At the beginning of June about 30 percent of Australians said they are unlikely to get vaccinated at the moment. That figure probably went up when the national expert panel on vaccination raised concerns about the rate of vaccination related clotting for 50 to 60 year olds using the AstraZeneca vaccine.

So what are the chances of reaching the 70 to 90 percent vaccination rate that we are likely to need if we are to have a new normal without widespread restrictions and lockdowns?

Looking at childhood immunisation rates, anti vaxxers are probably less than 10 percent of the population. Conspiracy theories, false information and commercial exploitation drive this group. Short of draconian limitations of free speech and an utterly devastating local infection rate to motivate them, it is unlikely much can be done to convince anti vaxxers to consider having a COVID vaccination.

However imperfectly, it looks as though about a quarter of the population is trying to make decisions based on whether the benefits of vaccination outweigh the risks. This involves making assessments on the likelihood of community spread of COVID, and individual health and social circumstances.

You’re probably less likely to get vaccinated if you think there is little risk of catching COVID at the moment; you’re younger and in good health; you can’t make the time to get vaccinated, you’re less affluent, and you’re not confident about the safety of vaccines.

Paradoxically, the benefits of COVID vaccination are clear when there is widespread community transmission as is the case in Europe, the UK and the US. Then vaccination means you are much less likely to get seriously ill and very unlikely to die – a powerful personal incentive. As well, increasingly, it also looks as though vaccination can dramatically reduce the likelihood of community transmission – a good public incentive.

On average, across all age groups, about 6 people in a 1000 who catch COVID die. By way of example, In the UK by the middle of June 127,000 people had died from COVID deaths since the start of the pandemic – about 1 in 440 of the population. It is likely that about a quarter of the UK population was infected by mid June. The risk of dying therefore continues to increase as more of the population becomes infected.

The evidence is that the chance of dying from COVID reduces by 80 percent for those who are fully vaccinated with AstraZeneca and more like 90 percent for Pfizer. But there is a risk of dying from an AstraZeneca vaccination, although it is low – about 1 in a million. So with a much higher risk of death from COVID than vaccination, the benefits of AstraZeneca in countries like the UK are obvious.

But Australia’s success in suppressing COVID changes the equation. Right at the moment in the middle of June, there is very little risk of catching COVID, getting seriously ill or dying.

For Australia and other countries that have effectively eliminated COVID, the safer Pfizer vaccine looks like the better alternative, even though the risks of AstraZeneca are extremely low.

But right now in June, Australia has plenty of AstraZeneca and only limited supplies of Pfizer until September and October when plenty of Pfizer is predicted to be available.

With little threat from COVID many hesitant Australians are now extraordinarily risk averse and are willing to wait until later in the year for Pfizer rather than take the tiny risk with AstraZeneca. Of course that equation shifts quickly when COVID emerges as happened in parts of Melbourne in late May.

The risk and benefit calculation changes further depending on your age and health. The risk of dying goes up steadily for each decade in age. For those over 80 the chances of dying if they catch COVID goes up more than 10 times to around 80 per 1000 people.

Not surprisingly, those at greater risk of dying if COVID does spread are more willing to take the chance on AstraZeneca, especially since it looks like there is less risk of clotting for older people.

By contrast healthy younger people are extremely unlikely to die from COVID. When there is very little community spread, it makes little sense for them not to wait until the Pfizer vaccine is available.

Where you live makes a difference too. it is understandable that those in far flung country regions, a long way from international airports and potential quarantine breakouts see no great urgency and might want to wait for Pfizer as well.

On the other hand, living in big cities, particularly Melbourne where there have been a number of quarantine breakouts probably changes the risk-benefit equation in people’s minds. Understandably, those who have family and work demands and less time to get across the detail might also decide to wait as well.

Overall, the picture is complicated and worse it keeps changing as new data becomes available. Setting aside anti vaxxers, it is not surprising there is hesitancy in the community. But if we want to lift restrictions and lockdowns permanently we will need to overcome hesitancy and reach the 70 to 90 percent vaccination rates required to stop widespread community transmission.

While the supply of Pfizer is limited and COVID is not much of a threat many will wait . The real challenge will come in October when Pfizer is much more available.