To lockdown or not to lockdown?

Australia does not have a national strategy to deal with hotel quarantine breaches and consequent outbreaks. 

Queensland Premier Annastacia Palaszczuk tends to impose snap lockdowns as soon as a positive case is identified in the community, then calls for the number of international arrivals to be “cut right down”.

Victoria has gone repeatedly through extended lockdowns, while NSW Premier Gladys Bereijiklian is so reluctant to impose lockdowns that when she must enforce them, she calls them “stay-at-home orders”. She says NSW contact tracers are “the best in the world” in keeping up with the virus. Until they don’t.

When the Sydney limo driver who carried international aircrews tested positive with the new highly contagious Delta variant of SARS-CoV2, concerns immediately arose. 

When positive COVID-19 cases began to appear across Sydney in the following days, a heated debate ensued among experts. Some called for a go-fast, go-hard approach. Others were more confident a lockdown could be avoided.

“Every outbreak is different,” says Professor Catherine Bennett, chair in epidemiology at Deakin University. “But we’ve got the data, particularly from the last set of outbreaks in Melbourne, from which we could map out what-if scenarios.”

What if that person was more infectious? What if it was Kappa rather than Delta? Could we have managed the outbreak without lockdown? Which elements of the lockdown work and which don’t make much of a difference?

“[States have] got really rich and good data now,” says Bennett. “We need them to be doing that work and report on that work so that we can have confidence that what we are asking [the community] to do is informed by exactly what we know about how these variants move through our community, and how our community moves itself.”

Bennett says that 18 months into the pandemic, that data could be extremely useful in evaluating the states’ outbreak responses and identifying which restrictions drive cases back to zero. “We just keep applying this whole package of serious restrictions with punishment linked to it, without a formal evaluation,” she says.

Professor Mary-Louise McLaws, an epidemiologist at the University of New South Wales and advisor to the World Health Organization, agrees. “There’s very little transparency of any data in Australia,” she says.

Imposing restrictions, she says, is not just a matter of mathematical modelling or looking at case numbers. It’s an outbreak management process that is based on the evidence of the gathered data.

“We need to evaluate lockdowns not with theoretical modelling, but with the actual data,” says Bennett. “Maybe we can just put those bits that work in place, and take some of the other bits that cause additional anxiety but don’t add anything epidemiologically out.”

Read more:

• Cosmos Briefing: Modelling
• Delta is keeping Australia on alert
• Can I shed a virus after I get a vaccine?