Bharat Biotech’s COVID-19 vaccine: Phase 1 trials find no serious adverse events

New Delhi, Dec 17: The first homegrown Indian vaccine against COVID-19 has shown robust immune responses with barely any serious side-effects, according to the first scientific study of human trials of the vaccine.

The vaccine that is developed jointly by Bharat Biotech, Hyderabad and the Indian Council of Medical Research, popularly known as Covaxin was administered to 300 people. The results from these inoculations were compared to the results from 75 other subjects, who did not receive the vaccine.

The immune responses gave hints of long time efficacy and the the vaccine was administered in three doses. The research was carried out by Bharat Biotech, ICMR and the All Indian Institute of Medical Sciences, Delhi, along with doctors from other hospitals where the trials were conducted.

Based on these promising results, the Drug Controller General of India has permitted phase-3 of the clinical trials.

"The most common adverse event was pain at the injection site, which resolved spontaneously. The overall incidence rate of local and systemic adverse events was 10%-20% in all vaccine treated arms, which is noticeably lower than the rates for other SARS-CoV-2 vaccine platform candidates," the researchers said.

There was one serious adverse event when a participant who was screened on July 25 reported headaches and fever, five days after the vaccination. On August 8, he tested positive for COVID-19 and was admitted to hospital.

However he was found to be COVID-19 negative a week later. "The event was not causally associated with the vaccine. No other symptomatic SARS-CoV-2 infections were reported in the first 75 days," the researchers said.