Bharat Biotech's Covaxin shows 81% efficacy in phase-3 trials
04 March 2021
Bharat Biotech’s indigenous vaccine for Covid-19, which has been criticised for its early approval for emergency use, has been found to be more effective than its proven peer Covishield, being manufactured by Serum Institute of India under licence fron AstraZenica/Oxford University.
Bharat Biotech in a statement said that Covaxin was found to be 81 per cent effective in preventing Covid-19 after a third round of clinical trials. Covaxin demonstrated 81 per cent interim efficacy in preventing Covid-19 in those without prior infection after the second dose, according to the statement.
A vaccine’s efficacy is calculated in percentage terms and denotes the measure of how much protection the vaccine provides against the virus, compared with the situation in which they were not vaccinated. Efficacy is calculated on parameters such as the ability of the shot to prevent mild to severe symptoms from showing even if you have been infected, to preventing you from getting infected with the disease altogether.
Data collected from 25,800 participants received Covaccine or placebo in a 1:1 ratio showed that the vaccine candidate was well tolerated
The first interim analysis is based on 43 cases, of which 36 cases of Covid-19 were observed in the placebo group versus 7 cases observed in the Covaxin group, resulting in a point estimate of vaccine efficacy of 80.6 per cent.
Covishield, on the other hand, has an efficacy of 70.4 per cent on an average in preventing Covid-19, as per the interim analysis of its late-stage clinical trials conducted in the UK and Brazil.
In Brazil, two full doses of the vaccine were given one month apart, involving 8,895 participants, and the vaccine appeared to be 62 per cent effective.
Covaxin is based on an inactivated whole SARS-CoV-2 virus, a method that is also used to make polio vaccines.
Covaxin, India's indigenous Covid-19 vaccine, developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV), is an inactivated vaccine.
The vaccine is developed using Whole-Virion Inactivated Vero Cell derived platform technology. Inactivated vaccines do not replicate and are therefore unlikely to revert and cause pathological effects. They contain dead virus, incapable of infecting people but still able to instruct the immune system to mount a defensive reaction against an infection.
Covaxin is included along with immune-potentiators, also known as vaccine adjuvants, which are added to the vaccine to increase and boost its immunogenicity.
It is a 2-dose vaccination regimen given 28 days apart.
It is a vaccine with no sub-zero storage, no reconstitution requirement, and ready to use liquid presentation in multi-dose vials, stable at 2-8oC.