I would agree with you that eventually, we would need either "Herd Immunity" or an effective medical treatment (vaccine).
However, I disagree that we have to apply the "Herd Immunity" strategy now.
Our exports are mainly resources - Iron Ore, Coal, LNG and Food. We can control that, as it takes a minimum of 6 weeks before any container docks on our shores - by that time, we would know who amongst the crew are infected. Further, when the ship docks, we can conduct tests when they arrive. IMHO, this sector can go on as normal, with a slight delay caused by testings.
Our other main export is education: we can also control this, by quarantining all students for a minimum of 14 days, whilst we monitor and conduct tests on them. This sector can go on as normal with a bit of adjustments.
That leaves tourism - this sector will probably take a hit in the short term. So we will need to support this sector for about a year.
Any imports via container ships will take a minimum of 6 weeks also.
Other than that, businesses can be conducted per normal as negotiations and contracts can be concluded via video conferencing (can save a record of the meeting for court purposes if any dispute arises).
We are fortunate in the sense that we are an island surrounded by water. This provides a natural barrier against any unwanted intrusion.
As such, I think we can control this, until either a medical treatment is found or a vaccine is developed.
Unlike poorer countries, we don't need to risk the lives of our elderly Australian.
