Australia’s second-most populous state Victoria reported 190 new locally acquired coronavirus cases, health officials said on Saturday, as the state struggles to contain an outbreak of the highly infectious Delta variant.

Of the new infections, 103 were linked to existing outbreaks, the Health Department said on its Twitter account.

Australia, largely unvaccinated due to scarce supply of Pfizer shots and public unease about the AstraZeneca vaccine, is battling the worst wave of the novel coronavirus so far.

On Friday, it recorded its biggest one-day rise in COVID-19 infections, with 1 657 new cases and 13 deaths, mostly in New South Wales.

Authorities have warned the worst is yet to come,with NSW expected to report more than 1 000 daily case for at least the next couple of weeks, and Victoria’s outbreak to grow.

Victoria, NSW and the Australian Capital Territory, together home to nearly 60% of Australia’s 25-million population, have been under strict lockdown for weeks, which is expected to last until 70% of the population is fully vaccinated.

So far, only about a third of those aged 16 and over have been vaccinated in Australia, although the inoculation pace has picked up considerably as of late, with the federal government racing to secure more Pfizer shots.

At current pace, Australia may reach the 70% threshold in late October or early November.

A total of just above 58 200 cases and 1 032 deaths have been recorded in Australia since the pandemic began, far lower than many comparable countries.

The Delta outbreak, however, has cast doubt on whether it is wise to pursue elimination strategies – used by states and territories successfully in previous waves of the coronavirus pandemic.

“We are not going to be driving this down to zero,” Victoria Premier Daniel Andrews said on Friday.