As NSW stares down its latest Covid-19 cluster, a leading epidemiologist has warned Sydney could be "in trouble" if restrictions aren't imposed in a timely fashion.
UNSW epidemiologist Mary-Louise McLaws has called for vigilance and restrictions to be brought in after the cluster grew to three known cases on Thursday.
While the northern Sydney beaches cluster before Christmas last year grew to more than 120 cases before health authorities managed to suppress the outbreak with localised restrictions, Prof McLaws' concern is largely about the more infectious variant that has made its way to Australian shores.
"We're in trouble, now we know the strain is Delta," she told the ABC.
"The restrictions need to be [introduced] strictly and quickly because this virus has learnt how to be highly infectious and doesn't need a lot to spread."
The Delta variant, which has been circulating in Melbourne along with the Kappa variant, is listed as a variant of concern by the World Health Organisation. Prof McLaws is an adviser to the global health body.
"It's up to 70 per cent more infectious than other strains, so it's very problematic," she said.
The only mandatory requirement brought in since the eastern suburbs outbreak this week is the wearing of masks on public transport in the greater Sydney region from 4pm Friday for the next five days, while masks are strongly encouraged for indoor settings such as cinemas and shops.
New Delta variant highly infectious
In the UK, spread of the Delta variant forced the country's prime minister Boris Johnson this week to delay the easing of restrictions after earlier announcing a roadmap out of lockdown.
Victoria's health authorities did not hide their concern of the more infectious strain in recent weeks but appear to have almost eradicated it after a complete two-week Melbourne lockdown.
The variant has made its way into the community via leaks from hotel quarantine systems in multiple states, with Prof McLaws previously telling Yahoo News Australia Scott Morrison's claim hotel quarantine was 99.9 per cent successful was meaningless.
"The only way they’ve gotten through is the failures of the program. That does not tell me that it’s 99.9 per cent perfect at all," she said.
Health officials under pressure over staff vaccinations, testing
The cluster was sparked on Wednesday night when an unvaccinated limousine driver from Sydney's eastern suburb of Bondi and his wife were diagnosed and a woman in her 70s was subsequently infected at a Vaucluse cafe frequented by the couple.
The man from Bondi transports international flight crews and police are investigating if he breached any health orders, which require those working around the hotel quarantine system to be tested for the virus daily and wear personal protective equipment.
With state health authorities under pressure over what critics say was a preventable infection, NSW Health Minister Brad Hazzard said there was an expectation but not an obligation for people working on the Covid-19 frontline to be vaccinated.
"There has been a reluctance through national cabinet to have mandatory testing," he told ABC's 7:30 program on Thursday night.
"But it's certainly something which ... we're now looking very closely at.
"So, I've asked our lawyers to give us advice on that. And we'll be making some decisions shortly."
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