South Australia is talking to the freight industry about making COVID-19 vaccinations a requirement for interstate truck drivers.
SA Chief Public Health Officer Nicola Spurrier flagged the issue on Tuesday while advising a truck driver from NSW tested positive travelling through the state on September 2-3.
The government will later on Tuesday update its list of exposure sites to likely include a BP service station at Wingfield visited by the driver late last week.
"This is a risk for us in South Australia," Professor Spurrier said of truck drivers entering the state by road.
The NSW driver was picking up and delivering timber and it's understood his interactions in SA were mostly contactless.
Prof Spurrier said she believed the risk of any transmission of the virus was "very low".
On the vaccination of drivers, Prof Spurrier said the government was working hand in hand with the freight industry on this issue.
"We need to make sure there are vaccines available to make it as easy as possible to get vaccinated," she said.
One option was setting up vaccination clinics on regional roads for drivers to access.
Meanwhile, the SA government has announced a mass vaccine hub at Wayville in Adelaide will be expanded to 96 bays, from 42.
This means an extra 35,000 appointments will be available to residents from now to the middle of October.
South Australians have received 1.3 million doses of COVID-19 vaccines through mass clinics, federal programs and GPs.
"We know we have probably done more than we originally anticipated through the mass vaccine clinics," Premier Steven Marshall said on Tuesday.
"People have found it very, very convenient."