I can't help but think there are other options that should be on the table. Such as using Howard Springs exclusively for unvaccinated travellers (and later Vic/Qld facilities), and keeping HQ for those who have been vaccinated (this might need some support, for countries where difficult to get vaccine).
There seems to be increasing evidence that the vaccinated are less infectious (see below), so
1) You have a negative test of someone who is vaccinated.
2) They are less likely to get it during transit/last few days before departure.
3) If they do get it they are less likely to pass it on
4) The people they are likely to pass it on to (other HQ inmates and the staff) are also all vaccinated thus less likely to get it HQ from someone who is less likely to transmit it...
The risk seems to go much lower this way. Or am I missing something?
Since vaccines began rolling out across the world, many scientists have been hesitant to say they can reduce transmission of the virus.
www1.racgp.org.au