A special plane carrying a consignment of Ebola vaccine landed in Guinea on Monday night.
A dust storm in the Sahara on Sunday had forced the aircraft off course and diverted it to Senegal, delaying vaccine rollout by a day.
Vaccinations are to begin in Guinea’s capital, Conakry, on Tuesday.
Most of the 11,000 doses are to be taken to the south-eastern town of Nzérékoré.
Five people have recently died there from Ebola.
It’s West Africa’s first outbreak of the deadly haemorrhagic fever since 2016.