Delaying the COVID-19 epidemic in Australia: Evaluating the effectiveness of international travel bans

Adeshina Israel Adekunle; Michael Meehan; Diana Rojaz Alvarez; James Trauer; Emma McBryde

After an initial period of inactivity, many governments have now moved to impose international travel restrictions to prevent any further importation of COVID-19 cases. However, given that the virus is now a global pandemic and has reached most countries it is reasonable to question the impact of ongoing travel restrictions. In this short communication we have used international flight data and models of disease transmission to predict the national epidemic trajectory had travel bans not been put in place. Our results show that the travel ban on individuals arriving from China successfully delayed the onset of widespread transmission in Australia by four weeks. We also showed that travel bans from Hubei Province alone would have been much less effective, as the virus had already spread to many other provinces by the time the bans were enforced. Similarly, until now travel bans for South Korea and Iran (imposed on February 9 and March 5 respectively) were also shown to have negligible impact. However, as the number of cases in these countries continues to rise we expect these restrictions to become increasingly effective. Universal international travel bans coming into force now appear to be the only rational response, however, we need to consider how long they can and should last.