Healthcare workers in the Ivory Coast city of Abidjan will get Covid vaccinations on Monday.
It is the first national rollout of the UN-backed Covax programme – the global vaccine-sharing initiative to help poorer countries control the pandemic.
They will be the initial recipients of half a million doses of the AstraZeneca Oxford vaccine.
Ghana and Nigeria are due to start their mass inoculations on Tuesday.
COVAX is the biggest vaccine procurement plan in human history, designed to distribute two billion doses by the end of the year.
But this only covers 20% of the populations of developing countries. Most rich countries have ordered sufficient stocks to treat their entire populations.