Victoria has recorded 21 new locally acquired COVID-19 cases.

Health officials say they are all linked to previously reported infections and 11 were in quarantine during their entire infectious period. The state now has 163 active cases, three in hospital including one in ICU.

Victoria administered 29,490 vaccine doses in the 24 hours to Friday evening, a record, and conducted 33,675 tests for the virus during the same period.

Meanwhile, Australia’s biggest mall, Chadstone shopping centre in Melbourne, has been declared a tier two COVID-19 exposure site.

Anyone who was at Chadstone between 4.26pm and 5.40pm on Saturday August 7 must take a virus test and isolate until they receive a negative result.

The Coles supermarket within the shopping centre has also been listed.

There are now more than 450 exposure sites in Melbourne including Highpoint shopping centre and several large apartment blocks.

Health Minister Martin Foley says with virus cases in multiple Melbourne suburbs, more vaccination centres will be opened.

“We’re expanding the capacity of existing centres with more booths and our booking system is constantly, as more supply comes on board, being updated to accommodate new supply,” he told reporters on Saturday.

“To further meet the increased demand that we’re seeing from Victorians to come forward and get vaccinated, we will be establishing more drive-through sites, particularly in the north in the Wyndham area, in Melbourne’s southeast and in the north in the Hume Whittlesea area.”

Victoria’s deputy secretary of contact tracing, Kate Matson said there were more than 14,000 primary close contacts across Victoria related to the current outbreak.

Some 650 close contacts had been cleared over the past couple of days while the state’s household engagement program had conducted a record 1277 visits on Friday.

Ms Matson said there were still eight mystery cases being investigated.

Victoria’s Chief Health Officer Brett Sutton on Friday highlighted the lockdown’s ongoing “heartbreaking” toll on children, as the mystery cases threatened to further extend shutdown.

Professor Sutton said he considered the social impacts of lockdowns when providing health advice to the state government, including keeping children out of school and away from their friends.

“It’s heartbreaking,” he told 3AW of having to explain that fact to his own three young children.

“But, again, what alternative pathway have we got available to us? Because we know what happens when restrictions are not done in a timely way or are not sufficient to control transmission – it explodes in numbers.”

Melbourne is in the second week of its sixth lockdown, brought on to contain several Delta variant outbreaks.