Now that rich nations are sharing more Covid-19 shots with Africa, health officials across the continent are scrambling to overcome vaccine hesitancy and logistical problems to get the doses into arms fast enough before they expire.

Penda Health, a Nairobi-based chain providing low-cost private healthcare, has found a way to speed things up: bring the shots closer to people's homes.

For many Kenyans, travelling to one of the big hospitals prioritised as vaccine centres meant lost earnings to take time off work and finding transport they could ill afford. So many didn't go.

But this week, dozens of people patiently queued up for a shot outside Penda's Tassia Medical Centre, a clinic now delivering the vaccine on their doorstep in one of Nairobi's poorer neighbourhoods.

"It's closer to my place. I have a son so it's more accessible. I just walk a minute and I'm here," said Nancy Mwebi, 26, adding that many of her friends had feared they would be charged for the doses once they reached a big hospital.

With just 7% of people fully vaccinated across Africa and supplies of vaccines improving, experts are urging African governments to copy the kind of approach taken by Penda to improve take up across the continent.

When Penda noticed many of its patients were unable to access vaccines after doses began arriving in Kenya in March, it approached the health ministry to set up a partnership.

But Penda, founded in 2012, still only offers shots in seven of its 21 clinics in Nairobi because of the expenses involved in rolling out the programme.

The shots may be free but Penda has to pay 240 000 Kenyan shillings ($2 100) for World Health Organization-approved refrigerators to store them and staffing costs to administer the vaccine and keep records amount to $1 000 per clinic per month.

"It's a small price to pay to get this many shots in arms, but on the other hand, it is very challenging for the narrow margins we have at our medical centres," said Penda's chief medical officer Dr. Robert Korom.

Last week, Penda administered about three in every 1 000 Covid vaccines given in Kenya, data from Penda and the ministry of health showed.

"The ministry of health is aware that vaccination needs to get to the last mile and especially in villages and grassroots," Andrew Mulwa, the ministry's acting director of medical services, told Reuters.

He said partners, including private sector players, were critical to achieve Kenya's target of vaccinating the entire adult population by the end of 2022.