Homegrown vaccine maker Bharat Biotech has said the animal trials of its COVID-19 vaccine candidate, COVAXIN, were successful and it generated a robust immune response in animals. Hyderabad-based Bharat Biotech is developing COVAXIN in collaboration with the Indian Council of Medical Research (ICMR)-National Institute of Virology (NIV), Pune.
The vaccine maker, in its animal study, said a two-dose vaccination regimen of inactivated SARS-CoV-2 vaccine candidates was administered in 20 rhesus macaques (a species of monkey), divided into four groups equally.
One group was administered with placebo, while three groups were immunised with three different vaccine candidates at 0 and 14 days. Thereafter, all the macaques were exposed to viral challenge 14 days after the 2nd dose.
"The results showed protective efficacy, increasing SARS-CoV-2 specific IgG and neutralising antibodies, reducing replication of the virus in the nasal cavity, throat, and lung tissues of monkey," a statement from Bharat Biotech said. It added that no evidence of pneumonia was observed during histopathological (microscopic) examination in vaccinated groups, unlike the placebo group.
"Adverse events were not seen in animals immunised with a two-dose vaccination regimen," it added. The company said its vaccine candidate was found to generate "robust immune responses", thus preventing infection and disease in the primates upon high amounts of exposure to live SARS-CoV-2 virus.
Bharat Biotech is among the three vaccine makers in India after Zydus Cadila and Serum Institute of India, which have finished phase 1 of human trials, which have moved to phase 2/3.
Adar Poonawalla-led SII, which has partnered with AstraZeneca and University of Oxford to develop a COVID-19 vaccine, had to stop phase 2/3 trials after AstraZeneca paused its trials as a UK participant developed an unexplained illness.
The Drug Controller General of India, Ministry of Health & Family Welfare had granted Bharat Biotech permission to initiate Phase I & II human clinical trials in June after the company submitted preclinical studies, which demonstrated safety and immune response.
As per the company, Bharat Biotech has so far innovated more than 140 global patents, a wide product portfolio of more than 16 vaccines, 4 bio-therapeutics, registrations in more than 116 countries and WHO pre-qualification.