Health modelling behind Queensland’s reopening plan reveals severe pressure on state’s hospitals

Queensland will in a worst-case scenario experience 1200 daily Covid cases and 400 ICU patients once borders reopen, but it’s the young and especially the elderly who will fare worse, health modelling reveals.

The young and old will shoulder the majority of Covid infections once Queensland’s borders open up, but the elderly will fare worse, according to modelling relied on for the state’s reopening plan.

The newly-released data shows assumptions the government has relied on to draw up its reopening plan and how the virus will spread, with a worst-case scenario of 1200 daily cases and 400 in ICU.

It finds there will be higher rates of death in the elderly, and that young children, although unable to be vaccinated, will be less likely to be symptomatic or suffer severe illness.

Commissioned by Queensland Health, the work from the QIMR Berghofer Medical Research Institute and based on Burnet Institute modelling, found hospital resources “may come under severe pressure but not catastrophically so” before control measures can be enacted.

“Our projections suggest the health system would be strained but not to breaking point,” it says.

Queensland’s health system will face severe pressure once the borders reopen. Picture: Annette Dew

“The precise location of an outbreak may have a large effect on health system impacts, due to Queensland’s heavily decentralised geography – an outbreak in regional Queensland may hit capacity limits far sooner than in Brisbane,” it reads.

“The young and old age groups carry most of the infections, but the severe health outcomes load heavily on the old.

“Waning of vaccine-derived immunity may mean the above is optimistic and boosters and/or vaccinating more of the population may be needed.

“Extending the rollout to younger children (eg aged 5-11) may help reduce case numbers, though there are not yet vaccines approved for those ages.”

Number of people in ICU based on 70 per cent vaccinated (red), 80 per cent vaccinated (yellow), 85 per cent vaccinated (green) and 90 per cent (blue).

The work assumes people will continue to be tested, contact traced, that positive cases are isolated and their contacts go into quarantine.

Reopening in absence of these “TTIQ” measures would be likely to trigger an outbreak, it said.

But the modelling concedes people may be less likely to continue to be tested and may be unwilling to isolate once there are high levels of vaccination.

“Our results do not include reduced compliance with TTIQ measures over time,” the report reads.

Daily infections for four reopening scenarios based on 70 per cent vaccinated (red), 80 per cent vaccinated (yellow), 85 per cent vaccinated (green) and 90 per cent vaccinated (blue).

“Our assumed rate of testing may be low for a large outbreak, though high vaccination rates may also dramatically reduce the population’s willingness to test and isolate.

“Likewise vaccinated people may be less compliant with QR sign in or responding to public notices of exposure sites.”

The report says results may also be optimistic if hesitancy prevents Queensland reaching 92 per cent total double coverage in the over 16 age group.

Daily new infections with (red) and without (black) waning of vaccine-derived immunity.

The modelling would be impacted if there were already significant outbreaks in Queensland by the reopening date, slated for December 17.

The modelling considered four potential border reopening points triggered when 70 per cent, 80 per cent, 85 per cent or 90 per cent of the population were double vaccinated.

It simulates outbreaks over the period of October 31 to August 28 and assumes random new infections in Queensland residents at an average rate of 10 per day.

Originally published as Health modelling behind Queensland’s reopening plan reveals severe pressure on state’s hospitals