Premier Gladys Berejiklian on Monday announced around a million people in that age bracket could get a Pfizer COVID-19 jab at the new purpose-built vaccination hub at Sydney Olympic Park within weeks.

Those keen to roll up their sleeves were encouraged to register their interest with the government from 5pm on Monday.

Ms Berejiklian on Tuesday said the call-out had received an overwhelming response in 18 hours.

"I was thrilled to learn that we have about 62,000 people who've already registered for the Pfizer jab," she told 2GB.

The premier also revealed the new government-run Homebush hub had doled out 2500 vaccines in it's first day of operation, about a third of all vaccines administered across the state on Monday.

For the first two weeks, the vaccination hub will be open to people in categories 1a and 1b - emergency and aged care workers, frontline workers and their families.

From Wednesday, anyone 50 or older can register to get the AstraZeneca vaccine at the hub from May 24.

Meanwhile NSW Health is on high alert after a Victorian man tested positive to the virus after a two-week hotel quarantine stint in South Australia.

The man was active in the Greater Melbourne area for several days.

Anyone in NSW who has been in the Melbourne area since May 6 must complete a declaration form, available on the Service NSW website, confirming they have not attended a venue of concern, NSW Health says.

If they have attended any of the venues identified at the times listed, they must contact NSW Health immediately.

It comes as NSW contact tracers search for the 'missing link' that infected a Sydney man who was diagnosed with the virus last week.

Australian Associated Press