Quite a few pp have said that it's in our interests to ensure the vaccination is rolled out at the same rate worldwide, in order to stop the virus mutating into new variants.
That argument holds no water. Mutations happen when the virus passes from one person to the other. Whether the patient dies has no bearing on it at all. Vaccinating vulnerable people first doesn't reduce the risk of the virus mutating.
The most effective way to limit new variants is to vaccinate the people most likely to transmit the virus, not those most likely to die from it. The incidence of the virus in that country is the biggest factor. It's no coincidence that the worrying new variants have come out of the UK, South Africa and Brasil - where there is a high incidence of the virus and it's spreading fast.
To limit the risk of virus mutation, a 22 year old shopkeeper in San Paolo, Jo'burg or London should be prioritised over an 82 year old in Ethiopia or Australia.
Of course, there's a separate humanitarian drive to limit deaths - but let's not conflate these goals.
And within a country, there are other factors as well as the risk of new variants: a duty of care to the whole population; the need for perceived fairness, so that people will accept political choices and continue to pay tax; keeping shared resources like the NHS afloat, maintaining the economy. In choosing vaccine priority groups, each government weighs all these up.
I don't feel we're anywhere near the point where it would be responsible for the UK to slow our vaccine roll out and give our vaccine supplies away. Not when the virus incidence is so high here. And that's both on a humanitarian basis (UK deaths per population still one of the highest in the world, and our NHS is barely coping) as well as being the best way we can reduce the risk of virus mutation worldwide (since we are currently one of the highest risk places for that to happen)