The African Union (AU) has dropped plans to secure coronavirus vaccines from the Serum Institute of India because of supply concerns and is instead exploring options with the US drugmaker, Johnson & Johnson.

The head of Africa's Centres for Disease Control, John Nkengasong, said reliable supplies of vaccines were vital - and that Indian restrictions on exports had complicated things for Africa.

He added that the AU's decision had nothing to do with the possible link to blood clots in rare cases involving the Oxford-AstraZeneca vaccine which will still be supplied to Africa through the UN's Covax scheme.

India's Serum Institute is licensed to make global supplies of AstraZeneca but Delhi has commandeered stocks to deal with surging infections.

Mr Nkengasong said the AU had already signed a deal for up to 400 million single dose jabs from Johnson & Johnson.