Southern Africa is the most affected region, followed by the northern and eastern parts of the continent.
As many as seven in every 10 Africans accept the need for a vaccine to tackle the pandemic, higher than the average view in the US.
Only 17 percent of the continent's population will now be vaccinated by the end of this year, compared with the 40 percent target set by WHO.
AU says Africa wants to buy Covid vaccines, rather than keep waiting for donor-funded doses to arrive.
G7 pledged in June to provide a billion Covid vaccines for developing nations, up from 130 million promised in February.