Pre-flight testing is required for people coming into Australia, but UNSW epidemiologist Mary-Louise McLaws doesn't think it's enough.

"They often have it several days before they hop on the plane," she told the Nine Network on Wednesday.

"Anything can happen between that three day period of having the PCR (test)."

"Then also they may have to transit. They may, of course, inadvertently acquire it there. It's just an additive bundle of prevention."

Australia is on the cusp of having 80 per cent of people aged 16 and older fully vaccinated.

The latest federal data shows 78 per cent are double-dosed, with about 88 per cent partially vaccinated.

NSW has fully vaccinated 88 per cent of its over-16 population as the state accelerates the further easing of restrictions for the double-dosed.

It recorded 190 new cases and four additional deaths on Wednesday.

Victoria's daily new infection tally fell below 1000 for the second day running, with 941 cases and eight more deaths.

It has surpassed an 81 per cent double-dose rate.

The national capital is Australia's most vaccinated jurisdiction, with more than 93 per cent of residents aged 12 and older double-dosed.

It racked up eight more cases on Tuesday.

The Northern Territory and Western Australia are the country's least vaccinated jurisdictions.

Just under 64 per cent people in WA and the NT are double-dosed. Queensland is slightly ahead, with a vaccination rate of nearly 65 per cent.

Pressure has been mounting on states with no infections or low numbers of cases to lift vaccination rates so internal borders can reopen further.

Meanwhile, US manufacturer Novavax has asked the Therapeutic Goods Administration to give its jab the green light.

Should it be approved, Novavax will be the fourth COVID-19 vaccine made available in Australia.

The government has purchased more than 50 million doses expected to form part of its booster shot rollout starting with aged and disability care residents.

Australian Associated Press