CANBERRA (REUTERS, BLOOMBERG)) - Australia said on Sunday (Dec 12) it will shorten the waiting time for people to receive Covid-19 booster vaccines following a rise in cases of the Omicron variant.

Australia had previously said it would offer a Covid-19 booster to everyone over 18 and who had their second dose of the vaccine six months prior.

But with rising cases of the Omicron variant, Australia's Health Minister Greg Hunt said the time interval will be shortened to five months after the second dose.

The move to reduce waiting times means some 1.5 million people will be eligible for a booster starting Sunday, the Herald Sun newspaper said.

"A booster dose, five or more months after the second dose, will make sure that the protection from the primary course is even stronger and longer lasting and should help prevent spread of the virus," Mr Hunt said in an emailed statement.

"Data from Israel shows boosters supporting reductions in the rate of infection in eligible age groups, severe disease in those aged over 40 years and deaths in those over 60 years."

Australia will use both vaccines from Pfizer and Moderna in its booster programme.

Australia is one of the most vaccinated countries, with about 90 per cent of people over 16 fully inoculated.

The country's most populous state, New South Wales, saw the pace of new cases decline for the first time in six days. The state said Sunday there were 485 new infections, versus 560 reported Saturday.

There are 55 Omicron variant cases in New South Wales, after 10 were confirmed overnight, and more are expected as results of genomic testing are confirmed, the government said.

Victoria state said it recorded 1,069 additional cases, down from 1,193.