Canberra, Nov 26 (IANS): Australian Prime Minister Scott Morrison will send letters to citizens urging them to book their coronavirus booster vaccines as soon as possible, as the country is still battling the third wave of the pandemic.

In the letter to every Australian home, Morrison said booster shots were the key to keeping Australia open and avoiding a deadly fourth wave of Covid-19 infections, reports Xinhua news agency.

"Thanks to the high vaccination rates, we are now reopening, our economy is strongly re-emerging, and people can get back to seeing family, travelling and living a more normal life," he wrote.

"An important part of this process is ensuring that every person in Australia has access to vaccine boosters to help maintain the best possible defence against serious illness or death," said Morrison.

"Everyone in Australia is encouraged to take up the vaccine boosters to make sure we can keep each and every one of us safe."

Every Australian aged 18 and over is eligible for a booster vaccine six months after their second jab.

Australia on Friday reported more than 1,600 new locally-acquired coronavirus infections and seven deaths.

Till date, 92 per cent of Australians aged 16 and over have received one Covid-19 vaccine dose and 86 per cent were fully inoculated.

Federal Health Minister Greg Hunt on Friday confirmed Australian authorities are working with the World Health Organization to investigate a new variant that was found in South Africa.