Byron Bay, Australia's most easterly town, has also gone into lockdown. Photo: AFP / Andrea Falletta / NurPhoto

Sydney posted a new record of Covid-19 infections Tuesday as the city struggles to control an outbreak that is sending other Australian regions into lockdown.

New South Wales state announced 356 new cases, a fresh record for a Delta-variant outbreak that began in mid-June and continues to grow in a population with low vaccination rates.

More than five million people in Sydney, Australia’s biggest city, are now in their seventh week of lockdown as the cluster hit 5,805 cases with 32 deaths to date.

“Our strategy is to get to as close to zero as we can …  but regrettably we have seen those numbers increase in the last few days,” state premier Gladys Berejiklian said.

The coastal town of Byron Bay became the latest put under stay-at-home orders – joining regional centres such as Newcastle and Tamworth – with a snap seven-day lockdown announced late Monday after an infected person traveled there from Sydney.

Meanwhile, another five million residents of Melbourne are in their sixth pandemic lockdown after a fresh cluster emerged in the city last week.

Australia had dodged the worst ravages of the pandemic through a strategy of closed borders, lockdowns, mandatory travel quarantine and aggressive testing and tracing. 

But those tools appear blunted in the face of the highly transmissible Delta variant and have left Australians weary of repeated lockdowns.

Australia’s glacial vaccine rollout has been one of the slowest in the OECD.

Just over 20% of the population is now fully vaccinated, but the under-pressure conservative government has promised a boost to supplies from September.

Prime Minister Scott Morrison said the country was in a “tough fight” against the Delta strain but he wanted to get “everybody around that table at Christmas time.” 

The nation has recorded about 37,000 cases of Covid-19 and 940 related deaths to date in a population of 25 million.

AFP