Bharat Biotech concludes Phase 3 trial for Covaxin, claims 65.2% efficacy against Delta variant

India, July 3: The Hyderabad-based Bharat biotech said in the wee hours of Saturday that it has concluded the final analysis for Covaxin efficacy as part of the phase 3 clinical trial.

The company has claimed that its vaccine demonstrates overall efficacy of 77.8% against symptomatic infection while sharing the final phase-3 pre-print data on medRxiv.

Covaxin has shown 93.4% efficacy against severe infections and provides 65.2% protection against the B.1.617.2 (Delta) a variant, which is currently dominant in India, it further added.

Bharat Biotech is called to be “India’s largest efficacy trial“, over 25,798 participants between 18 and 98 years of age were recruited from 16 November year to 7 January 2021.

The final analysis deployed a double-blind, randomized, multi-centre clinical trial, using a sponsor-supplied randomization scheme. A total of 24,419 received two doses of the vaccine or placebo four weeks apart.

The company said that 130 cases of symptomatic Covid-19 infections were reported in 16,973 (0.77%) participants at least two weeks after the second dose — 24 occurred in the vaccine group and 106 in placebo recipients giving an overall vaccine efficacy of 77.8%.

In addition to this, 16 cases, one vaccine and 15 placebo recipients met the severe symptomatic Covid-19 case definition giving a vaccine efficacy of 93.4%.

Covaxin’s efficacy against asymptomatic Covid-19 was 63.6%.

Also Read: Covaxin effective against Delta variant of coronavirus, says U.S.’ health research institute


BBV152 was well tolerated with no clinically or statistically significant differences in the distributions of solicited, unsolicited, or serious adverse events between vaccine and placebo groups. No cases of anaphylaxis or vaccine-related deaths were reported,” the analysis statement read.

The vaccine was immunogenic and highly efficacious against symptomatic and asymptomatic Covid-19 variant associated disease, particularly against severe disease in adults,” it added.


Phase 3 trial data for Covaxin

An expert panel of the country’s central drugs authority reviewed and accepted the phase-3 trial data of Bharat Biotech’s Covaxin last month.

Covaxin is one of the three vaccines approved by the DGCI for emergency use and is being deployed in the Covid-19 vaccination programme. The absence of its phase-3 data has been a topic of contention for a long.

The company has developed the vaccine in association with the Indian Council of Medical Research (ICMR).