Advice specific to apprentices about their rights and responsibilities can be accessed from Fairwork Australia.  

General Advice

Employers should discuss available options with staff in order to minimise the impact on their employment, while taking into account advice and/or directions from the Health Authorities.  Medical advice should be sought if in doubt about medical issues and employers should not try to make medical assessments.  The circumstances of each situation would need to be assessed as to the options available and the support that can be provided to employees, while taking into account the needs and capacity of the business.  
FAQ's

What happens if an apprentice or trainee or their family member is sick with Coronavirus COV-ID 19?
If the apprentice is sick with the Coronavirus they may access their sick leave entitlements. If a family or household member of the apprentice or trainee is sick and they need to look after them, they can access carer’s leave. In both these situations the GTO may request evidence to support the leave claim.

What happens if an apprentice or trainee wants to stay home as a precaution?
Unless the apprentice or trainee has a medical condition, they do not have any entitlement to take sick leave. However, the GTO, host and apprentice or trainee may negotiate to take annual leave, RDOs, work from home or take leave without pay. The GTO and host could also agree to approve the use of sick leave.

What happens if an apprentice or trainee is sent home by the host as a precautionary measure, or the host company shuts down for 14 days as precautionary measure?
If the host has adopted a shut-down as a precautionary measure and not related to any direction from the health authorities and there is no evidence of any medical issues applying at that workplace, the apprentice or trainee would need to be paid.They could also be asked to work from home depending upon the type of work they undertake.
What happens if an apprentice or trainee is required to travel for work by host company?
The apprentice or trainee should only undertake travel that is consistent with Health Department guidelines. Please visit https://www.smartraveller.gov.au/news-and-updates/coronavirus-covid-19 regarding the latest update on travel.

What happens if a host’s business is required to close down as a result of the Coronavirus or its supply chain of components and materials has been impacted by the Coronavirus?
This situation may fall under the stand down provisions in S.524 of the Fair Work Act which provides for an employee to be stood-down without pay but only where the employee cannot be usefully employed due to a stoppage of work for which the employer cannot reasonably be held responsible.  If an employee is being stood down under the Fair Work Act they need to be advised that this is the case.  Even though they are not being paid they continue to accrue leave.

Each close-down situation would need to be assessed as to whether it meets the definition of not being usefully employed for a reason outside the employer’s control. There is case law about limits on using stand down provisions – but in general if the Health Department ordered closure of an establishment then this would most likely fall into that definition as it is outside the employer’s control.