Welcome to Covid-normal
Australia marked a significant and enviable milestone this week, recording zero cases of community transmission of coronavirus for the first time since its second wave began in Victoria, a Herculean effort with few global precedents.
Professor Allen Cheng, one of the architects of Victoria’s response, says it will be some weeks yet before we can be confident that the virus has been eliminated locally, but we are now among a select few nations grappling with the prospect of post-pandemic life, so-called Covid-normal.
This won’t be a life post-Covid. Experience in countries such as New Zealand has shown that disease leak from returned travellers to endemic regions is going to be a fact of life, even with the most robust quarantine systems. We will have to live with the virus.
What matters is whether we have the systems in place to quash these flare-ups as they arise, and a willingness by the public to continue playing their part in surveillance and response. The result, if we don’t, is plain to see in the northern hemisphere, where the pandemic is accelerating and shows no signs of remit. In the past week alone, some three million cases and 40,000 deaths have been added to the global toll.
“We often talk of the public health paradox,” Cheng, deputy chief health officer of Victoria and one of Australia’s leading experts on epidemiology and infectious disease, told The Saturday Paper.
“Because the output of public health is the prevention of disease, if we do well, we don’t usually know what might have happened if we hadn’t controlled it. But in this case, we have many examples of what has happened in other countries, even those we would usually compare ourselves to, like Europe and the United States.”
Professor Sharon Lewin leads Melbourne’s Doherty Institute, which has been at the forefront of the city’s Covid-19 response. It developed and rolled out Australia’s first Covid-19 test, has sequenced the viral genome of every case in Victoria, is leading the nation’s largest treatment trial, and is collaborating with the University of Queensland on a candidate vaccine.
Lewin, a veteran of the HIV pandemic, says the scale of what Melbourne has achieved, suppressing a 20,000-case surge of community transmission to the point of elimination, is a feat without global parallel outside the pandemic epicentre Wuhan.
She describes the approach as “throwing the kitchen sink at it” – using every conceivable lever, including movement restrictions and other non-pharmaceutical interventions, to crudely suppress case numbers so that the contact tracing system could get up to speed.
Test, trace, isolate is the mantra for outbreak control but, as the second wave hit its stride, Victoria’s system was found wanting. It was outdated, under-resourced and required a significant overhaul, not just in terms of what it did but how it did it.
“We needed a system that was accurate, that was electronic and that was fast,” Lewin says, “and we didn’t have any of that.”
Paper-based systems had to be digitised. Targets needed to be set for testing and notification (24 hours) and contact tracing (72 hours). The scope for tracking had to be expanded from 48-72 hours pre-symptom onset to a full 14 days prior, with contacts of contacts also asked to isolate, effectively ring-fencing potential clusters and shifting focus to identify sources of infection and links to other transmission chains. Decentralisation and stratification of case management was also crucial, Lewin says.
The reformed contact tracing system has been stress tested with outbreaks in Kilmore, Shepparton and, most recently, the northern metro cluster. Lewin says it has performed well, but the real test will be an outbreak in post-lockdown conditions, when the number of contacts won’t be artificially curtailed.
“Our confidence will be reassured when we test the system,” she says.
One of the great unknowns, and something that will need to be teased out with further research, is exactly which elements of Melbourne’s “kitchen sink” approach were most important and would need to be applied swiftly and aggressively in the context of another outbreak.
Professor Mike Toole, who works for the Burnet Institute, one of the groups providing modelling to the Victorian government for its outbreak response, says a new paper currently undergoing peer review for The Lancet shows that mandated mask wearing contributed to a 20 per cent decline in cases. “So masks are essential, the evidence now globally is certain,” he says.
Toole also points to University of Sydney research showing that physical distancing helps drive down cases, but only if adherence is 80 per cent or better. “If it just shifts down to 70 per cent, it’s out of control.”
