Abubakar Yusuf, an informal Nigerian trader, said he was scared to get a Covid-19 shot after hearing the country had stocks of expired vaccines. That changed, however, when health authorities destroyed more than a million expired doses last month.

Nigeria's vaccine rollout has slowly gained pace since then as public confidence increases and the government has assured citizens they will not receive expired doses.

Nigerians like Yusuf were rattled by reports of vaccines with looming expiry dates and worried about whether the shots they would get were safe and effective, complicating the government's efforts to get as many shots into arms as possible.

Nigeria, like other African countries, initially struggled to get doses as rich nations snapped up limited supplies. Deliveries later picked up, but some shots donated by individual countries or via the global vaccine-sharing scheme COVAX arrived with a very short shelf life, leading them to expire.

Nigeria has said it will no longer accept vaccines close to expiry.

The daily vaccine uptake doubled to 200,000 doses in December and January, Faisal Shuaib, head of the National Primary Health Care Development Agency said.

"We've been scared before, seriously," Yusuf told Reuters after getting an AstraZeneca dose at a market in Abuja. "But the way people have been taking it [the vaccine], they are well, they are doing their normal business... so we decided to take it."

In December, Nigeria destroyed more than a million doses of expired AstraZeneca (AZN.L) vaccines as it sought to assure a wary public that they had been taken out of circulation.

That seemed to have convinced Gabriel Allesiloye to get a shot.

"It's good for government to discard those ones... and they have done so... it is good for us to take it," said Allesiloye, who described himself as a Christian evangelist, after getting his Covid-19 shot at the Abuja market.

John Nkengasong, director of the Africa Centres for Disease Control and Prevention, Africa's top public health body, told a virtual media briefing on Thursday that news of expired vaccines had created "some kind of hesitation" among sceptical citizens.

He said last week that roughly 0.5% of the 572 million doses delivered to date had expired. Other African countries have also destroyed them like Nigeria.

Africa's public health bodies have now called for donated vaccines to come with a shelf life of three to six months.

Nkengasong noted more African countries were recording increases in the number of people being vaccinated as communication and community engagement improved, he said.

Around 2.6% of Nigeria's population have been fully vaccinated, while 14 million received a first dose.

Reuters