COVID-19 | AstraZeneca and Oxford University have more work to do to confirm whether their Covid-19 vaccine can be 90 percent effective, peer-reviewed data published in The Lancet showed on Tuesday, potentially slowing its eventual rollout in the fight against the pandemic.

Once seen as the frontrunner in the development of a vaccine against the coronavirus crisis, the British team were overtaken by US drugmaker Pfizer, whose shots - with a success rate of around 95 percent - were administered to UK pensioners on Tuesday in a world-first hailed as V-Day.

Detailed results from the AstraZeneca/Oxford trials have been...