iI's actually a very colonial attitude to think the UK can solve the problems of the world
Good job the WHO didn't say that!
It was a general exhortation to all the rich countries who have secured supplies not to buy up so much that poorer nations cannot vaccinate.
It it The Guardian that has made it more click-baity by personalising it to UK (which of course counts in that category, but was not singled out)
We have already funded COVAX at a level only matched by Australia (if every country funded at the same proportion of economy size, the programme would be fully funded) and we have backed the development of the explicit not-for-profit AZ jab.
We have ordered way more vaccine than we need (because we ordered early and speculatively - it could have been a spectacular waste of money) and it is right that we relinquish our excess