More than 48,000 COVID-19 cases would have entered Australia between January and May last year had the federal government not implemented travel bans, according to new research by CSIRO and the Queensland University of Technology (QUT).
The research has shown that Australia successfully lowered the number of imported COVID-19 cases by 88% over that same period, to around 6,000 cases.
The modelling can also be used to forecast the number of potential COVID-19 infections on each flight, based on the number of incoming travellers and the rate of disease in the countries they’re coming from.
The tool could help governments make decisions about travel restrictions and the opening of borders, according to CSIRO research scientist Dr Jess Liebig.
“The model is a flexible framework that can be used to quantify the effects of travel restrictions and to evaluate proposed relaxations,” she said.
“It also enables us to pinpoint the groups of travellers most likely to be carrying the virus, so authorities can more efficiently direct healthcare and biosecurity control strategies.”
When undertaking the research, scientists applied the model to two scenarios: one with open borders and another with the travel restrictions Australia implemented between January and June 2020.
Australia placed a travel ban on China in February 2020, and Iran, South Korea and Italy in March. Later that month, a full travel ban on all foreign nationals was introduced to stop COVID-19 from entering the country. The researchers found these restrictions reduced the number of COVID-19 cases brought into Australia by 88%.
QUT professor Raja Jurdak said the model was the first to quantify the expected number of COVID-19 importations from all countries globally into a particular country.
“The effectiveness of travel bans on individual countries varies widely and depends heavily on the behaviour of returning residents and citizens,” he said.
“If we can better understand and forecast the likely spread of COVID-19 through air travel, we can make more informed decisions about when and how to reopen international borders.”