Health authorities have expressed cautious optimism that Australia is flattening the coronavirus curve, with Chief Medical Officer Brendan Murphy saying he is “increasingly confident” the country will avoid crises happening in countries like Italy and the United States.

Now Australia has to decide what the next steps should be in the effort to end the outbreak, according to University of Melbourne epidemiologist Tony Blakely.

Speaking to, Blakely said Australia has three options.

The first is to impose a stricter lockdown for up to three months, shutting down more businesses and prohibiting people from leaving their neighbourhoods to allow more precise contract tracing. However, he said it might be too late for the government to adopt this choice.

The second option is to ease and tighten restrictions periodically, following fluctuations in the number of new reported infections for up to 18 months. It would require Australians to endure a different lifestyle until a vaccine could be found.

The third option is to develop “herd immunity”, where infections would be allowed to rise in a controlled way until 60 per cent of the population contracted the coronavirus, so that they would later become immune and inhibit the virus from spreading any further. The virus would be concentrated on young and healthy people, and those who got sick would receive the appropriate health care.

“If you manage the virus in this way, you could develop herd immunity in six months,” Blakely said.

It is yet to be known if people could catch the coronavirus twice. There have been reports of reinfection in Japan and China, although researchers suspected there may have been flaws in the testing process.

“This is going to be brutal … Whatever we do, we should do it as a social collective, and make a decision on how we respond,” Blakely said.

“This is the most important decision Australia’s had to make since World War II.”

This article originally appeared on Over60.