NEW DELHI (BLOOMBERG) - Covaxin, a vaccine developed by India's government medical research agency and Bharat Biotech International, was found to have a 77.8 per cent efficacy rate against symptomatic Covid-19 in a long-awaited analysis published in The Lancet.
Covaxin, which uses traditional, inactivated virus technology, "induces a robust antibody response" two weeks after two doses are given, The Lancet said in a statement.
No severe vaccine-related deaths or adverse events were recorded during a randomised trial involving 24,419 participants aged 18 to 97 years between November 2020 and May 2021 in India, the medical journal said.
The interim study, which was funded by Bharat Biotech and the Indian Council of Medical Research and partly authored by officials at both bodies, is in line with the company's earlier efficacy and safety announcements and may help end the controversy surrounding the shot's early authorisation in January in India.
At the time, the shot had yet to clear final-stage trials, prompting widespread hesitancy in the early weeks of India's immunisation drive. Since then, more than 100 million doses of Covaxin have been deployed across India, with the World Health Organisation (WHO) adding the inoculation to its list of Covid-19 vaccines authorised for emergency use last week.
Yet, in the course of its analysis, the WHO independent technical body studying the vaccine repeatedly asked the company for further information, delaying its addition to the body's pre-qualified list and causing frustration for Prime Minister Narendra Modi's government, which had championed the locally developed shot.
Bharat Biotech chairman Krishna Ella had previously lashed out at those questioning Covaxin and this week told a conference that WHO approval took as long as it did because of criticism towards the vaccine, which hurt its image.
Further research will be needed to discover the vaccine's long-term safety and effectiveness, as well as protection against severe disease, hospitalisation and death, along with its ability to fend off the Delta and other variants of concern, according to The Lancet.
