The five million people living in lockdown in Sydney and surrounds should learn on Wednesday whether their confinement will extend beyond two weeks.
Premier Gladys Berejiklian said on Tuesday she would be consulting with health experts throughout the day and into Tuesday evening, with hopes of telling the community on Wednesday "what next week looks like".
NSW recorded 18 new COVID-19 cases in the 24 hours to 8pm on Monday, with seven in the community for at least some of their infectious period, bringing the total number of people infected in the latest outbreak to 330.
It's a significant drop from the 35 cases the previous day and the premier says "the lockdown is having its desired effect ... but it's still concerning that a number of cases are remaining infectious in the community for that period of time".
The stay-at-home orders for more than five million people in Greater Sydney, Wollongong, Shellharbour, the Central Coast and the Blue Mountains regions are due to end at midnight on Friday.
Ms Berejiklian said the length of the lockdown will be informed by the fact the NSW government wants this to be the state's last lockdown.
"We intend for this lockdown to be the only lockdown we go through," she said.
She warned that due to the virulence of the Delta strain, restrictions may persist after the lockdown ends until a good majority of the population is vaccinated.
"I anticipate that when we do come out of the lockdown it won't be what life looked like necessarily before we went into lockdown," Ms Berejiklian said.
Sixteen of the new cases were linked to a known case or cluster, including nine household contacts of previous cases. Two cases are still under investigation.
Chief Health Officer Kerry Chant said about 80 per cent of the population needed to be vaccinated "as swiftly as we can ... (but) the constraint is supply".
There were 32,136 tests on Monday - down from more than 58,000 on Sunday and Dr Chant urged more people to get tested.
"I'd like to see over 40,000 tests every day this week to give us the best assessment that we are not missing chains of transmission," she said.
Meanwhile, it's been revealed that 160 students from Sydney's exclusive St Joseph's College received their first dose of the Pfizer vaccine in May, despite it not being available for younger people or the general public.
The school issued a statement saying it approached Sydney Local Health District because the boys are boarders with some coming from rural communities, including remote Indigenous communities.
Sydney Local Health District chief executive Teresa Anderson on Tuesday said only Indigenous students - who are eligible - were supposed to be vaccinated.
"Through an error, the wider group of boarders in Year 12, a total of 163 students, were also vaccinated," she said.
"Sydney Local Health District apologises for this error."
Meanwhile, a third worker at the SummitCare aged care facility at Baulkham Hills in Sydney's northwest is among Tuesday's new cases, sending more staffers at the home into isolation.
The staffer worked while infectious but had received their first dose of AstraZeneca and did not expose any more residents.
Five SummitCare residents have tested positive, including one who was not vaccinated. All five have been sent to Westmead Hospital for observation.
Another of the new cases is linked with the Meriton Suites Waterloo cluster.
Eight to ten people attended a party there on June 26, the first night of lockdown. Seven of the revellers have now tested positive, as well as five household contacts.
Meanwhile, 13 NRL St George players have been fined for attending a party at the home of Paul Vaughan, who was sacked by the club for hosting the gathering on Saturday night.
Elsewhere, NSW Health has issued fresh alerts including for people who dined at The Locker Room at Sydney Olympic Park, Club Marconi at Bosley Park, JB Hi Fi at Westfield Bondi Junction, Marrickville Metro Shopping Centre and Woolworths Metro Granville.
NSW Health said there were 26 COVID-19 cases in hospital, with six in intensive care, two of whom require ventilation.
The two-week lockdown in NSW is expected to cost the economy about $750 million a week or more, according to St George Bank economists.