`Covaxin' overall 77.8% effective': Here are Bharat Biotech's Phase III trial results

Sharing the final phase-3 pre-print data on medRxiv, the company has claimed that its vaccine demonstrates overall efficacy of 77.8 percent against symptomatic infection.

"Efficacy analysis demonstrates Covaxin to be 77.8 percent effective against symptomatic COVID-19, through evaluation of 130 confirmed cases, with 24 observed in the vaccine group versus 106 in the placebo group," said the company.

The company said that efficacy analysis demonstrates that Covaxin to be 93.4% effective against severe symptomatic COVID-19. Safety analysis demonstrates adverse events reported were similar to placebo, with 12 percent of subjects experiencing commonly known side effects and less than 0.5 percent of subjects feeling serious adverse events.

Efficacy data demonstrates 63.6 percent protection against asymptomatic COVID-19 and efficacy data demonstrates 65.2 percent protection against the Covid19 Delta variant.

Phase 3 clinical trials of Covaxin was an event-driven analysis of 130 symptomatic COVID-19 cases, reported at least two weeks after the 2nd dose, conducted at 25 sites across India. Covaxin is formulated with a novel Algel+IMDG adjuvant.

IMDG is a TLR7/8 agonist known to induce memory T cell responses along with strong neutralizing antibodies. 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. IMDG was developed under a partnership between Virovax and NIAID, National Institutes of Health USA.

Covaxin was well tolerated and 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.

The safety profile of Covaxin is now well established based on inactivated vaccines technology, and in large part due to the extensive 20-year safety track record of Bharat Biotech's vero cell manufacturing platform. Furthermore, Bharat Biotech has so far not sought indemnity for Covaxin from the governments.

The company also said that no licensed SARS-CoV-2 vaccine has reported efficacy against asymptomatic infection in a randomized controlled trial based on qPCR testing. COVAXIN® is the first to report promising efficacy against asymptomatic infections based on qPCR testing that will help in reducing disease transmission.

"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," said Dr. Krishna Ella, Chairman & Managing Director, Bharat Biotech.

The company also mentioned that Covaxin has been specifically designed to meet the needs of global distribution chains, the requirements for which are more critical in low- and middle-income countries. It has been formulated to enable shipping and long-term storage at 2-8ºC. It is also formulated to adhere to a multi-dose vial policy, thereby reducing open vial wastage, saving money to procurement agencies and governments alike.

"Our scientists at ICMR and BBIL have worked tirelessly to deliver a truly effective vaccine of the highest international standards. Covaxin will not only benefit the Indian citizens but would also immensely contribute to protecting 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," said Prof. (Dr) Balram Bhargava, Secretary Department of Health Research & Director General Indian Council of Medical Research(ICMR).

Bharat Biotech also said that its commitment to continuous improvement of Covaxin is well underway with additional clinical trials to establish safety and efficacy in children between 2-18 years of age. 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.

Covaxin has also been evaluated through neutralizing 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).

"The overall efficacy of 77.8 % following the phase III clinical trial of Covaxin is wonderful news. ICMR-NIV and BBIL have had very fruitful interactions during this exhilarating journey. Sera from Covaxin recipients have also been evaluated against viral variants detected in India i.e., the Alpha, Beta, Zeta, Kappa, and Delta. The making of this vaccine entirely on Indian soil is a matter of great pride to every Indian," said Prof Priya Abraham, Director National Institute of Virology, ICMR.

Covaxin has now received emergency use authorizations in 16 countries including, Brazil, India, Philippines, Iran, Mexico, etc. with EUA's in process in 50 countries worldwide. The company is in discussions with WHO to obtain emergency Use Listing for Covaxin. The product has been exported to several countries with additional requests for supplies being received.

Bharat Biotech has established Covaxin manufacturing at 4 facilities within India, further expansions are in process to reach an annualized capacity of 1 billion doses by the end of 2021. Technology transfer activities are in progress to companies in the United States and other countries.