COVID-19 vaccines in India: Bharat Biotech's Covaxin phase-3 trial crosses half-way mark

Hyderabad-based Bharat Biotech began phase-3 human clinical trials of its COVID-19 vaccine, called Covaxin, in mid-November targeting 26,000 volunteers. So far, 13,000 volunteers have received the vaccine across the country, the company said.

Six COVID-19 vaccines are in various stages of clinical trials in India, of which four are being indigenously developed in the country. Hyderabad-based Bharat Biotech is currently conducting phase-3 trails of its COVID-19 vaccine, called Covaxin, across multiple sites in India. The company announced Tuesday that the Covaxin Phase-3 trial has crossed 13,000 subjects - the half-way mark.

The phase-1 and 2 clinical trials of Covaxin, the indigenously developed Covid-19 vaccine, have shown promising safety and immunogenicity results. The vaccine was evaluated in approximately 1,000 subjects in the first two phases, the results of which were accepted by international peer-reviewed scientific journals, Bharat Biotech said in a statement issued on Tuesday.

The phase-3 human clinical trials began mid-November targeting 26,000 volunteers across India. The company claimed that "this is India's first and only Phase-3 efficacy study for a Covid-19 vaccine, and the largest phase -3 efficacy trial ever conducted for any vaccine in India."

"This is an unprecedented vaccine trial ever to take place in India, and we are overwhelmed with the steady rise in participation. We sincerely thank all the 13,000 volunteers across the country for their support in enabling us to bring out a safe and efficacious Indian vaccine for COVID-19. This pro-vaccine public health volunteerism is a morale booster for us to achieve our milestone target of 26,000 soon Thank you volunteers. Thank you India," Suchitra Ella, Joint Managing Director of Bharat Biotech, said in the statement.

EUA clearance for Covaxin still pending with DCGI

Bharat Biotech has developed the vaccine in collaboration with the Indian Council of Medical Research (ICMR) and National Institute of Virology (NIV). It is developed and manufactured in Bharat Biotech's BSL-3 (Bio-Safety Level 3) bio-containment facility located in Genome Valley, Hyderabad, the only one of its kind in the world.

Covaxin is a highly purified and inactivated two-dose Sars-CoV-2 vaccine manufactured in a Vero cell manufacturing platform with an excellent safety track record of at least 300 million doses, the company said.

Bharat Biotech applied for Emergency Use Authorisation (EUA) for its potential Covid-19 vaccine candidate on December 7. However, its application for EUA clearance for Covaxin is still pending with the national drugs regulator, Drugs Controller General of India (DCGI), for lack of adequate safety and efficacy data. An expert committee of the Central Drugs Standard Control Organisation (CDSCO) has sought additional safety and efficacy data from the company on the clinical trials carried out so far.

Pfizer and Serum Institute of India (SII) have also applied for emergency use approval for their COVID-19 vaccines in the country.

Trials on for 3 other indigenously developed COVID-19 vaccines

Three other indigenously developed COVID-19 vaccines are under clinical trails in India. While the one developed by Zydus Cadila is in phase-2 clinical trial, the vaccine candidate of Biological E is in it phase-1 clinical trials and Pune-based Gennova Biopharmaceuticals has also got conditional permission for phases 1 and 2 human clinical trial of its COVID-19 vaccine.

Serum Institute of India is also conducting phase 2 and 3 clinical trials of the Oxford-Astrazeneca vaccine in India. The Pune-based vaccine maker is also collaborating with American vaccine developer, Novavax, for the development and commercial collaboration of their Covid-19 vaccine candidate in India. A few days ago, the Institute presented their proposal before the government's subject expert committee (SEC) to seek permission for conducting the phase 3 trials of Novavax's vaccine candidate NVX-CoV2373. The SEC, however, recommended the company to revise the protocol.

Dr Reddy's Laboratories is conducting phase 2 and 3 clinical trials for Russian vaccine Sputnik V. The phase-II results of Sputnik V are expected in early January, a spokesperson for the Hyderabad-based company recently told a leading newspaper. The company plans to complete phase-III trials in March.