The number of casual contacts linked to a coronavirus case in northern Tasmania has grown as authorities ramp up testing and vaccination efforts in the region.
The 15-year-old boy, the island state's second case this year, breached home quarantine in Launceston on Saturday afternoon while infectious to go to an IGA supermarket.
Seventeen of his close contacts, who are all in quarantine, have since returned negative tests and will be tested again in coming days.
Acting Premier Jeremy Rockliff announced on Thursday the number of casual contacts linked to the case had risen from 35 to 51.
Seven of those cases, mostly people who were at Launceston Airport when the boy flew in from Victoria on Friday and those at the IGA, have also tested negative so far.
State Public Health Director Mark Veitch said it remained possible one of boy's close contacts would test positive.
"We're at that time when we could see cases among contacts, which is why we do another round of testing of the closest contacts over coming days" he said.
The boy, who is staying in a Hobart medi-hotel with his dad, has the more contagious Delta strain of the virus.
Mobile testing and vaccination clinics will be rolled out in Launceston's northern suburbs in coming days.
"I'd like to encourage everyone, especially in the Launceston community, even if you have the mildest symptoms, come forward and get tested," Mr Rockliff said.
"Even if you are vaccinated, you need to get tested if you have symptoms."
Mr Rockliff said Tasmania was on track to pass the 80 per cent first dose milestone for the 16-and-over demographic this weekend.
As of Wednesday, more than 62 per cent of eligible Tasmanians are fully vaccinated.
A plan to bring a vaccination bus to small towns with lower jab rates will be detailed in coming days.
The state government, which is expected to reveal its reopening plan in coming weeks, has previously said it won't ease border restrictions until all Tasmanians have had the chance to be vaccinated.