Toole says masks and distancing are particularly important given the prominence of super-spreader events in Covid-19 transmission, with 70 per cent of cases never infecting another person and 10 per cent infecting the other 90 per cent. In Melbourne’s second wave, the coincidence of Eid and leaks from hotel quarantine saw the seeding of clusters through large indoor family gatherings. For this reason, Toole says restrictions on households should be phased out very carefully.
These measures and robust test-trace-isolate will be key elements of a “Covid-normal” existence, Toole says. He also advocates the national implementation of QR codes for public venues, something that has been more or less uniformly adopted in New South Wales and the ACT but is less widespread in Melbourne. South Korea pioneered the use of QR codes early in its epidemic and estimates that they shave four to six hours off contact tracing time, he says.
Adoption of new antigen-based rapid point-of-care testing will be another important piece of the puzzle, something echoed by Lewin, who describes it as a potential game-changer.
The evolving demographics of Covid-19 will be important in the next phase, adds Toole, with the curve shifting towards younger populations – a group who don’t tend to get as sick and are less likely to take precautions. This not only has implications for schools, which have been demonstrated in countries such as Israel to be important in perpetuating transmission, but also for innovative public health messaging to target teenagers and young adults.
There are many other things we still don’t know about Covid-19, including how long immunity lasts. Recent evidence from Britain is not encouraging on this question, with seroprevalence declining among an Imperial College cohort of 365,000 people from 6 per cent in May to 4.4 per cent in September.
Though vaccines can sometimes confer better immunity than natural infection, Toole says the data gave him serious pause about a Covid-19 vaccine, which he estimates will not be available until this time next year at the absolute earliest. It will also involve mammoth logistical challenges, with the leading candidate a two-dose offering that requires storage at temperatures as low as minus 80 degrees Celsius, a capacity that even most advanced economies don’t have at their widespread disposal. Importantly, Lewin says the current generation of vaccines will prevent disease, not block infection, meaning disease burden will be reduced on the health system but transmission will be able to continue.
“We turned it around in HIV with non-pharmaceutical interventions, good treatments, good testing and community engagement, and we can do all those things for Covid,” she says.
“We don’t yet have a vaccine for HIV and yet we have really had a dramatic impact, so people shouldn’t be disheartened about whether we will or won’t get a vaccine. It will be really important but there will be many other things we can do to get on top of Covid.”
Barring something unforeseen, Lewin believes life in Australia will become some semblance of mask-wearing, distancing, QR-coded, handwashing normal by the end of 2020. The exception is the return of international travel, which she says will not be on the cards for a very long time.
Toole advocates a stepwise expansion of bubbles to low-risk countries, including New Zealand, Pacific island nations such as Vanuatu, Taiwan, Singapore, Hong Kong, Vietnam and, perhaps controversially, China, which he says has essentially eliminated the virus.
A staged return to international trade and travel is a priority for the federal government, and acting chief medical officer Professor Paul Kelly says they are considering a risk-stratified system where people will be able to travel to countries such as New Zealand without needing to quarantine, and may be allowed to self-isolate at home on return from an intermediate-risk destination such as Singapore. Higher-risk locations would still require fully supervised hotel quarantine.
The federal government is also prioritising vaccine planning, including transport and storage logistics, and continues to closely monitor the national medical stockpile, which Kelly describes as a crucial element in Australia’s success compared with other countries where protective equipment rationing and re-use has contributed to outbreaks.
Kelly points to NSW in recent months as a model for so-called Covid-normal, where “we can have open domestic borders and eased restrictions so long as we are able to rapidly respond to outbreaks whenever and wherever they occur”.
“The public does have a role in this, and the reality is we will need to take what we have learnt this year into 2021 and continue to do what works,” he says. “It has been through the collective effort of so many Australians that we have so far been able to avoid the dire consequences the virus has wreaked in some other countries.”
This article was first published in the print edition of The Saturday Paper on Nov 7, 2020 as "Welcome to Covid-normal ".
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