Victoria is on tenterhooks with 11 new cases of coronavirus including nursing home residents and staff, stoking fears lockdown may continue beyond seven days.

It emerged on Monday the federal government scrapped a requirement for aged care workers to only work at one facility in November last year.

Despite Victoria’s concerning outbreak, the rule wasn’t reinstated until the Commonwealth designated Melbourne as a coronavirus hotspot on Thursday.

Health Minister Greg Hunt said about 4.7 per cent of aged care staff had worked across multiple sites as he stressed the importance of flexibility in periods without outbreaks.

He said case numbers were the main factor in determining whether the single-site rule was in place.

“That is something that has been well established in consultation with the states, and so once that was reached then the definition was triggered,” Hunt said.

Labor’s health spokesman Mark Butler was scathing of the decision to lift the ban in November.

“This latest outbreak in aged care is a direct result of Scott Morrison’s gross negligence and dangerous complacency,” he told reporters in Canberra.

“If today’s events don’t convince Scott Morrison and his ministers that a speedy, effective vaccine rollout is a race, a race against this virus, a race against the variants of this virus, in particular, I don’t know what will.”

Hunt said a vaccinated 99-year-old woman, who is now in hospital, had contracted the disease at the Arcare home in Melbourne’s west but had not shown symptoms.

A second resident, 95, has been retested on medical advice.

Of Australia’s 910 coronavirus deaths, 685 have been aged care residents.

More than 4.2 million vaccine doses have been administered, a target the government initially set for March.

Health secretary Brendan Murphy, Chief Medical Officer Paul Kelly and Aged Care Services Minister Richard Colbeck are set to face questions about the outbreak during Senate estimates on Tuesday.

Hunt has asked Professor Kelly and the expert medical panel to revisit its advice from January that vaccinations should not be mandatory for aged care workers.

“That was not recommended at the time and we have asked the medical expert panel to review precisely that question,” he said.

Friday’s national cabinet meeting of Morrison and state and territory leaders will consider the fresh advice.

-with AAP