Half of Australia’s population of 25 million is now under lockdown. The arrival of the highly infectious Delta variant of COVID-19 has challenged the wisdom of the country’s yearlong zero tolerance strategy. Strict border closures and mandatory quarantines have kept the numbers of COVID-19 cases and deaths relatively low, but it may have also made Australians complacent about getting vaccinated and reluctant to learn how to live with the virus. Marco Werman speaks with Catherine Bennett, chair of epidemiology at Deakin University in Australia.