Health authorities in Malawi have incinerated 19,610 expired doses of the AstraZeneca coronavirus vaccine, saying it will reassure the public that any vaccines administered on them are safe.

It is the first African country to publicly do this.

The World Health Organization initially urged countries not to destroy expired doses but has now changed its advice.

Uptake of the vaccination in Malawi has been low and health workers hope the move will increase public confidence.

Out of a population of about 18 million people, the country has recorded 34,232 confirmed coronavirus cases and 1,153 deaths.

Malawi received 102,000 doses of the AstraZeneca vaccine it acquired from the African Union on March 26 and used almost 80% of them.

But the expiry date on the labels was April 13 and officials say this wasn't enough time to use them all.

So in a 30-minute process, officials destroyed thousands of Covid-19 vaccines, leaving behind just broken pieces of the vials holding the liquid.

Malawi's principal health secretary told the BBC that it was unfortunate they had to destroy the vaccines but the benefits outweighed the risks.

"When news spread that we had out-of-date vaccines, we noticed that people were not coming to our clinics to get immunised," said Dr Charles Mwansambo.

"If we don't burn them, people will think that we are using expired vaccines in our facilities and if they don't come, Covid-19 will hit them hard."

The government says it has adequate stocks of vaccine and has urged everyone over 18 years old to get a jab.

In addition to the 102,000 from the African Union, it has received 300,000 doses under the Covax vaccine-sharing facility and 50,000 sourced direct from India.

However, future supplies could be threatened by India's decision to halt exports.

On the streets of the capital Lilongwe, some people are worried about the safety of the vaccine.

"I would like to get vaccinated but how sure am I if I go to the hospital I won't be given the expired vaccines?" shopkeeper Jack Chitete told the BBC.

"I have heard a lot of stories about people getting blood clots and some even dying after getting immunised. Are those people telling lies? If it is the truth, why are we being given the same vaccines?" asked another shopkeeper, Mphatso Chipenda.

The link between the AstraZeneca vaccine and rare blood clots is not yet proven, and health experts say the risk from Covid-19 is far higher. They advise people to get vaccinated if they can.

Malawi is not the only country in Africa to have expired vaccines. The WHO initially asked affected countries to hold onto the vaccines until it could establish whether they could still be used.

But it now says vaccines already sent out by the manufacturer with a set expiry date should be destroyed.

"While discarding vaccines is deeply regrettable in the context of any immunisation programme, WHO recommends that these expired doses should be removed from the distribution chain and safely disposed of," it said in a statement on May 17.

Other vaccines that are currently in use have a shelf life of up to 36 months. The challenge with Covid-19 vaccines is that they have been in use for less than a year and there is no substantive data around their effectiveness after long periods.