Another 200 million doses of any coronavirus vaccine are needed to get 10 per cent of the continent's population vaccinated by September, the WHO said.
WHO data shows 28 million doses from various manufacturers have reached Africa, which corresponds to fewer than two doses per 100 people, reported dpa.
Meanwhile, 1.5 billion coronavirus vaccine doses have been administered globally.
"Africa needs vaccines now. Any pause in our vaccination campaigns will lead to lost lives and lost hope," Matshidiso Moeti, WHO's regional director for Africa said.
It is too early to say whether Africa is on the cusp of a third wave, she said.
"However, we know that cases are rising, and the clock is ticking so we urgently appeal to countries that have vaccinated their high-risk groups to speed up the dose-sharing to fully protect the most vulnerable people."
The European Union and its member states have agreed to give more than 100 million doses to low-income countries by the end of 2021, and the United States has also agreed to make 80 million doses available for low-income countries, according to the WHO.