The new cases, confirmed by the Department of Health on Friday, brings the number of cases linked to the Whittlesea cluster to 30.

There were also two new cases in hotel quarantine, bringing the total number of active cases in the state to 39.

A record 47,462 Victorians were tested in the 24 hours to Friday morning, while 17,223 received a dose of the COVID-19 vaccine.

“The vaccine is really our only ticket out of this,” Health Minister Martin Foley said.

From Friday, Victorians aged 40 to 49 are eligible for the Pfizer vaccine.

The seven-day, statewide shutdown kicked in from midnight after a cluster of 26 cases of the Indian variant of the virus emerged in Whittlesea in Melbourne’s north.

More than 14,000 primary and secondary contacts are self-isolating and there are more than 150 exposure sites across Melbourne and regional Victoria.

New additions to the list include RMIT University buildings, Coburg’s Pentridge Cinema and various sites within Southern Cross Station.

It comes as Victoria’s mass vaccination centres will begin administering Pfizer shots for anyone aged 40 to 49 on Friday.

The state’s coronavirus hotline was inundated with calls immediately after it was announced vaccination eligibility would be broadened, with some people on hold for hours trying to secure an appointment.

The health department said it was flooded with more than 77,000 calls in a 15-minute window before “technical issues” were resolved.

But there are reports the phone line was again down on Friday morning.

The latest outbreak, seeded in South Australian hotel quarantine, has again raised questions about the capability of Victoria’s contact tracing system, which was partially blamed for the state’s second 112-day lockdown.

But Chief Health Officer Brett Sutton said it was “absurd” to suggest contact tracing was failing.

The lockdown is set to end at 11.59pm on June 3, although Acting Premier James Merlino said it could end earlier.

He said he had faith in the state’s contact tracing team but the virus was “running faster than we have ever recorded”.

People can only leave home for five reasons: to shop for food and essential items, to provide or receive care, for exercise, work or study, or to get vaccinated.

Victorians must observe a five-kilometre travel limit for exercise and shopping, and compulsory wearing of masks both indoors and outdoors.

All non-essential shops are closed but essential stores such as supermarkets, bottle shops and pharmacies remain open, with shopping limited to one person per day, per household.

Cafes and restaurants can only offer takeaway.

Childcare and kindergarten facilities will stay open but schools are going back to remote learning for most students. State-run schools are having a pupil-free day on Friday to prepare for the switch.

Meanwhile, Coles and Woolworths have imposed a limit of two packs of toilet paper per person after shoppers rushed to stock up.

“We have plenty of stock in our supply chain, and this temporary measure will help us to manage demand so that we can return our stores to a fully-stocked position as quickly as possible,” Coles said in a statement on Friday.

The lockdown is expected to cost Victorian businesses up to $1 billion.

Federal Health Minister Greg Hunt on Friday confirmed the Commonwealth would not provide any financial support to affected businesses.

“At this stage, Victoria is the responsible body they have said that they will be providing additional support,” Mr Hunt told ABC Radio National.

“This is a difficult time, and I’ll leave those matters to the treasurer, but the Victorian government has indicated that they will be taking those measures.”

The ABC is reporting the state government will annouce a $200 million package to support small businesses in Victoria.