Bharat Biotech says Covaxin generated robust immune response in monkeys

Bharat Biotech announced that its potential COVID-19 vaccine -- Covaxin -- was found to generate robust immune responses in rhesus macaques or monkeys, preventing infection and disease even upon high amounts of exposure to live SARS-CoV-2 virus.

The Hyderabad-based firm said data from the study on primates substantiate the immunogenicity of the vaccine candidate.

Covaxin developed by Indian Council of Medical Research (ICMR) and Bharat Biotech, is being tested at 12 institutes across India. Currently, the vaccine that contains inactivated SARS-CoV-2 virus is undergoing Phase II clinical trials.

Twenty macaques were divided into four groups of five animals each, it said.

One group was administered with placebo, while three groups were immunised with three different vaccine candidates at zero and 14 days.

All the macaques were challenged with SARS-CoV-2 14 days after the second dose. The results demonstrated that monkeys that received Covaxin have shown protective efficacy, increase in SARS-CoV-2 specific IgG and neutralising anti-bodies, reducing replication of the virus in the nasal cavity, throat, and lung tissues of the monkeys.

The company stated that there was no evidence of pneumonia was observed by histopathological examination in vaccinated groups, unlike the placebo group, which showed features of interstitial pneumonia and localisation of viral antigen in the alveolar epithelium and macrophages by immunohistochemistry.

The study results were published in preprint server, which means it isn't peer reviewed.

“Bharat Biotech proudly announces the animal study results of COVAXIN - These results demonstrate the protective efficacy in a live viral challenge model,” Bharat Biotech tweeted on September 11.