The Doherty Report, released 10 August, underpins the vaccination targets in the federal government’s national reopening plan of 70% and 80% of the population aged over 16. However, since we began this modelling, we have seen large outbreaks in New South Wales and Victoria. These outbreaks prompt questions about how community prevalence affects reopening plans.
how public health and social measures could be applied between 70% and 80%; and differences between the strategy in each state and territory. Doherty modelling update provides the goalposts, but local insights will determine play
Applying “medium” restrictions until 80% coverage is reached, will greatly reduce the likelihood and potential size of an outbreak
But epidemics have momentum and take time to stop.
Differences by state and territory
When Australia reaches 70% and 80% coverage, every state and territory will be in a different position, both in their own coverage and in COVID prevalence. That means every state and territory will have their own path through these transition phases, as allowed for in the National Plan.
With higher case numbers, there will likely be stronger restrictions for longer, while with lower case numbers the contact tracing system is likely to be more effective and able to control outbreaks with lighter restrictions.
Beyond COVID prevalence, there are also differences in the potential for COVID to spread in each state and territory, which we track using the transmission potential (TP) metric. Higher TP means faster spread, and a TP below 1 means cases should decline.
However, for Western Australia the TP would be 1.6, if we assume people behave as they did in March 2021.
Where to from here?
These ongoing projects include helping to define sustainable and effective public health responses; optimising local disease control through vaccines and other measures in at-risk populations and settings; and supporting plans to reconnect Australians with the wider world.
We will factor this and other emerging evidence into ongoing modelling, including regular situational assessments.