Covaxin from Bharat Biotech has an effectiveness of 81%. Here’s how it compares to Covishield from the Serum Institute

Bharat Biotech in a statement said the Covaxin vaccine was 81% effective in preventing Covid-19 after a third round of clinical trials. Covaxin demonstrated an interim 81% efficacy in preventing Covid-19 in people without previous infection after the second dose, the statement said.

Here’s what that data means and how it compares to India’s second vaccine option:

What is the meaning of efficiency?

Efficacy is calculated as a percentage and refers to the measure of the degree of protection of the vaccine against the virus, relative to the situation in which they were not vaccinated. The effectiveness is calculated on parameters such as the ability of the vaccine to prevent the onset of mild to severe symptoms even if you have been infected, to prevent you from becoming completely infected with the disease.

In the case of Covid-19 vaccines, pharmaceutical companies have mainly focused on reducing the number of symptomatic cases.

How does the effectiveness of Covaxin compare to Covishield?

In the case of Covaxin, data from 25,800 participants who received a vaccine 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 against 7 cases observed in the Covaxin group, resulting in a point estimate of the effectiveness of the vaccine at 80.6%.

Covishield, on the other hand, has an average 70.4% effectiveness in preventing Covid-19, according to interim analysis of its advanced stage clinical trials 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% effective.

What is the Covaxin platform?

Covaxin is based on a whole inactivated SARS-CoV-2 virion, an ancient platform that is also used to make polio vaccines. The disease-producing capacity of a virus is inactivated by this method.

How effective is Covaxin against the South African and British variant of the virus?

Covaxin has not yet been tested on this strain. However, in theory, inactivated vaccines, such as Covaxin, offer broader protection against mutant variants.

What are its procurement requirements?

Covaxin is stable between 2 and 8 degrees Celsius (refrigerator temperature) and ships in a ready-to-use liquid formulation that allows distribution using the existing vaccine supply chain.

What is the approval parameter of Covaxin?

On January 3, the Drugs Controller General of India (DCGI) approved Covaxin for “emergency use” in “clinical trial mode”.