British Foreign Secretary Dominic Raab has called on high-income countries to support global access to Covid-19 vaccines.

Speaking in Kenya's capital, Nairobi, at the start of his visit to East Africa, Mr Raab said the UK had provided £500m ($684m) to aid the distribution of vaccines across the world through an initiative dubbed Covax.

The African Union has secured 270 million vaccine doses from manufacturers for member states, but that is still not enough to meet demand for the more than one billion people on the continent.

Western countries have been accused of buying almost all doses of the leading vaccines, leaving poorer nations uncertain of when they will get the shots.

The World Health Organization said it could become a "catastrophic moral failure" that would cost lives and livelihoods.

Mr Raab on Wednesday toured the Kenyan research centre taking part in the Oxford vaccine research.

Even though doses are now being administered in the UK, none have been made available in Kenya.

Mr Raab said it was in the UK's national interest and its moral duty to get the vaccine there as soon as physically and logistically possible.

But it’s not just Kenya. Middle and lower income countries have struggled to find vaccines.

Wealthy countries have signed deals to buy as much as five times the quantities they need.