Covaxin Phase 3 Trial Data Shows 77.8 Per Cent Efficacy Against Symptomatic COVID, Finds Study Published In Lancet

Hyderabad-based Bharat Biotech's Covaxin Covid-19 vaccine has demonstrated an efficacy of 77.8 per cent against symptomatic COVID-19 and is 93.4 per cent effective against severe symptomatic Covid-19 during the phase 3 trials, finds a study published in medical journal Lancet.

The Covaxin, also known as BBV152 vaccine, has been developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR).

"In the final per-protocol analysis, measured 14 days after the second of two doses of BBV152, we estimated a vaccine efficacy of 77.8% against symptomatic COVID-19 disease and, importantly, based on the limited data available, a higher efficacy against severe COVID-19 of 93.4%," said the study published on Thursday (11 November).

"This phase 3 study was done during a period that included the second wave of COVID-19 infections in India, with a peak of more than 400 000 new cases per day, when BBV152 was assessed against all ciruclating variants," it added.

Among 50 cases confirmed to be positive for the delta (B.1.617.2) variant, 13 were in the vaccine group and 37 were in the placebo group, resulting in a vaccine efficacy of 65.2 per cent, the study found.

Efficacy against the kappa (B.1.617.1) variant was 90·1 per cent, it added.

The study was conducted with participants from diverse geographical locations, enrolling 25,798 participants across 25 hospitals in India.

The most common solicited adverse event was pain at the injection site, followed by headache, fever, and fatigue. No severe or life-threatening solicited adverse events were reported, the study said.