Because it was a whole virus (and therefore, more of it would be exposed to the immune system) the chances that it would mount a response against a variety of mutant virus types or strains were higher.

“I would say scientifically Covaxin offers much better antigen presentation (and a consequent immune response) than a vaccine developed as a specific part of the(viral) protein,” Dr Panda told The Hindu. “So this is potentially more effective against mutant strains.” 

Historically there was evidence for this from polio vaccines. An interim analysis of the vaccine’s efficacy would happen around March, said Dr. Panda.

Randeep Guleria, Director, All India Institute of Medical Sciences to referred to the Bharat Biotech vaccine as a “backup vaccine” and to be used if it was not clear how efficacious the SSI vaccine would be.

A medical doctor-cum-research head of a lab, affiliated to a government research lab, also expressed reservations. “At this point, I wouldn’t advise Covaxin. All we seem to know is that it’s safe and so may not be harmful but efficacy is a different matter and needs to be proved,” the expert said requesting anonymity.

Independent activists too expressed concern over a “hasty” approval. 

“In the interest of transparency, we ask that the regulator share detailed rationale or the decision along with disclosure of data... We are baffled to understand what scientific logic has motivated top experts in the SEC to approve this vaccine (Covaxin) post haste,” Malini Aisola, of the All India Drug Action Network, said in a statement.