Federal government figures released on Thursday show 52.2 per cent of the eligible population aged 65 and over have received their fourth jab, equating to more than 1.6 million people.

That was up 1.6 per cent on the same time last week.

In total and accounting for those aged under 65, more than 1.8 million Australians have received at least four vaccine doses.

People become eligible for their winter booster four months after their third dose.

Authorities continue to urge people to take up boosters and influenza vaccinations to help protect their families this winter.

Federal Health Minister Mark Butler issued a reminder on Thursday, coinciding with his announcement that children between 12 and 15 who are most at risk of severe disease can get their boosters from Tuesday.

To be eligible, children have to be severely immunocompromised, have a disability with significant or complex health needs, or have complex and or multiple health conditions that increase their risk of severe COVID-19.

One or multiple of those categories can apply to children for them to be eligible.

Meanwhile, Victorian Opposition Leader Matthew Guy has tested positive for COVID-19.

In a tweet on Friday morning, Mr Guy said he had head cold symptoms but was feeling OK.

LATEST 24-HOUR COVID-19 DATA:

NSW: 7551 cases, 11 deaths, 1250 in hospital with 41 in ICU

Victoria: 8025 cases, 19 deaths, 512 in hospital with 28 in ICU

Queensland: 3786 cases, one death, 301 in hospital with nine in ICU

Tasmania: 681 cases, no deaths, 32 in hospital with one in ICU

SA: 2342 cases, two deaths, 235 in hospital with five in ICU

WA: 7174 cases, six deaths, 279 in hospital with 16 in ICU

NT: 213 cases, no deaths, 13 in hospital with none in ICU.

Australian Associated Press