Phase 3 clinical trial data shows Bharat Biotech’s Covaxin has 77.8 percent efficacy
The data will be reviewed by the WHO on 23 June in a ‘pre-submission meeting’, and COVAXIN will be allowed for export to other countries only after an approval from the global health body
The indigenously developed COVID-19 vaccine COVAXIN has an efficacy of 77.8 percent as per phase three clinical trials data submitted to the Drugs Controller of India, CNN-News18 reported.
The vaccine, which is manufactured by the Hyderabad-based biotech company Bharat Biotech, was developed by the Indian Council of Medical Research and the National Institute of Virology (NIV), Pune.
The data from trials, conducted by Bharat Biotech among 25,800 participants, however, is yet to be published in an internationally recognised, peer-reviewed journal.
What is vaccine efficacy?
Vaccine efficacy has been defined by the World Health Organisation as the percentage reduction in disease incidence in a vaccinated group compared to an unvaccinated group under optimal conditions.
For example, Pfizer/BioNTech reported efficacy of 95 percent for its COVID-19 vaccine. This means a 95 percent reduction in new cases of the disease in the vaccine group compared with the placebo group.
What the efficacy data entails?
Bharat Biotech had revealed “interim analysis” data twice in the past. The first “interim analysis” of Phase III results, presented in March, indicated COVAXIN was 81 percent effective in preventing COVID-19 in those without prior infection after the second dose.
Data also showed a 100 percent reduction in chances of hospitalisation in case of infection.
The second “interim analysis” released in April 2021 showed COVAXIN’s efficacy against COVID-19 at 78 percent.
Controversies surrounding COVAXIN
The COVID-19 vaccine was approved for “restricted use in emergency situations” after Phase 1 and 2 trials. The All India Drug Action Network had said that it was “baffled to understand the scientific logic” to approve “an incompletely studied vaccine”. COVAXIN was made by the National Institute of Virology by isolating an Indian strain of the virus.
In April, Brazil’s health regulator rejected an application to give the Bharat Biotech vaccine certificate of Good Manufacturing Practices following an inspection of the company’s site in Hyderabad earlier this month, according to The Indian Express.
The company had also last month said that the Rs 150 per dose cap on its price decided by the Centre was “not sustainable in the long run”, and a differential price in the private markets was justified to “offset parts of the costs”.
Soon after, a shortage of doses had led to the shutting down of over 300 centres giving COVAXIN doses in Delhi.
Moreover, in a setback to those given the COVAXIN jab and planning travel to Dubai, the UAE said only travellers who have received two doses of a UAE-approved vaccine will be allowed in the country.
Emirate authorities have listed Covishield and Sputnik-V in the list of approved vaccines for travellers. Bharat Biotech was also denied emergency use of its vaccines by the US Food and Drugs Administration on 11 June.
The EUL is also a prerequisite for a vaccine to be a part of Covax, the global vaccine sharing initiative. But COVAXIN is not on that list yet, causing worry among those planning to travel abroad for work or study.
This WHO EUL assumes significance also because many countries are now using it as a benchmark for allowing vaccinated foreign nationals to travel.
Bharat Biotech was also issued a notice, along with the Centre, by the Delhi High Court challenging the permission granted to the company to conduct trials of COVAXIN, on children aged two to 18.
Other COVID-19 vaccines and their efficacy
Covishield, the Astra Zeneca vaccine being produced by Pune’s Serum Institute of India, was found to have an efficacy of 70.42 percent, the ICMR had said after the Phase III clinical trials.
Meanwhile, the efficacy of Russia Sputnik V vaccine stands at 92 percent and the same figure for Moderna’s mRNA vaccine is 90 percent.
As per clinical trials, the Pfizer vaccine is 60 to 70 percent effective against variants of concern.
India is also preparing to use a local version of the Novavax vaccine, which will be produced by the Serum Institute of India (SII). The vaccine was more than 90 percent effective in a late-stage US-based clinical trial, according to the company.
The government has also ordered 300 million doses of another vaccine from the Indian firm Biological E. There is no efficacy data available on the vaccine.
- The phase 3 data will now be reviewed by the DCGI. The Subject Expert Committee (SEC), however, has not discussed changing COVAXIN’s status of the vaccine from emergency use to full licensure, sources told The Print.
- The data will also be reviewed by the WHO on 23 June for in a “pre-submission meeting”, and pending approval Covaxin will be allowed for export to other countries.
With inputs from PTI
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