Covid: What is the Oxford vaccine and how does it work?

The coronavirus vaccine developed by the University of Oxford has been approved for use in the UK.

The UK has ordered 100 million doses from the manufacturer AstraZeneca - enough to vaccinate 50 million people.

The approval, by the medicines regulator, means the vaccine is both safe and effective.

Health correspondent Laura Foster explains how the vaccine works.

Video by Laura Foster, Mattea Bubalo and Aoife McKenna