New Omicron modelling shows WA should cope when borders reopen

New modelling on the Omicron variant of COVID by The University of Western Australia suggests WA should be able to cope with an outbreak if the borders reopened in late February.

Infectious disease modeller and lead researcher Professor George Milne, from UWA’s Department of Computer Science and Software Engineering, found the peak would come about 55 days after the border reopened and last a couple of weeks.

The new modelling, which has not yet been peer-reviewed, suggests a peak of about 430 people in hospital two months after borders reopen, with approximately 10 per cent of those, or about 43, in intensive care.

“What’s interesting is that we’re able test our model-based predictions against what’s been happening in Victoria, Queensland and South Australia, and were able to replicate their hospitalisation rates very accurately.”

Professor George Milne

Estimates of ICU surge capacity detailed in a recent paper in the Medical Journal of Australia by Associate Professor Ed Litton, from UWA’s Medical School, and ICU colleagues Australia-wide suggest that WA has 52 extra ICU beds but only about half of these would be fully staffed.

“There’s a shortfall between our estimated ICU bed demand and fully-staffed excess capacity, but my thinking here is given the short duration of a peak demand it’s possible that the WA health system can cope with the facilities and staff resources that we’ve got,” Professor Milne said.

“Omicron infections and therefore hospitalisation numbers are known to grow rapidly and then decrease rapidly, with peak hospital demand of short duration. Data from overseas and from our modelling indicate this.”

The modelling assumed mask-wearing and some level of social distancing compliance in the population.

“It appears that people are naturally adopting some form of social distancing in response to Omicron in their community – Google mobility data that tracks phone locations is showing a lot fewer people in the CBD district in Melbourne and Adelaide – that behaviour will probably happen here as well,” he said.

Professor Milne believes that delaying reopening much past the original date of February 5 will not make much difference.

“The benefit of further booster shots will be at risk of being offset by waning immunity among those who are already vaccinated with a third dose,” he said.

“There will come a point where it will get harder to get higher levels of immunity in the population without ongoing COVID-19 infections occurring.”

/University Release. View in full here.