"No-one who has died has had both doses of vaccine."
Of the new cases reported on Thursday, at least 45 were infectious in the community.
It is NSW's worst day of the pandemic so far.
The premier said the Hunter and Upper Hunter region would go into a one-week lockdown after virus fragments were detected in the local wastewater system and positive cases were detected overnight.
The lockdown - which began at 5pm Thursday - applies to the Newcastle, Lake Macquarie, Maitland, Port Stephens, Cessnock, Dungog, Singleton and Muswellbrook local government areas.
The rules mirror those of Greater Sydney, where everyone must stay home except for essential reasons.
Five people were confirmed to have COVID-19 in the Newcastle area on Thursday, including four cases recorded after the most recent reporting period.
The source of infection for the cases is under investigation but is believed to be linked to a gathering at Blacksmith Beach, south of Newcastle on Friday.
Chief Health Officer Dr Kerry Chant stressed that investigations were still in their initial stages.
There are also now nine confirmed cases of COVID-19 on the Central Coast, eight of which live in the same household. Authorities are still investigating the source of those infections, while the ninth case is linked to known cases in the Newcastle area.
Several regional schools Maitland Christian School near Newcastle, Morisset High at Lake Macquarie and Lake Munmorah Public School on the Central Coast - have been temporarily closed over COVID-19 cases.
Aome sewage detections of the virus have also been found in Armidale and Dubbo.
"We're very concerned about regional New South Wales and that's why we've got restrictions in place," Dr Chant said.
"No-one can be complacent."
NSW to receive an extra Pfizer
Dr Chant on Thursday again encouraged NSW residents to get vaccinated, as she said there were 290 COVID cases in hospital and 251 people in intensive care.
"We are seeing young people in ICU," Dr Chant said.
"We are seeing people in their teens, in their 20s and their 30s, as well as older individuals.
"Now is the time to strongly consider getting vaccinated if you're over 18."
Ms Berejiklian welcomed the news that the state would be receiving a fast-tracked supply of almost 185,000 Pfizer doses.
Up to 40,000 Pfizer doses which were taken from the regions to inoculate Year 12 students will be replaced in the week of 16 August.