Phase III trial data showed vaccine efficacy of 93.4% and 63.6% against severe Covid-19 and asymptomatic disease, respectively.
Indian firm Bharat Biotech has reported safety and efficacy analysis data from the Phase III clinical trial of its Covid-19 vaccine, COVAXIN, which showed an efficacy of 77.8% against mild, moderate and severe Covid-19.
Against severe symptomatic Covid-19 alone, the vaccine efficacy was found to be 93.4%.
Developed in alliance with the Indian Council of Medical Research and National Institute of Virology Pune, COVAXIN is a whole virion inactivated vaccine formulated with a new Algel plus IMDG adjuvant.
The Phase III trial had 25,798 subjects aged between 18 to 98 years enrolled across 25 sites in India.
The first occurrence of Polymerase Chain Reaction (PCR) confirmed mild, moderate or severe Covid-19 with onset at a minimum of 14 days following administration of the second dose was the trial’s primary goal.
Bharat Biotech noted that the Phase III trial of the vaccine was an event-driven analysis of 130 symptomatic Covid-19 cases, reported at least two weeks from the second dose.
In the trial, 24 Covid-19 cases were noted in the vaccine arm compared to 106 in the placebo arm.
Data showed that COVAXIN was found to be well-tolerated with the Data Safety Monitoring Board not reporting any safety concerns linked to the vaccine.
Vaccine efficacy of 63.6% against asymptomatic Covid-19 was also noted in the trial.
Furthermore, participants receiving the vaccine had increased protection against emerging B.1.617.2 (Delta) and B.1.351 (Beta) variants of SARS-CoV-2 as against people who earlier had natural infections.
The vaccine’s efficacy rate was 65.2% against these variants.
In addition, the overall rate of adverse events related to COVAXIN was lesser than that observed in other Covid-19 vaccines, Bharat Biotech said.
Bharat Biotech chairman and managing director Dr Krishna Ella 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.”
In December last year, Bharat Biotech and Ocugen signed a binding letter of intent to co-develop COVAXIN for the US market.
Currently, Bharat Biotech is conducting clinical trials to assess the safety and efficacy of COVAXIN in children aged two to 18 years.
Another trial evaluating the safety and immunogenicity of a booster dose of the vaccine is progressing.