Bharat Biotech’s Covaxin has demonstrated a potentially promising efficacy against Covid-19 but also significant immunogenicity against the rapidly emerging variants.
"Today is an important milestone in vaccine discovery, for science and our fight against coronavirus. With today's results from our Phase 3 clinical trials, we have now reported data on our Covid-19 vaccine from Phase 1, 2, and 3 trials involving around 27,000 participants," Bharat Biotech Chairman and Managing Director Krishna Ella said.
What does the ‘efficacy’ of a vaccine mean?
The efficacy of a vaccine is a way to understand how much the shot protects people against a virus or bacteria compared with if they would not have been vaccinated.
The vaccines ability to protest people inoculated is measured – The ability of the jab to protect the person from mild to severe symptoms to prevent you from getting infected with the disease.
In its Phase 3 clinical trials, Bharat Biotech will be involving 25,800 volunteers across India. It has also been focused on understanding Covaxin’s efficacy to prevent symptomatic, including severe symptomatic Covid-19 cases.
What does Covaxin’s data say?
As per the initial findings, the vaccine has an efficacy of 80.6 per cent. In simple terms, this means the vaccine was able to bring down the number of symptomatic Covid-19 cases by nearly 81 per cent in those vaccinated in the trial as compared to the group that received a placebo.
According to reports, the results were collected by studying 43 participants in the trial who had tested positive for Covid-19 two weeks after receiving their second dose and had presented with either mild, moderate or severe symptoms. The trials were unblinded at this point to check how many of these participants had received Covaxin and how many got a placebo.
The results depicted that 36 out of these 43 participants had received a placebo, while seven had received Covaxin.
These results have so far not been published in a scientific journal or peer-reviewed.
Why is this important?
Covaxin is being used massively in India’s vaccination programme against Covid-19. A higher efficacy would mean a higher chance of protecting the vulnerable population against the disease.
Covishield, the other vaccine being used in the government’s campaign, has an efficacy of around 53 per cent when the second dose is given less than six weeks after the first dose. As per the regulatory approval to Covishield so far, the second dose has to be given around 4-6 weeks after the first dose.