The UN's children's agency, Unicef, is urging the world's richest countries to donate a fifth of their Covid vaccines to 18 African nations who are running out of supplies.

Vaccine manufacturers have been unable to keep up with demand, mainly because of the sharp increase in infections in India.

Doses from the main supplier, the Serum Institute, are being diverted for domestic Indian use.

But a few wealthy countries are also accused of hoarding vaccines leaving the world's poorest the last in line to be vaccinated.

The G7 group's health ministers are meeting in the English city of Oxford on Thursday to discuss better sharing of information about emerging infectious diseases, to prevent them from becoming future pandemics.