Sydney's Bondi COVID-19 outbreak is moving fast, but not as fast as other clusters the city has experienced during the pandemic.
The Bondi cluster stands at 36 cases as of 11:00am today.
The ABC analysed the first nine days of three clusters: the current outbreak in Bondi, the Avalon cluster last Christmas, and the Crossroads Hotel cluster that sparked NSW's second wave last year.
It showed that the Avalon cluster took off at a faster rate than the Bondi outbreak, driven by a super-spreader event at the Avalon Beach RSL Club, and subsequent cases at the Avalon Bowling Club.
That cluster eventually reached 151 cases before it ended in January.
Today is day nine of the Bondi cluster, on the same day the Avalon cluster had reached 119 cases, and the Crossroads Hotel cluster was at 51 cases.
Catherine Bennett, chair of epidemiology at Deakin University, said the Bondi outbreak was similar to the Crossroads outbreak, which started with "an initial landing" and very quick spread.
The Bondi outbreak is being driven by the Delta variant of COVID-19, which was first detected in India but has since spread throughout the world.
The strain is more infectious than other variants and has resulted in people being infected in Bondi after only fleeting contact with COVID cases.
Professor Bennett said the higher infectiousness of the Delta variant did not mean the outbreak was out of control, or was uncontrollable.
She said that unlike the recent outbreak in Melbourne, the Sydney outbreak was still at only the second generation of spread.
"That brings the real footprint of the case numbers back down to something more manageable in terms of the people they don't know about or might have been out and infectious," she said.
The Melbourne outbreak was at the fourth or fifth generation before the first cases were identified.
However, she said the worst case scenario for the current outbreak was "a bad luck situation".
"That is more likely to happen with this virus because it does give you a higher viral load and if that person is a good shedder of the virus and is also out and about. Put those three things together and it just means the spark is a bigger spark," she said.
NSW Premier Gladys Berejiklian announced a raft of new measures in Sydney to contain the outbreak, including restricting the movement of people in seven local government areas.
In Parliament yesterday she would not rule out a lockdown for Greater Sydney.
"The New South Wales government will not hesitate to go further and harder if we have to," the Premier said at Macquarie Street.
"And I really want the public to be prepared. We've not experienced this level of transmissibility in this variant previously and it has no doubt impacted our response."
