Infected aged care worker 'exactly what you don't want to happen', expert says

Victorian contact tracers are today continuing their urgent investigation into how an aged care worker who tested positive to COVID-19 became infected with the virus.

The ability of health authorities to identify the missing link will be "critical" in controlling the spread of the virus, Professor Catherine Bennett, chair of epidemiology at Deakin University, told Today.

"We always worry if we haven't got that link," she said.

READ MORE: Growing COVID-19 exposure sites worry health experts

"Having someone not knowing they are infectious at work in aged care is exactly what you don't want to have happen.

"The fact is we have got people who are not all vaccinated, only 50 per cent of the residents, who are vulnerable now with the virus inside the aged care."

So far, 40 people have been linked to the cluster in the city's north and more than 4000 people have been identified as primary close contacts.

READ MORE: Victoria launches blistering attack over COVID-19 support

Meanwhile, the list of exposure sites has grown to beyond 270.

Professor Bennett said the situation should serve as a warning to the rest of the country about the importance of a speedy vaccination process.

"Waiting comes with a cost. I think that's what we are learning now," she said.

"Unfortunately it might take something like this to help people understand this is not an abstract possibility, that this is real and you won't know it's happened until it is too late."

Melbourne's latest outbreak has seen a sharp rise in the number of people coming forward to get the COVID-19 jab with vaccine centres overwhelmed with people.

"I think people persevering with the delays and trouble booking is really important," Professor Bennett said.

"Getting those numbers up is critical and that will help us over the next few weeks."