India’s first indigenously produced Covid-19 vaccine, Covaxin, has shown an interim efficacy of 81% in Phase III trials for preventing the virus. Covaxin has been developed in India jointly by the Indian Council of Medical Research (ICMR) along with Bharat Biotech International Limited (BBIL).        

The Phase III trial was initiated by ICMR and BBIL in mid-November 2020 and it was conducted on a total of 25,800 individuals across 21 sites. The interim efficacy of 81%, analyzed as per the protocol approved by the Drugs Controller General of India (DCGI), puts it at par with other global front-runner vaccines.

The initial interim analysis of Phase III trial data is based on 43 cases of Covid-19 of which 36 cases of Covid-19 were observed in the placebo group and 7 cases observed in the Covaxin group resulting in a point estimate of vaccine efficacy of 80.6 percent.

Bharat Biotech expects to get a clearer picture of its efficacy once 130 cases are accumulated among its participants. Phase 1 and Phase 2 clinical trials were conducted on 755 participants and demonstrated high safety profile of the candidate vaccine with seroconversion rates of 98.3% and 81.1% on day 56 and 104 respectively.

The results have been evaluated by an independent data safety and monitoring board show that the vaccine is well-tolerated and efficacious against SARS-CoV-2 across a wide range of age groups and variants in the country.

In March 2020, following the successful isolation of the SARS CoV-2 virus at ICMR-National Institute of Virology (NIV), ICMR entered into a public-private partnership with BBIL to develop the virus isolate into an effective vaccine candidate. ICMR-NIV characterized the vaccine developed by BBIL through in-vitro experiments and electron microscopy studies. Pre-clinical studies in small animals and hamsters showed promising results for safety and immunogenicity. Further studies conducted in rhesus macaques also established remarkable safety and protective efficacy of Covaxin.

“Covaxin has been developed on WHO prequalified vero cell platform globally recognized with a well-established track record of safety. Covaxin’s ability to neutralize UK variant strain of SARS-CoV-2 has also recently been established,” the ICMR said in its statement.

“The bench-to-bedside journey of completely indigenous Covid-19 vaccine in less than 8 months’ time showcases immense strength of Atmanirbhar Bharat [self-reliant India] to fight the odds and stand tall in the global public health community. It is also a testament to India’s emergence as a global vaccine superpower,” said Dr. Balram Bhargava, director general, ICMR.

“Covaxin demonstrated 81 percent interim efficacy in preventing Covid-19 in those without prior infection after the second dose. Data from 25,800 participants who received a vaccine or placebo in a 1:1 ratio showed that the vaccine candidate was well tolerated,” BBL said in its statement.

According to the Hyderabad-based vaccine maker, inclusion of the Algel-IMDG adjuvant in the vaccine enhances T-cell immune responses to Covid-19 leading to long-term protection. The vaccine has been approved for restricted emergency use under clinical trial mode and will have to be taken in two doses 28 days apart.

“With today’s results from our Phase 3 trials we have now reported data on our Covid-19 vaccine from Phase 1, 2 and 3 trials involving around 27,000 participants. Covaxin also demonstrates significant immunogenicity against the rapidly emerging variants,” said Dr Krishna Ella, chairman and manging director, Bharat Biotech.

Covaxin Timeline:
March 11, 2020: Covid-19 was declared a pandemic by the WHO. India joined the global race of developing safe and effective vaccines to protect its citizens as well as the global community from this dreaded disease.
• March 13, 2020: ICMR-National Institute of Virology (ICMR-NIV) successfully isolates the SARSCoV-2 virus. India becomes the 5th country in the world to achieve this feat.
• April 2020: ICMR enters into a public-private partnership with Bharat Biotech International Ltd (BBIL) for developing an effective vaccine candidate for SARS-CoV-2.
• May 2020: ICMR-NIV transfers the virus strain to BBIL and characterizes the vaccine developed by BBIL through in-vitro experiments and electron microscopy studies.
• June-August 2020: Experiments in small animals (mouse, rats and rabbits) and hamsters established promising safety and immunogenicity of COVAXIN. Data has been published by the highly reputed journal of the Cell Press.
• July-August 2020: Studies conducted in rhesus macaques established safety and protective efficacy of Covaxin. Results established the remarkable ability of the vaccine candidate to clear the virus from infected organs along with its capacity to mount B and T cell immune response.
• July-October 2020: Phase 1 and 2 clinical trials conducted in 755 participants demonstrated a high safety profile of the candidate vaccine along with seroconversion rates of 98.3% and 81.1% respectively on day 56 and 104 respectively. The results are published in Lancet's journal.
• November 2020: The largest ever clinical trial for COVID-19 in India launched for the third phase with over 25,800 participants
• January 3, 2021: DCGI grants approval for restricted use in emergency situations for COVAXIN
• January 16, 2021: India rolls-out phase-wise COVID-19 vaccine administration starting with healthcare and frontline workers
• January 27, 2021: COVAXIN’s ability to neutralize UK variant strain of SARS-CoV-2 established and published in Journal of Travel Medicine.
• March 3, 2021: Interim results of Phase 3 efficacy trials of COVAXIN show 81% efficacy against SARS-CoV-2virus. The follow-up of participants in the trial are still ongoing.