The World Health Organization (WHO) and its partners say around 18 million doses of the world's first malaria vaccine will be delivered to 12 African nations by 2025.

Among them are Malawi, Ghana and Kenya, where the Mosquirix vaccine has already been used in pilot schemes.

With demand outstripping supply, priority will go to countries with the greatest need, and where maximum impact will be achieved.

Mozambique and Sudan have been excluded because of their high vaccine drop-out rates.

The WHO says the vaccine - developed by the British firm GSK - could save one life for every 200 children vaccinated.

Malaria kills around half a million African children under five each year.