However no locally-acquired infections were reported for a 43rd straight day.

According to the state government, there were 735 international arrivals in quarantine hotels by 11pm on Friday, including 55 with symptoms or complex health needs at the Novotel "hot hotel" in Melbourne's South Wharf.

The five cases reported on Saturday - two males in their 30s and 50s and three females in their 20s, 30s and 50s - were uncovered from 8737 tests.

They are obliged to remain in hotel quarantine until they have both tested negative and been cleared by officials.

Deputy Chief Health Officer Professor Ben Cowie told reporters on Saturday symptomatic and non-symptomatic arrivals are separated almost immediately at the airport, with major precautions in place for those who are symptomatic.

He said some 2000 tests of hotel quarantine staff had already taken place.

"Our hotel quarantine system was designed on the premise we would have returned travellers testing positive," Prof Cowie said.

"Detecting positive cases actually demonstrates the system is working and doing what it's supposed to do.

"All steps are being taken and all resources are being mobilised to ensure to the best of our ability those numbers we see remain only in the hotel quarantine program, and furthermore, that those people are given the absolute best standards of health care and support they need."

Meanwhile, Business Victoria says 40,000 vouchers offered as part of the first round of the state's Regional Travel Voucher Scheme have run out.

Holiday-goers hoping to snap up one of the Victorian government's $200 regional tourism offers prompted the application website to crash within minutes on Friday morning, having opened at 10am.

Those intending to spend two or more nights in regional Victoria between Saturday and January 22, 2021 were able to apply.

Business Victoria said the website received 800,000 visits by Friday at 5pm.

Eligible destinations under the $28 million scheme, announced as part of a $300 million state budget tourism package last month, include the Yarra Valley, Mornington Peninsula and Bellarine Peninsula.

"If those $200 vouchers mean people stay an extra night, maybe go to a local pub or restaurant. That's all about wages and spending and investment," Premier Daniel Andrews said on Thursday.

While the first round of vouchers is exhausted, a second application window will open for trips between January 27 and April 1. A third round will be available between April 6 and May 31.

Opposition tourism spokeswoman Cindy McLeish labelled the launch a "flop".

Australian Associated Press