About 40% of vaccines that have arrived so far on the continent have not been used, according to data from the Tony Blair Institute for Global Change, a policy think-tank.
When a group arrived at the Sekenani health clinic in rural Kenya for their Covid-19 vaccines recently, staff told them there were no doses left and that they should come back soon.
Shortages of funds, medical staff and equipment, and vaccine hesitancy were already hobbling inoculation campaigns in some parts of Africa. Experts warn that the anticipated surge, comprising millions of jabs in the coming weeks, could further expose those weaknesses.