Here is some background material on the US situation on whether of not mandatory Covid-19 vaccinations would be constitutional. The answer is, probably not, given the extensive protection of liberties in the US constitution. But, the situation is different for Australia, which has a constitution mainly serving as an enabling document, to get the Federation up, and commerce flowing. Liberties were supposed to be protected by the common law, and parliament. The idea that the parliament and the courts could become corrupted, did not occur to the constitutional framers, and one cannot be too hard on them, since what has happened is the equivalent of say an invasion form space by real aliens, happening today. It just was not in their paradigm. Thus, we have the Melbourne situation, and it could get worse. One shudders to think what the state would do if there as a real danger, like a 1918 flu, with bodies on the street. There is a fundamental jurisprudential problem here, as the present system does not protect freedoms in cases where the elites go for broke and set out to enslave us. Perhaps, given the US situation, no set of laws and rules could do this, because all these systems require fair and just operators, and when that goes, there is only the chaos which is dawning now. Law has its limits, limits set by human nature, tainted by original sin.
https://www.youtube.com/watch?v=IfnJi7yLKgE&feature=emb_title
https://articles.mercola.com/sites/articles/archive/2020/08/22/the-great-vaccine-debate.aspx?cid_source=dnl&cid_medium=email&cid_content=art1ReadMore&cid=20200822Z2&mid=DM627865&rid=946086213