Why are COVID-19 vaccines going to waste?

In the fight against Covid-19, every vaccine counts.
And yet, both Malawi and South Sudan say they may destroy as many as 70,000 doses of the Oxford-AstraZeneca jab. They say the vaccines may have passed their expiry date.
Last week, the World Health Organization pleaded with them not to go ahead with the plan.
“The Ministry of Health is still in communication to reach an amicable resolution,” says South Sudan’s UK Ambassador Agnes Oswaha. “There is no decision made yet to dispose of the vaccines.”
But some say this impasse may affect public confidence on the vaccine.
“In terms of perception, in terms of communication, I don’t think that it will be useful,” says Yap Boum, regional representative for Africa for Epicentre, the research arm of Doctors Without Borders.
Malawi has said it will go ahead and destroy more than 16,000 doses of expired Oxford-AstraZeneca vaccines despite the World Health Organization (WHO) advising against it.
So, why exactly are so many vaccines at risk of going to waste? What exactly went wrong?