Expert panel gives nod to Covaxin for restricted use
Experts at India’s drug regulators recommended that the Oxford-AstraZeneca and Bharat Biotech coronavirus vaccines be allowed for use in India, the government said on Saturday, paving the way for a formal confirmation before which mass inoculations can begin in the world’s second-most populous country.
The endorsement by the Subject Expert Committee (SEC) of the candidate made by University of Oxford and British pharma firm AstraZeneca was communicated on Friday by officials who were aware of developments. This vaccine is being manufactured in India by Serum Institute of India, which will market it as Covishield.
The second endorsement, which carries additional conditions that the use may only be “in clinical trial mode” of the candidate by Hyderabad-based Bharat Biotech was unexpected since the developer is yet to determine efficacy data, and it was described as perplexing by independent experts.
The Bharat Biotech vaccine, known as Covaxin, is in phase III trials that began in mid-November. The SEC recommended it be given permission “for restricted use in emergency situation in public interest as an abundant precaution, in clinical trial mode, specially in the context of infection by mutant strains,” the ministry of health and family welfare said in a statement on Saturday.
Explaining what use in emergency situation means, a member of the expert panel, who did not wish to be named, said: “This pandemic is an emergency situation, and this vaccine has been allowed to be used in this situation for lack of any other alternatives before us to control the pandemic. One company alone will not be able to fulfil country’s requirement as India is a vast country so Covaxin is the only another option right now.”
“Clinical trial mode would mean the data that is there currently is not sufficient for it to be called a full-fledged therapy. It’s working more on an experimental basis,” this person added.
It appears that the roll-out of the Bharat Biotech vaccine will more restricted than the Serum Institute of India-manufactured vaccine, which has an efficacy rate of 62%.
“Serum Institute’s vaccine will be the main vaccine. Bharat Biotech’s vaccine is a backup for emergency situation, which may happen if there is a sudden surge in cases or reinfection,” Dr Randeep Guleria, AIIMS director, told NDTV.
Dr Gagandeep Kang, professor in the department of Gastrointestinal Sciences at Christian Medical College (CMC), Vellore, and one of the country’s topmost vaccine experts said: “We actually do not have EUA (emergency use authorisations), so I have no clue what the language in the statement today means, except that it is different for Covishield and Covaxin.”
The recommendations by the SEC have been sent to the Drugs Controller General of India Dr VG Somani, who heads India’s drug regulator Central Drugs Standards and Control Organisation (CDSCO).
“The approval is confirmed. It’s now a mere formality for the national drugs controller to put out an order,” said a senior health ministry official, who asked not to be named.
The DCGI’s final grant could put India among a handful of countries, including the US and UK, that have begun vaccinations. Both the US and the UK too have approved two vaccines, but in their case, all of the candidates have completed requisite scientific process.
So far, the Oxford-AstraZeneca candidate – globally known as AZD1222 – remains India’s strongest contender to facilitate immunisation of tens of thousands of people. SII officials have said in recent weeks that they may have 40-50 million doses ready for shipping across India shortly.
Termed as the “vaccine of the world”, the Oxford antidote is easier to store and transport than the vaccines approved in other western countries. It can be kept at refrigerator temperatures (between 2-8°C) for up to six months, a feature that facilitates utilisation of India’s vast immunisation infrastructure.
Like the Oxford vaccine, Bharat Biotech’s Covaxin is also easy to store and transport, and is being indigenously produced. The company is aiming to produce up to 300 million doses annually, and it did not disclose if it has stockpiled any volumes.
“Bharat Biotech has announced successful recruitment of 23,000 volunteers, and continued progress towards achieving the goal of 26,000 participants for Phase-3 clinical trial of Covaxin across multiple sites in India. The clinical trials... is India’s first and only Phase III efficacy study for a Covid-19 vaccine, and the largest phase III efficacy trial ever conducted for any vaccine in India. Covaxin has been evaluated in approximately 1,000 subjects in Phase I and Phase II clinical trials, with promising safety and immunogenicity results, with acceptance in international peer reviewed scientific journals,” the company said in a statement on Saturday.
In December, the company released data from phase I/II trials showing most volunteers who were given the dose developed antibodies and these were comparable to antibodies developed after a natural infection.
Efficacy data, which the company has said in its protocol will be analysed at 130 infections, is yet to be announced. Developers calculate efficacy when they hit the preset number of infections, at which point they ‘un-blind’ the trial to check how many of these were in people who actually got the vaccine (as compared to a placebo).
If the number of infections among those vaccinated is at least 50% fewer, the vaccine is deemed to have an efficacy rate of 50% -- the minimum bar any coronavirus vaccine needs to meet for approval.
Covishield, based on an adenovirus vector, has shown an efficacy rate of 62% in trials held in UK and Brazil.
The Bharat Biotech vaccine is based on an inactivated virus platform, one of the oldest known methods to develop an inoculation. This technique has been used historically for several other diseases including Hepatitis A, Influenza, Polio and Rabies.
The country is also gearing up to carry out the world’s largest vaccination programme, with all states and Union territories conducting mock inoculation drills in a test run ahead of the launch.
Union health minister Harsh Vardhan on Saturday announced that shots administered in the first phase of India’s inoculation drive will be free of cost. The government aims to vaccinate 300 million people in the high-risk category of the population by July-August in this phase.
The SEC on Saturday also granted permission to Ahmedabad-based Zydus Cadila to conduct Phase 3 trials of its vaccine candidate.