Dr Thomas House is a mathematical epidemiologist and one of the scientists advising the government during the current coronavirus crisis.
He works at the University of Manchester and is a member of a national committee which specialises in mathematical modelling.
We asked Dr House about all we know - and what we don't - about the pandemic. What is COVID-19 and how do you see it? It's a viral pathogen which colonises your respiratory tract and lungs.
It's spread from person to person. It's one of the big challenges that our generation of humans has got to deal with. What do you think started the pandemic? We don't know.