Celebrated as our national jab, the Oxford-AstraZeneca vaccine has been praised as a 'remarkable example of British innovation and scientific excellence' and recognised for its success at home.

Celebrated as our national jab, the Oxford-AstraZeneca vaccine has been praised as a 'remarkable example of British innovation and scientific excellence' and recognised for its success at home. Around half of all adults in the UK received two doses of it.

But when Oxford scientists developed the jab, they had far greater ambitions: a 'vaccine for the world', designed specifically to be distributed to lower income countries and sold at cost for the duration of the pandemic. For both humanitarian and scientific reasons, they argued sharing vaccines fairly globally was the best way to bring coronavirus under control.

A year later, more than 2.5 billion doses have been distributed worldwide. But with only one in 20 people in low income countries double jabbed and the Omicron variant spreading globally, how far did the vaccine meet its original purpose?

Beset by challenges including supply disputes in Europe and, concerns over rare blood clots, the vaccine has never been approved in the US and is now barely used in the UK. So how much were these problems self-inflicted, or did nationalist politics get in the way?

The BBC's medical editor, Fergus Walsh, who has been reporting on the vaccine since its early development, examines the challenges this jab faced in Europe and beyond, and asks if it fulfilled the original hopes of the scientists in Oxford.