An employer can only mandate workers be vaccinated when public health orders have been made that require those workers to be vaccinated.
Outside of this, it is unlikely that requiring workers to be vaccinated will be reasonably practicable.
Employers must consult with workers and HSRs at the workplace prior to any decision on mandatory vaccinations.
If you are told that vaccination is compulsory in your workplace,you should ask for any instruction from management to be put in writing and request any relevant supporting policy to back up the instruction. Following this, contact the AMWU for advice.