How will we know if we're reopening too fast?

As more and more of the country is vaccinated, state and territory governments are starting to outline which restrictions we will lose when we reach very high levels of coverage.

Over the weekend, Victoria revealed that when it reaches 90 per cent double dose in a month there will be no density caps, and masks will only be mandatory at certain high-risk settings.

But how do we know when is the right time to lift restrictions and what can we learn from countries that have been this way before?

Also on today's show:

* Surgical masks give me "mascne" so I was going to invest in some 100 per cent silk reusable masks that are less likely to cause breakouts. They have a cotton interior but do you think they'd be effective enough against Delta?

* When a zero-COVID state opens up with hopefully high vaccination rates, will it be more vulnerable because there is no natural immunity in the community from infections?