A Letter from the Prime Minister Scott Morrison on Vaccination within Australia.

Below is a correspondence from Prime Minister Scott Morrison' on the subject of the vaccination roll out in Australia and another confirmation vaccination is not compulsory within Australia as vaccination is a personal choice. If this is the case why are the States doing indirectly what the Commonwealth cannot do directly?  In respect of this the following question still remains unanswered, Can States law regulate trading corporations contrary to Commonwealth industrial laws and force companies to impose vaccination indirectly by prohibiting unvaccinated employees from entering the workplace?