The World Health Organization (WHO) and the Africa Centres for Disease Control (Africa CDC) have urged African countries not to destroy Covid-19 vaccines that have expired.
The call comes after Malawi and South Sudan said they would discard more than 70,000 doses of the AstraZeneca jab that were out of date.
"Our advice would be that countries should ensure that they store the vaccines safely as we continue to study and try to get definitive advise on whether the vaccines can be used for longer," the WHO's Africa regional director Matshidiso Moeti said.
The Africa CDC says it has spoken to the manufacturer, Serum Institute of India (SII), and has been reassured that the vaccines are still safe.
"The vaccine landscape is extremely challenging and the advise we got from SII is that the vaccines can still be used even after nine months," John Nkegasong, the head of Africa CDC said.
Many vaccines can be used up to 36 months after manufacture, but because Covid-19 jabs are so new, there is not enough data to prove their effectiveness over longer periods.
Whatever the guidance, the final decision rests with national drug regulators.
However, the issue will further increase the challenges around persuading people on the continent to get vaccinated.
The rollout of Covid-19 vaccines in Africa has been slow, partly because of supply issues and scepticism about the jab.
Out of 55 African countries, 41 have benefitted from the delivery of vaccines via the global-sharing scheme Covax. Seven are yet to receive their first batch.