The Africa director for the World Health Organization on Thursday warned that countries that "hoard" COVID-19 vaccines make a "mockery of vaccine equity" and said that rollouts of booster shots by some wealthier nations "threaten the promise of a brighter tomorrow for Africa."

Matshidiso Moeti and other African health officials, including the Africa Centers for Disease Control and Prevention, had warned against booster shots in recent weeks as less than 2% of the population on the continent of 1.3 billion people is fully vaccinated against COVID-19.

Moeti noted that the latest resurgence in cases across Africa is leveling off and more vaccine doses are finally arriving on the continent, but "Africa is encountering headwinds" as rich countries like the United States decide to roll out booster shots.

The situation in Africa remains "very fragile" as the more infectious delta variant is now dominant in most of the continent’s 54 countries, she said. More than 7.3 million cases, including more than 186,000 deaths, have been confirmed across the continent and health systems are straining to provide medical oxygen and other care.

U.S. health officials on Wednesday announced plans to dispense COVID-19 booster shots to all Americans amid the surging delta variant and signs that vaccines’ effectiveness is slipping.

Moeti told reporters she couldn’t say with any accuracy whether the doses the U.S. plans to use for booster shots will come from stocks that had been planned for Africa, but "hopefully not."

She noted the "already highly inequitable situation" globally in vaccine supply and urged that the emphasis instead be placed on making progress in vaccinating people in Africa, whose countries lag far behind much of the world in access and coverage.

Moeti pointed out that rich countries have on average administered more than 103 vaccine doses per 100 people, while in Africa it’s just six.

Earlier this month, the World Health Organization called for a moratorium on COVID-19 vaccine booster shots until at least the end of September to address the drastic inequity in dose distribution between rich and poor nations.