Why is it taking so long to develop a Covid-19 vaccine?

The race is on for the world’s scientists to develop a safe and effective Covid-19 vaccine. The Inquiry examines quickly how this can be done and what hurdles need to be overcome to roll out a vaccine in 12-18 months, rather than the many years it would normally take. Presented by Kavita Puri. (medical doctor with a vaccine. Credit: Getty images)