With cases now doubling in Africa every three weeks, the Delta variant of COVID-19 has spread to 16 countries and it is present in three of the five nations reporting the highest caseloads, according to the World Health Organization (WHO). The variant is the most contagious yet – up to 60% more transmissible than other variants.

Along with Alpha and Beta, Delta is fuelling an aggressive third wave across Africa, with case numbers climbing faster than all earlier peaks, the UN agency said.

WHO experts warned on Thursday that the numbers have increased for six consecutive weeks, up by 25% last week, reaching 202,000 positive cases. Deaths also rose by 15% across 38 African countries, to nearly 3,000.

The Delta variant, initially identified in India, is now dominant in South Africa, which accounted for more than half of Africa´s cases last week. Moreover, the variant was detected in 97% of the samples sequenced in Uganda and 79% of those sequenced in the Democratic Republic of the Congo.

The variant also seems to be fuelling illness among young adults. According to WHO experts. In Uganda for example, 66% of severe illness in people younger than 45, is attributed to Delta.

“The speed and scale of Africa’s third wave is like nothing we’ve seen before. The rampant spread of more contagious variants pushes the threat to Africa up to a whole new level. More transmission means more serious illness and more deaths, so everyone must act now and boost prevention measures to stop an emergency becoming a tragedy,” said Dr. Matshidiso Moeti, WHO´s regional director for Africa.

The Alpha and Beta variants have been also reported in 32 and 27 countries respectively. Alpha has been detected in most countries in north, west and central Africa, while Beta is more widespread in the south. Both are considerably more transmissible than the original virus.

With rising case numbers and hospitalizations across the continent, WHO estimates that oxygen demand in Africa is now 50% greater than for the first wave peak, one year ago. Eight vaccines have been approved for the WHO emergency use listing, however, shipments to Africa have, in effect, dried up.

“While supply challenges grind on, dose sharing can help plug the gap. We are grateful for the pledges made by our international partners, but we need urgent action on allocations. Africa must not be left languishing in the throes of its worst wave yet,” added Dr. Moeti. Only 15 million people – a mere 1.2% of the African population – are fully vaccinated.