Vaccines are not yet Africa's antidote to the coronavirus pandemic, a regional health official said on Thursday, after the African Union (AU) secured 270-million doses for the continent where a second wave is infecting about 30 000 people a day.

Africa has not started vaccinations and there is concern that more prosperous regions will get an unfair head start in the global fight against Covid-19.

But there was heartening news on Wednesday when AU chair South Africa said doses would be supplied this year by Pfizer, AstraZeneca - through the Serum Institute of India - and Johnson & Johnson.

The 270-million shots, however, if administered two per person, would only cover around 10% of Africa's roughly 1.3-billion people.

"We should not see vaccines as a magic bullet for now, it will take time for vaccines to be rolled out in a way that we have herd immunity," said John Nkengasong, director of the AU's Africa Centres for Disease Control and Prevention (CDC).

Africa's second coronavirus wave is infecting twice as many people per day as the height of the first wave last year, and has not peaked, said Nkengasong.

Infections have passed 3.1-million with more than 74 600 deaths over the course of the pandemic.

Speaking in an online press briefing, Nkengasong urged countries to keep public health measures such as mask wearing and movement restrictions.

However, nations should also start placing orders and approve the vaccines as a bloc or blocs, to accelerate getting doses out. "There is a fierce urgency of now," he said.

The Africa CDC boss brushed aside concerns that lack of ultra-cold chain storage infrastructure would stop countries buying and using vaccines needing to be kept at extremely low temperatures - Pfizer's and Moderna's.

Countries would store and dole out such vaccines in cities, where demand is high and freezers can be maintained, he said.