Africa has surpassed two million confirmed coronavirus cases as health officials warn of infections starting to creep up again into a second surge.

The Africa Centres for Disease Control and Prevention (CDC) said on Thursday that the 54-country continent has seen more than 48,000 deaths from Covid-19.

The continent of 1.3 billion people is being warned against "prevention fatigue" as countries loosen pandemic restrictions to ease their economies' suffering and more people travel.

Africa's CDC director John Nkengasong said: "We cannot relent. If we relent, then all the sacrifices we put into efforts over the past 10 months will be wiped away."

He expressed concern that "many countries are not enforcing public health measures, including masking, which is extremely important".

While the world takes hope from recent news about promising Covid-19 vaccines, African health officials also worry that the continent will suffer as richer countries buy up supplies.

Mr Nkengasong warned that the Pfizer vaccine requires storage at minus 70C, and such a requirement "already creates an imbalance in the fair distribution or access to those vaccines" as richer countries will be better equipped to move quickly.

A storage network at minus 70C was put in place for West Africa's devastating Ebola outbreak a few years ago, but that was localised, Mr Nkengasong said. "If we were to deploy across the whole continent, it would be extremely challenging to scale it," he said. "Let's be hopeful in coming weeks other vaccines will show more ease of distribution in resource-limited settings like Africa."

The Moderna vaccine requires storage at minus 20C, which Mr Nkengasong called promising. But the price of any Covid-19 vaccine is another factor in their fair distribution, he said.

But he offered an optimistic early look at attitudes across Africa towards any Covid-19 vaccine. Early data from a vaccine perception survey in 11 countries show 81% of respondents would accept a vaccine, he said.

In a separate briefing, World Health Organisation Africa chief Matshidiso Moeti acknowledged "very hot competition at the global level to reserve doses" but expressed her hope that "as time goes on, other countries are willing to, if you like, concede that you don't need to try to cover all the population at once".

Salim Abdool Karim, chairman of South Africa's Covid-19 advisory committee, said there was no sign that the vaccines now showing promise will not be just as effective in Africa as in their clinical trials elsewhere in the world.

Several African countries have confirmed virus cases in the six figures. South Africa leads with more than 750,000, while Morocco has more than 300,000, Egypt more than 110,000 and Ethiopia more than 100,000.

Kenya is the latest concern as it sees a fresh surge in cases.

At least four doctors died on Saturday alone, leading a powerful health union in the country to threaten a nationwide strike starting next month.

Africa has conducted nearly 20 million coronavirus tests since the pandemic began but shortages mean the true number of infections is unknown.