Australia should maintain its COVID-zero strategy until 80 per cent of the population is fully vaccinated, including 95 per cent of people over 70, according to a report from the Grattan Institute.
- Think tank recommends National Cabinet set a vaccine plan to reach 80 per cent target
- Eighty prizes of $1 million could be used as an incentive
- Herd immunity could be difficult to achieve with the infectious Delta variant even if we reach the target
The independent think tank also recommended the government introduce an $80 million lottery with $10 million in prize money for 10 vaccinated winners each week from November, when supply problems have been fixed.
“What that does is give people an incentive to go out and get a vaccine, and reward those who have done the right thing from the perspective of the community,” Grattan chief executive Danielle Wood said.
“We’ve found ourselves doing a lot of things that we never expected to be doing in the past two years. Getting vaccination numbers up is crucially important, and so we do need to be thinking outside the box.”
The think tank has modelled scenarios for how a Delta outbreak could spread at various vaccination rates.
It comes as the federal government considers modelling from the Doherty Institute to help decision makers plot Australia’s way out of the pandemic.
That modelling has been delivered to the government and will now be considered by the National Cabinet, which will set vaccination targets triggers in the nation’s opening up.
‘There are benefits to waiting’
The Grattan Institute modelled case numbers, hospitalisations and deaths under a Delta outbreak at various vaccination rates.
“Our modelling suggests that 80 per cent is the level we need to get to be comfortable that we’ve severed the link between COVID cases and severe health effects,” Ms Wood said.
“Even if the virus is at the more transmissible end, we won’t end up with thousands of people in hospitals, we won’t end up overwhelming our ICU capacity, and in fact COVID at that point looks more like the seasonal flu.”
She said moving away from COVID-zero earlier risks seeding massive outbreaks that will quickly spiral out of control.
“There are risks with going too early … there are plausible scenarios under which you get very strong growth in cases, large numbers of severe cases, and you end up overwhelming hospital system capacity … normally at that point governments end up moving back into lockdowns.
“There are benefits to waiting, we’ve got one shot to do this right.”
Incentives could boost numbers
While there are a significant number of people yet to be vaccinated, regular surveys suggest there aren’t that many firm “anti-vaxxers” in Australia.
Consistently, only around one in 10 Australians have told pollsters that they would never get vaccinated.
The latest polling by Essential Research found most people are either already vaccinated or are keen to get the jab as soon as possible.
The Grattan Institute says the focus should be on convincing the people in the middle, who are likely to get vaccinated but are holding off.
“There is a case for incentives … one thing we’re recommending is a lottery, ‘Vax Lotto’ we’re calling it,” Wood said.
“We also think that we should look at vaccine passports, requiring people to show their proof of vaccination to go into restaurants, large scale events, sporting events.”
Grattan has recommend a weekly national $10 million lottery in Australia with 10 $1 million prizes each week, starting with the first draw on Melbourne Cup – and then each week until the Tuesday before Christmas.
It has suggested every vaccinated Australian could be in the draw each week (as well as people with a medical exemption to vaccination) and those with one jab would have one chance each week, with those who were fully vaccinated doubling their chances.
How long would it take?
Ms Wood said with a concerted effort, an 80 per cent vaccination rate is “ambitious, but it is achievable”.
“Our numbers suggest you could get to 80 per cent by the end of the year if a vaccine becomes available for children under 12 and we distribute that in schools,” she said.
“If we don’t get approval in the next few months for that type of vaccine, it will take longer … we think certainly by the end of March 2022 is achievable.”
Australia’s regulator has approved the Pfizer vaccine for children over 12, and clinical trials are underway in younger age groups.
Herd immunity difficult to achieve: researchers
Separate research led by James Cook University infectious diseases physicians and mathematicians suggests we would need to vaccinate as much as 85 per cent of the population to achieve herd immunity.
The preprint paper, yet to be peer-reviewed, suggests that number will be difficult to reach without also vaccinating children under 15.
Infectious disease modeller Emma McBryde said if the virus becomes even more infectious than it is now, herd immunity may not be possible through vaccination alone.
The precise vaccination rate required to reach herd immunity depends on both the variant you’re dealing with, and the effectiveness of vaccines.
“With the Delta strain, herd immunity is much harder to reach,” she said.
“It’s much more infectious … instead of needing to vaccinate fully 60 per cent of the population, it has gone up to 80-85 per cent, which means we probably will need to vaccinate teenagers in order to achieve herd immunity.”
But even if that rate isn’t achieved, Professor McBryde says we should still strive to get as close as possible.
“We will still get good measures of herd protection without getting herd immunity.”
Every single dose helps
The Grattan Institute estimated a similar threshold for herd immunity as the James Cook University team.
But even if we don’t reach herd immunity, we still benefit, as every single dose deprives the virus of opportunities to infect and cuts the transmission rate.
Under Delta, some estimates have found that each infected person will pass the virus on to five or more others in an unvaccinated population — or in other words, with no vaccinations it has a reproduction number, or Reff, of five.
Every vaccinated person nudges that transmission rate down. When we get to the point where the Reff is one through vaccinations and natural immunity alone, we reach herd immunity.
If you open up while close to herd immunity, but not quite there, you’re left with a low enough rate of infection that restrictions needed to bring an outbreak under control would be less intense.
Mask-wearing might do it, for example, rather than the need for a serious lockdown.
The James Cook University researchers also examined questions about who should be prioritised in the vaccination rollout.
“The best strategy from the start is to vaccinate the vulnerable, older groups first,” Professor McBryde said.
“From here, now that the most vulnerable and the older groups have had every opportunity to get vaccinated, the next strategy is to look at the people doing most of the transmitting.
“That’s generally the younger age groups … and of course the particular occupations where people are in the public domain the whole time, such as the … people working at supermarkets and pubs and those sorts of things.”
When do lockdowns end?
What, precisely, Australia looks like in the early stages of opening up is yet to be determined by the National Cabinet.
Their proposal is to first ease domestic restrictions on vaccinated residents, only use lockdowns in the most extreme cases, and start to increase visitor limits, especially for vaccinated travellers.
Subsequent stages would see vaccinated Australians exempted from all domestic restrictions and lift restrictions on outbound travel for citizens.
Until then, Australia sticks to striving for zero COVID, as difficult as that has proven to be under Delta.
“We say that once you get to 80 per cent, you should really have no more intrusive public health restrictions,” Ms Wood said.
“No more lockdowns, no more capacity limits at venues, and that’s the point as well that you would start sequentially opening up borders.”