Phase-III trials of a vaccine made by India's Bharat Biotech showed it was 93.4 per cent effective against severe symptomatic Covid-19, the firm said, a finding that could boost people's acceptance of Covaxin.

The data demonstrated 65.2pc protection against the Delta variant, first identified in India, that led to a surge in infections in April and May, and the world's highest daily death tolls.

India's homegrown vaccine also showed effectiveness of 77.8pc against symptomatic Covid-19 in the trial, according to a Reuters report.