British-Swedish drugmaker AstraZeneca revised down the efficacy figure for its two-dose Covid vaccine following a clinical trial held across the United States, Peru and Chile.

The company now says its vaccine is 76 per cent effective rather than 79pc effective at preventing any kind of symptomatic Covid, AFP reported.

An independent panel of experts appointed to supervise the trial said AstraZeneca failed to include updated data after the company announced the first figure.