Covaxin safe, immunogenic with no side effects, says Lancet

Medical peer-review journal Lancet has published the interim results for phase 2 trials of Bharat Biotech's COVID-19 vaccine, Covaxin, calling it 'safe, immunogenic with no serious side effects'.

The double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of Covaxin (BBV152) in healthy adults and adolescents (aged 12-65 years) was carried out at nine hospitals in India.

"In the phase 1 trial, BBV152 induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination. In the phase 2 trial, BBV152 showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial," it said.

The most common adverse event in the phase 2 trial was pain at the injection site, followed by headache, fatigue, and fever. No severe or life-threatening (i.e. grade 4 and 5) solicited adverse events were reported.

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"After either dose, the combined incidence of local and systemic adverse events in this study is lower than that of other SARS-CoV-2 vaccine platform candidates, and similar to that of other inactivated SARS-CoV-2 vaccine candidates," the study said.

This is the only study of an inactivated COVID-19 vaccine candidate to report a thorough evaluation of cell-mediated responses, Lancet said.

"The 6 microgram with Algel-IMDG formulation has been selected for the phase 3 efficacy trial. BBV152 (developed using a well established manufacturing platform) was safe, immunogenic (persisting for 3 months), and can be stored at 2-8 degree Celsius, which is compatible with the immunisation cold chain requirements of most countries," it added.

Last week, Bharat Biotech has announced the phase 3 clinical trial results for Covaxin. The company said Covaxin demonstrated efficacy of 81 per cent in the trials.

Also read: Covaxin exceeds efficacy of most traditional platform-based COVID-19 vaccines