When COVID burst onto the scene in late 2019, it came as a shock to most of the world's population and we've all been dealing with it ever since.

But to many researchers, it was less of a surprise and more of an inevitability - and now they're urging governments to act now to stop the next one.

It comes down to the old medical saying: prevention is better than cure.

So what can be done to help prevent the next pandemic and how much will it cost?