News this week that Australia could have 25 million doses of the so-called "Oxford vaccine" available by early 2021 raises hope that a way to control Covid-19's spread may not be far away.
But it also raises some serious ethical questions about how the vaccine would be distributed - including whether it should be mandatory.
Australian Prime Minister Scott Morrison - who originally declared yesterday the vaccine would be "mandatory" before revising his language to "encouraged" - added to speculation by suggesting that the "no jab, no play" framework used to compel uptake of childhood immunisation could offer a model for coronavirus vaccination too.
So, in practice, what does that mean? Can those reluctant to receive a new vaccine be forced to accept it? And how would that affect the human rights of those who don't want to receive it?
Who might refuse the vaccine?
Just as some groups have resisted masks for a range of reasons, it is inevitable that some would refuse the jab when, or if, it becomes available.
And vaccine sceptics are already preparing for a fight. A comment on one international website urged "Aussies need your help! They're going to force us to inject DNA modifying vaccine, and they're doing it soon. We don't want our kids injected with poison".
But concerns over a vaccination are not limited to traditional anti-vax groups.
A new US study suggests as many as one in three Americans may refuse a Covid-19 vaccine.
As Russia prepares to roll out its untested Sputnik V vaccine, this statistic appears to reflect genuine unease over the safety of any future vaccine. The urgency of finding a vaccine solution means the potential candidates have progressed far more quickly than usual through the research and trials.
A clue as to how this dilemma could play out took place in the NRL earlier this year when three Gold Coast players were stood down for refusing to have a flu vaccine.
So is it possible for governments to make the vaccine mandatory?
Yes. The Australian Government does have some options for enforcing a mandatory vaccination scheme.
Mirko Bagaric, the Dean of the Swinburne University Law School, says the Australian Government holds the right to compel citizens to have a vaccine even if they don't want it.
"Legally, the Government can impose whatever requirements it wants on its citizens," he says, pointing out the way coronavirus has already reshaped our right to personal liberty, freedom of movement and assembly.
"In Australia we don't have a human rights charter, or anything constitutional or enforceable through other types of legislation."
But Bagaric, who is an expert on punishment, says activating this power would be highly unlikely and "absolutely unprecedented".
The physical nature of a vaccination - piercing the skin - sets it apart from restricting religious, civil or political rights and even from coercing Australians to stay indoors or have their fingerprints taken, he says.
In a legal defence, Bagaric believes it could be argued that enforcing vaccination amounted to torture.
"The human body has always been viewed as inviolable," he says, putting aside for a moment issues of forced sterilisation.
"What a compulsory vaccine constitutes is a violation of what has thus far been assumed to be an almost absolute right. But can the government do it (to enforce vaccination against coronavirus)? Yes, it can."
But should the government do it? For Bagaric, who describes himself as "utilitarian", yes, the government should find ways to enforce a vaccination schedule for coronavirus as it does for standard immunisations.
"I think that norms, rules and laws should be developed on the basis of what's best for net human flourishing," he says.
"If a safe vaccine is available then I think that human flourishing would be enhanced if everyone had that vaccine because the price of living with coronavirus is too high."
What might the consequences be for refusing?
A variation of the "no jab, no play" or the "no jab, no pay" policies have been suggested as one way to withhold some welfare payments for parents whose children are not fully immunised or on schedule to catch up. In some states, it also applies to enrolment in preschools and child care centres.
Morrison says he has a "pretty strong view on vaccines", established during his years as the social services minister responsible for strengthening those "no jab, no play" regulations.
"What is important to understand with any of these vaccines is it does protect you… but it also protects the community," he said. "And, as is the case with any vaccine, there will be some individuals who, for precise medical reasons, can have issues with any vaccine."
When asked how the "no jab, no play" concept could be applied to those refusing a coronavirus vaccine, Morrison wouldn't be drawn.
"I don't think offering jelly beans will be the way to do that as you do with kids," he said. "We'll take it one step at a time, but we'll take those issues as they present and consider what steps are necessary at that time."
But it's not the only option available - there could be something like an "immunity passport", giving those who have been vaccinated more freedoms as restrictions ease.
There would be a "strong public view" that those who refuse a vaccination need "some sort of incentive", Deputy Chief Medical Officer Nick Coatsworth said yesterday.
"Looking at specific things like not being able to go into restaurants, not being able to travel internationally, not being able to catch public transport or more broadly having what in the olden days would have been a yellow fever vaccination certificate, these are clearly policy decisions that will be discussed," he said.
"But there's no current mechanism to enforce that sort of thing at the moment."
Who should be first in line for vaccine?
Stephen Duckett, a health economist at the Grattan Institute with previous experience working in government health policy, says there's a long road ahead before the ethical questions around rolling out a vaccine will be directly confronted.
But when they are, compliance won't be the only dilemma.
Deciding who should be first in line for a new vaccine - and by default, who is first to get the hypothetical "immunity passport" - must also be considered.
Duckett argues healthcare workers should be prioritised, followed by younger people who are at risk, such as those with suppressed immune systems.
These practical considerations hide deeper questions about the kind of society Australia is or wants to be, he says.
"If we have a vaccine, who do we prioritise, what is consistent with Australian values?" Duckett asks. "These are the things I believe it would be good for the society to talk about."
Housing inequalities put some groups at greater risk than others, he says, pointing to Melbourne's social housing towers.
Some of those who lost work as a result of coronavirus are also moving out of independent housing and in with friends.
"This can cause overcrowding and makes social distancing more difficult," he says, adding that such circumstances should make these groups early candidates for vaccination.
Dilemmas like this should also inform how vaccines are distributed, he says.
"We might say perhaps we should prioritise those who society has failed by failing to provide good social housing program in this country."
But, he says, Australia needs to keep its vaccine options open and pursue deals with other vaccine manufacturers as well as Oxford because "we still don't know if this one will fall over at the gate".
-ABC