Many people see a coronavirus vaccine as a "get out of jail card" but will it really be the solution many hope it is?
The Covid-19 pandemic has stopped the world in its tracks. There's limited international travel, many are confined to their homes and masks have become a familiar sight.
These measures have been put in place until a vaccine is developed, which many hope will make these restrictions unnecessary. Millions have pinned their hopes on life returning to normal once a successful vaccine is released.
"In places like Australia where we are living in mixed elimination, suppression land, that's not the end game," Melbourne University epidemiologist Professor Tony Blakely said. "That's not normal living, it's just a holding place."
Ultimately there's a hope for a return to life pre-Covid and many people think this will happen once a vaccine is developed.
Blakely told news.com.au that it depends on how good the vaccine is.
If a "perfect" vaccine is developed that's more than 90 per cent effective and sees more than 90 per cent of the population get vaccinated — providing herd immunity — this would effectively be the "get out of jail card", Blakely said.
However, if the vaccine wasn't that effective — so only 60 per cent develop immunity because if it, and there were some side effects that discouraged people from wanting to get vaccinated — then it may only provide protection for 50 to 70 per cent of the population and there would be ongoing infection and Covid deaths.
"It would help us, and it's much better than no vaccine but once you open borders you would still be affected by the outbreak, although there would be a lower mortality rate," Blakely said.
Already there have been surveys showing only 68 per cent of Australians would get a Covid-19 shot if a vaccine became available.
The fewer people who are willing to get vaccinated, the more effective a vaccine needs to be to achieve herd immunity.
A third scenario emerges if the vaccine isn't successfully developed or takes too long.
"If in two years, it looks like it's going to be another two years, people might feel they can't keep waiting," Blakely said.
At that point a decision may be made to open borders and rely on better treatments, some of which already reduce the fatality rate by 50 per cent. Better ways to protect the elderly or vulnerable may also be refined.
There's also uncertainty around when Australians will be able to access any successful vaccine with global demand likely to outstrip supply.
A fourth option, which Blakely doesn't believe is likely, would be for better testing to be developed to identify infections more accurately at borders.
"This would make us better at keeping the virus out and squashing it," he said.
While Blakely thinks the possibility of an effective vaccine is far from certain, it's not an issue he believes Australia should be focusing on right now as it grapples with outbreaks in Victoria and NSW. He believes it may be more productive to reassess in two to three months once progress on a vaccine would also be more clear.
There have been some promising developments this week, with reports that one potential vaccine has produced an immune response in all the volunteer candidates in Phase 1 of the study.
Without a vaccine Australia's options certainly appear to be limited.
During an interview with A Current Affair on Thursday, host Tracy Grimshaw grilled Australian Prime Minister Scott Morrison on what would happen if a vaccine wasn't developed.
"Well you keep washing your hands, you keep your one and a half metres distance," the Aussie PM answered.
"You keep your health systems capacity up and strong. You keep opening your businesses. You keep ensuring that people book and sit at tables. That's what you do. You run your country. You run your society in a Covid safe way."
Pressed further on international travel and when Australians would be able to travel to Europe, the PM admitted "the opportunity for large-scale travel beyond our borders is not foreseeable".
Morrison said focusing on scenarios where a vaccine was never developed means "your head is to the floor".
"When your head is to the floor, you can't see what your opportunities are ahead. And that's where I need Australians heads. I need them looking up," he said.
"I need them looking forward because when they're doing that, they're going to be encouraging each other. They're going to be opening their businesses. They're going to be doing whatever it takes to try and keep people in jobs.
"They're going to be doing courses because they believe and rightly that there's going to be an opportunity because that's how Australia works. We will crack this. And whether there's a vaccine, which I believe there will be and I hope there will be, or not, then we will deal with whatever circumstance confronts us, because that's what Australians do."
While Blakely supports the Morrison Government's strategy to contain the virus in Australia, he said in six months time there may be a possibility Australia will be looking to places like the United States and the United Kingdom with envy.
"At the moment they are just hopeless, the US are doing herd immunity by stealth and chaos, it's carnage," he said.
But if 30 per cent of people were gradually infected, which would not provide full immunity but would help, and people continued to wear masks, they may be able to get back to functioning normally.
"I still think doing elimination for as long as possible is better," Blakely said, adding that it made sense for an island continent like Australia.
"But if a vaccine doesn't arrive soon and other countries have partial immunity, they can get back to normal and we won't be able to. They can go to the Olympic Games and we won't.
"Every country is finding their own path out of this, there is no right answer."