Hopefully Victoria will have successfully dealt with its second wave by then, but the situation could remain precarious. Cases will continue to pop up elsewhere. Premiers will probably stay inward-looking. The political blame game, now in full swing, won't have abated.

As the flowering wattle and blossoms tell us spring is almost here, the summer that follows will be anything but relaxed and comfortable.

Scott Morrison at the moment is deeply frustrated - by the bleakness, by those state and territory leaders in their fortified fiefdoms, by the criticism he's copping over his government's poor performance in protecting the elderly in residential aged care.

When he finds himself on the back foot, Morrison's response is to look for a way to jump onto the front one. This week he used as his springboard the announcement that Australia has signed a letter of intent with the company AstraZeneca for a supply of Oxford University's COVID-19 vaccine, if its trials are successful.

"Today is a day of hope - and Australia needs hope, the world needs hope," he declared, as he undertook a publicity blitz on Wednesday.

And hope is what we're talking about here. Not certainty. The world doesn't yet have a vaccine, from anywhere. Maximum effort is being made to produce one, and there are many trials and encouraging signs - although the pessimists note there has never been a vaccine for this type of virus. Even assuming a vaccine arrives, it might be with limitations. Some people who have flu injections still get the flu.

And if it comes, that could be a considerable while away. Morrison said if the trials were successful "we would hope that this would be made available early next year - if it can be done sooner than that, great". But experts often have a longer timetable - mid-year or later.

If the vaccine materialises, the immediate issue will be to triage who gets it first, but a more fundamental one will be to ensure enough people get it.

Morrison says a 95 per cent take-up would be needed for proper community protection (this figure would be lower with a totally effective vaccine). He made it clear he thought that, medical exceptions aside, everyone should have to be jabbed.

"I would expect it to be as mandatory as you can possibly make [it]," he said. As social services minister he brought in the "no jab, no pay" policy, which denies certain government payments to those whose children aren't immunised.

This is sensitive territory. Not only would the vaccine have the anti-vaxxers out in force, but quite a few people would worry about its newness, or have other fears, however unjustified. Remember the controversy about the pretty harmless COVIDSafe app.

Unless it was mandatory, the take-up could be inadequate, with some young people, for example, not bothering - just as a portion of the population persists in not having flu shots.

Pauline Hanson was predictable: "I'm angry. You have no right to say I have to have this vaccination, because I won't be having it," she said.

Morrison quickly saw the suggestion of the vaccine being mandatory threatened to play badly (even though we have been living for months with massive degrees of compulsion, and Victoria currently is as close as Australia will ever get to a police state).

By late Wednesday he was becoming exasperated, saying on 2GB: "Can I be really clear to everyone? ... It's not going to be compulsory to have the vaccine. Okay?

"There are no compulsory vaccines in Australia. ... I mean, we can't hold someone down and make them take it."

The Melbourne Institute's Taking the Pulse of the Nation survey published on Thursday highlights how acceptance of COVID-19 measures varies, including among particular cohorts of the population, and points to the importance of building consensus around them.

The August 3 to August 8 wave of the regular survey asked people: "Which mandatory government regulations would you be willing to accept to allow a return to normal activities?" It didn't ask about vaccination, but its findings are relevant for that debate.

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In the survey, all groups, regardless of age, gender, income, education or politics, were willing to wear masks, self-quarantine if exposed and face capacity restrictions on public transport.

But there was much less acceptance of routine weekly testing, closure of non-essential businesses and contact tracing with mobile phone data. Moreover, younger people (under 35) were notably less willing than older people to accept measures such as weekly testing and phone tracing.

Analysing the results, Marco Castillo and Ragan Petrie, from the institute, conclude that if the virus persists, "solutions that balance public safety and the return to normal economic activity may be needed".

"Measures like routine weekly testing and use of mobile phone data for contact tracing can help transition out of the current restrictions and help open the economy," they say.

But such measures throw up the problem of divided opinion and the challenge of consensus-building.

If we get a vaccine, strong support for it can be expected. But its effectiveness could be undermined by activist opponents, the worried and the "I don't need it" brigade. Even combined, they might add to only a small proportion. But given the virus's virulence, they could reduce its community effectiveness.

How to maximise coverage will be a priority for when (or if) there actually is a vaccine, but the government needs to start working hard well beforehand on creating overwhelming backing, allaying fears and countering critics and contrarians.