Most African countries are on course to miss the goal of vaccinating the most vulnerable 10% of their population against COVID-19 by end of September, the World Health Organization (WHO) said Thursday, as it blamed wealthy nations for hoarding shots.

Forty-two of Africa's 54 nations, nearly 80%, are set to miss the target unless the current pace of vaccine deliveries and vaccinations increases, the WHO's Africa office warned.

"Vaccine hoarding has held Africa back and we urgently need more vaccines," said Dr. Matshidiso Moeti, WHO regional director for Africa.

"As more doses arrive, African countries must zero in and drive forward precise plans to rapidly vaccinate the millions of people that still face a grave threat from COVID-19," she added.

According to the WHO, the supply of COVID-19 vaccines to Africa has been improving with almost 21 million doses arriving in August, via the international COVAX distribution system.

This equaled the tally for the previous four months combined.

"Africa is set to miss the urgent global goal of vaccinating the most vulnerable 10% of every country's population against COVID-19 by the end of September," the WHO warned.

But with more vaccines expected from COVAX and the African Union by the end of September, the target remains possible, it added.

On top of that, 26 countries have used less than half of the COVID-19 vaccine doses they already have.

Experts worry that reluctance to take the vaccine, stemming from public skepticism over foreign-procured jabs and fear of side effects, may prolong the pandemic in Africa, a continent of nearly 1.3 billion people

The WHO said that the coronavirus case numbers have been declining slightly in Africa "but remain stubbornly high."

Nine African nations, including South Africa, Morocco and Tunisia, have already reached the WHO's 10% vaccination goal.