The thing about this coronavirus that scares me is the speed at which it seems to be spreading.

Latest figure show 50 deaths in China. Nearly 2,000 confirmed cases there, and the same number again of suspected cases. On top of that, this bug is like a flu: you can be contagious before you show any symptoms.

One senior doctor in the States is calling that the game changer.

15 big cities in China are essentially in lockdown, but with this virus being transmittable as quickly and easily as it is, you have to ask if that's going to achieve much at all.

And should we trust the numbers from China? There are cases in the US, and cases in Australia. The likelihood is this disease is probably already here too.

So, from today, we're going to be screening people at the airports. Five flights come in today: people will be approached and offered advice on what to do if they get ill.

Some people say we shouldn't be letting those people in at all. But the fact is people on any flight from anywhere on the planet could be bringing it in.

That's the reality of the interconnected world we now live in. And now we know this thing can pass from person to person before anyone shows symptoms, how do we stop it?

Answer is: we can't.

It's almost certain some people on those inbound flights today will have it. And they'll have coughed and sneezed it all over the aircraft cabin. If it's not here already, coronavirus will reach New Zealand sooner or later.

So, apart from shutting ourselves up in hermetically sealed rooms and waiting it out...what do we do? We do the best we can, we prepare.

We weed out people who've got it as quickly as we can. Most importantly, we spare no expense protecting our health workers and contributing to the global effort to create a vaccine.

This is not a time to be penny pinching.