Only 15 of Africa's 54 nations have fully vaccinated 10% of their populations against COVID-19 and many frontline health workers remain at risk, the World Health Organisation (WHO) and International Council of Nurses (ICN) said on Thursday.

They called for speeding up distribution of doses to those at risk on the continent amid what the WHO called "opaque delivery plans" and "bottlenecks" in the rollout of vaccines in Africa.

The WHO had called for vaccinating at least 10% of health workers in every country by Sept. 30 - a target met by nearly 90% of high-income countries, the United Nations health agency said.

Half of the 52 African countries that have received COVID-19 vaccines have fully vaccinated just 2% or less of their populations, WHO's regional office in Brazzaville said in a statement.

Howard Catton, chief executive officer of the Geneva-based ICN, told Reuters that it analysed data from nine African countries.

It showed that approximately a third of health workers were still waiting for their first dose of vaccine and only about 10 percent had been fully vaccinated.

"Despite the promises, we are not seeing the delivery And this is a health and a human rights crisis," he said. "Today nurses and health workers are still going to work knowing that they are at higher risk, but not having the protection of vaccine."

In the meantime, some rich countries are already administering booster shots and vaccines to youth, he said.

"You know, we have just seen a billionaire send a healthcare worker into space, yet, here on earth, we have millions of healthcare workers still waiting to be vaccinated. They shouldn’t have to wish on a star for a vaccine, they should be prioritized," Catton said.

Richard Mihigo, coordinator for the WHO's Immunization and Vaccines Development Programme Africa, told a briefing: "What the data is showing us - in the 39 countries where we were able to collect that information, 8% of all the doses administered in those 39 countries were administered to healthcare workers."

Some healthcare workers in remote rural areas have not been reached, he said.