Victoria has recorded five new local cases of coronavirus as authorities scramble to figure out how a family that travelled to NSW contracted the highly contagious Delta variant of the virus.
Authorities also announced on Saturday morning one extra case in hotel quarantine, as Melburnians entered their second weekend of a snap lockdown.
Three of the five new local cases are primary close contacts of existing cases – however the other two, who have both visited shopping centres in Craigieburn and Epping, are so far unlinked.
One of the new cases was a worker at a building site in Melbourne's CBD. The site has been closed, affecting 170 workers.
The new cases came from 36,362 tests and bring the number of active infections in Victoria to 78. The size of the current outbreak has now reached 70, including one person who has recovered.
It comes as authorities look into how a Victorian family contracted the Delta variant, which was first detected in India and is different to the Kappa variant that sparked the state’s latest outbreak.
The Delta variant cluster is now at nine cases, Victoria's COVID-19 response commander Jeroen Weimar said on Saturday.
The variant, also known as B1.617.2, has been causing devastation in India and Britain, but it has not yet hospitalised anyone in Australia.
It was revealed on Friday that , which has been classified by the World Health Organization as among the four COVID-19 variants 'of concern' due to evidence that they spread more easily.
It remains unclear how those family members, who also travelled to Jervis Bay in NSW, contracted the variant.Sharon Lewin, an infectious disease expert from the Doherty Institute, said on Saturday she had a “strong hypothesis” the Delta variant arrived in Victoria via hotel quarantine.
People seen wearing masks outside Flinders Street Station in Melbourne. Source: AAP
Testing in Jervis Bay has not found any new COVID-19 cases, making it unlikely the variant was contracted in NSW, she said. NSW recorded no new cases in the 24 hours to 8pm Friday.
“It would be most unlikely to have mutated in Australia. We have virtually no transmission here, we have tiny numbers, so it would not have mutated in Australia. It would be a separate importation,” Prof Lewin told reporters.
The family from Melbourne's west has more than 300 close contacts, many of them at North Melbourne Primary School, and authorities suspect there has been transmission between two grade five students at the school.
Up to five close contacts have been identified in public housing towers, which were subjected to a harsh snap lockdown last year to not have been based on direct health advice and to be in violation of state human rights laws.
Health Minister Martin Foley said vaccination rates in public housing were currently "not what we wanted [them] to be" but there has been an uptick of interest in recent weeks.Friday saw 24,263 COVID-19 vaccine doses administered across the state, while anti-vaccination and lockdown protests were held in Melbourne on Saturday.
Police apprehend a man at an anti-vax protest outside Melbourne's Flinders Street Station. Source: SBS News/Abby Dinham
Chief Health Officer Brett Sutton said it was “unfortunate” a "small minority" wanted to prevent people from getting vaccinations, noting that COVID-19 shots are not mandatory.
“It is your choice, but do not get in the way of all of those Victorians who are trying to come and get vaccinated today and every day," he told reporters.
Victoria Police said it arrested two people and issued 16 fines following the protests, 11 of which were for demonstrators travelling outside the 10km from home radius allowed under Melbourne’s lockdown rules.
With AAP.