COVID-19 Vaccine Trials: Covaxin Found Effective In Non-Human Primates

New Delhi: Covaxin, the indigenously developed COVID-19 vaccine, has demonstrated protective efficacy and immunogenicity in non-human primates in Phase I clinical trials in India.

Covaxin, which is developed by Bharat Biotech and ICMR, is being tested at 12 institutes across India. The results of the first phase of testing are encouraging, Bharat Biotech has reported.

Researchers said a two-dose vaccination regimen of inactivated coronavirus vaccine candidates was administered in 20 rhesus macaques (divided into four groups equally), India Today reported.

One group was administered with placebo, while three groups were immunized with 3 different vaccine candidates at 0 and 14 days. All the macaques were exposed to viral challenge 14 days after the 2nd dose.

The results showed protective efficacy, increasing coronavirus specific IgG and neutralizing antibodies, which reduced replication of the virus in the nasal cavity, throat and lung tissues of monkey.

No evidence of pneumonia was observed by histopathological examination in vaccinated groups, unlike the placebo group.

Adverse events were not seen in animals immunized with a two-dose vaccination regimen.

“To summarize, the vaccine candidate was found to generate robust immune responses. Thus, preventing infection and disease in the primates upon high amounts of exposure to live coronavirus,” said a researcher.