Covaxin 77.8% effective against symptomatic Covid-19: Bharat Biotech

Bharat Biotech says that the final efficacy analysis of Covaxin shows it to be 77.8 per cent effective against symptomatic Covid-19, through evaluation of 130 confirmed cases, with 24 observed in the vaccine group versus 106 in the placebo group. 

The company claimed Covaxin is the first to report promising efficacy against asymptomatic infections based on qPCR testing that will help in reducing disease transmission. 

This paves the way for Covaxin to get World Health Organisation's approval for its inclusion in the Emergency Use List of Covid-19 vaccines. 

The company added that the analysis demonstrates Covaxin to be 93.4 per cent effective against severe symptomatic Covid-19. The safety analysis demonstrates that adverse events reported were similar to placebo, with 12 per cent of the subjects experiencing commonly known side effects and less than 0.5 per cent of them feeling serious adverse effects. The efficacy data further demonstrates 63.6 per cent protection against asymptomatic Covid-19 and  65.2 per cent protection against the SARS-CoV-2, B.1.617.2 Delta variant . 

Phase 3 clinical trials of Covaxin were an event driven analysis of 130 symptomatic Covid-19 cases, reported at least two weeks after the second dose, conducted at 25 sites across India.

Covaxin is formulated with  Algel+IMDG adjuvant. IMDG is a TLR7/8 agonist known to induce memory T-cell responses along with strong neutralising antibodies, the company said. 

"The activation of cell mediated immune responses is especially valuable in a multi epitope vaccine such as Covaxin, where immune protection can be achieved from S, RBD and N proteins alike," it added. 

IMDG was developed under partnership between Virovax and NIAID, National Institutes of Health, US.

The  Data Safety Monitoring Board has not reported any safety concerns related to the vaccine.  The overall rate of adverse events observed in Covaxin was lower than that seen in other Covid-19 vaccines, Bharat Biotech claimed. 

Krishna Ella, Chairman & Managing Director, Bharat Biotech, said, “The successful safety and efficacy readouts of Covaxin as a result of conducting the largest ever Covid Vaccines trials in India establishes the ability of India and developing world countries to focus towards innovation and novel product development. We are proud to state that Innovation from India will now be available to protect global populations.” 

Balram Bhargava, Secretary Department of Health Research & Director General Indian Council of Medical Research, said, “I am delighted to note that Covaxin, developed by ICMR and BBIL under an effective public private partnership, has demonstrated an overall efficacy of 77.8% in India’s largest Covid phase 3 clinical trial thus far. Our scientists at ICMR and BBIL have worked tirelessly to deliver a truly effective vaccine of highest international standards. Covaxin will not only benefit the Indian citizens but would also immensely contribute to protect the global community against the deadly SARS-CoV-2 virus. I am also pleased to see that Covaxin works well against all variant strains of SARS-CoV-2. The successful development of Covaxin has consolidated the position of Indian academia and Industry in the global arena.”

Additional clinical trials to establish safety and efficacy in children between 2-18 years of age are on.  

A clinical trial to determine the safety and immunogenicity of a booster dose is also in process. "Several research activities are being carried out to study variants of concern and to assess their suitability for follow up booster doses," it said. 

Covaxin has been evaluated through neutralising antibody responses against several variants of concern, namely B.1.617.2 (Delta), B.1.617.1 (Kappa), B.1.1.7 (Alpha), B.1.351 (Beta), P2- B.1.1.28 (Gamma).