The highly infectious delta coronavirus variant has broken through Australia鈥檚 covid-19 defences and sparked the worst outbreak in Sydney since the beginning of the pandemic.
Until this week, Australia had made it through 2021 without a single death from locally acquired covid-19. Community cases were mostly kept at zero by banning international visitors and quarantining all Australians returning from overseas, and life was largely back to normal in the country.
But a new outbreak, which began in June with the infection of a Sydney limousine driver who was transporting international aircrew, is proving difficult to control. The greater Sydney area has been in lockdown since 26 June 鈥� people can only leave home for essential reasons like buying food 鈥� but the number of cases has still climbed past 800. This makes it the worst outbreak since Sydney鈥檚 first covid-19 wave in early 2020, which infected about 2000 people.
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Two people have died 鈥� a woman in her nineties on 10 July, followed by a man in his seventies.
Cases are also starting to spread beyond Sydney to regional New South Wales and the neighbouring state of Victoria, which has also gone into lockdown.
Authorities are struggling to identify and isolate all infected individuals before they pass on the virus because they are infected with the highly contagious delta variant, says at Deakin University in Melbourne.
Examination of from a Sydney shopping centre suggested that one person caught it just by walking past an infected individual 鈥� neither of whom were wearing masks. 鈥淭hat鈥檚 all it takes 鈥� just drawing in air that someone鈥檚 recently exhaled,鈥� says Bennett.
Only 10 per cent of Australians are fully vaccinated against covid-19 鈥� the lowest rate of all member countries of the Organisation for Economic Co-operation and Development, which are generally high-income nations. This low vaccination rate is also making the virus harder to control, says Bennett.
Reasons for this lag include vaccine supply issues, safety concerns and a poorly coordinated roll-out, says at the University of Sydney.
Australia initially planned to rely mostly on the Oxford/AstraZeneca vaccine, but then decided to restrict its use to people over 50, then over 60, after it was linked to very rare cases of a blood clotting disorder. The government has been slow to procure other vaccines for everyone else and has left the public confused about when and how they can get vaccinated, says Leask.
The delta variant has also jumped into the community from hotels in Melbourne and Brisbane where infected people were being quarantined, causing small outbreaks that had to be stamped out with snap lockdowns.
鈥淸The delta variant] is like a finer sand that can find the cracks in these systems more easily,鈥� says Bennett. 鈥淚t鈥檚 just telling us we can鈥檛 hold the borders. The next variant could have that extra edge again, so we really have to step up vaccination.鈥� Australia has minimal community immunity due to low covid-19 case numbers, leaving it vulnerable, she says.
Bennett believes Sydney鈥檚 lockdown measures will eventually contain the virus, but it is difficult to know how long it will take. 鈥淚 do think, though, that it can still turn around reasonably quickly,鈥� she says.
Australia will probably have to keep its border shut and continue relying on lockdowns to control the virus until at least 60 per cent of the population is fully vaccinated, says Leask. 鈥淏ut there鈥檚 no magic number 鈥� it depends on how well you want to control the virus and things like the capacity of vaccines to protect against new variants,鈥� she says.
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