Covid-19: Challenges of delivering a vaccine globally

Virologist Prof Barry Schoub, who is the chairman of South Africa’s ministerial advisory committee on coronavirus vaccine development, has warned there are still a number of challenges ahead in distributing a Covid-19 vaccine around the world.

The first effective coronavirus vaccine needs to be stored at ultra-cold temperatures and this would be a problem for countries like South Africa, Prof Schoub told BBC World News.

"As it stands at the moment if there is a storage requirement of -70C that will be a major, major challenge but there is some research which is going on to try and lower that requirement," he said.

A number of trials are currently underway in South Africa.