New COVID-19 Vaccine Shows Good Efficacy and Toxicity Profile

Dawn O'Shea

November 18, 2021

A randomised, double-blind, placebo-controlled, multicentre, phase 3 clinical trial has found that a new SARS-CoV-2 vaccine is “highly efficacious against laboratory-confirmed symptomatic COVID-19 disease”.

Covaxin (code-named BBV152) is a whole virion inactivated SARS-CoV-2 vaccine, formulated with a toll-like receptor 7/8 agonist molecule adsorbed with alum (Algel-IMDG). It has been developed by Bharat Biotech International and trialled in 25 Indian hospitals and medical clinics to determine its efficacy in preventing a first occurrence of laboratory-confirmed symptomatic COVID-19 (any severity), occurring at least 14 days after the second dose.

The trial recruited 25,798 participants. A total of 24,419 received two doses of BBV152 (n=12,221) or placebo (n=12,198).

Interim results published in  The Lancet  show that the vaccine had an overall estimated efficacy of 77.8% (95% CI 65.2 to 86.4). A higher efficacy was seen against severe disease (93.4%; 95% CI 57.1 to 99.8).

In the safety population (n=25,753), 5959 adverse events occurred in 3194 participants. The same proportion of participants reported adverse events in the vaccine group (12.4%) and placebo group (12.4%), with no clinically significant differences in the distributions of solicited, unsolicited, or serious adverse events between the groups, and no cases of anaphylaxis or vaccine-related deaths.

Ella R, Reddy S, Blackwelder W, Potdar V, Yadav P, Sarangi V, et al; COVAXIN Study Group. Efficacy, safety, and lot-to-lot immunogenicity of an inactivated SARS-CoV-2 vaccine (BBV152): interim results of a randomised, double-blind, controlled, phase 3 trial. Lancet. 2021 Nov 11:S0140-6736(21)02000-6. doi: 10.1016/S01406736(21)02000-6. Epub ahead of print. PMID: 34774196.


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