While Australia’s case numbers are getting worse, increasingly public health commentators are asking whether we should aim for elimination of the virus when we get case numbers back under control, rather than opening up when numbers are low as we did last time. It is helpful to think of this from an insurance perspective. The cost we pay in longer lockdown this time is like an insurance premium against having to lock down again. I think it is worth paying (with the caveat that my own personal cost is smaller than average).

Jealously watching my NZ relatives going about their lives normally (sporting events, funruns, cocktail bars, soon overseas travel), I thought it might be worth a look at how much extra lockdown we might have had to do in Australia to emulate New Zealand and eliminate the virus entirely from the community.

Right now, the Australian view is that suppression not elimination is the right strategy – here is the premier of NSW:

NSW Premier Gladys Berejiklian today warned people in her state to get used to outbreaks, and social-distancing.

“I want to make this point very clear — during a pandemic, when you’re easing restrictions as we have been doing, you’re going to get extra cases and we have to live with that,” she said. “There is no way that New South Wales will have zero cases during a pandemic.

“It’s not going to happen and we shouldn’t expect that we will always going to have cases when we’ve eased restrictions and we have to expect that.”

But many others are questioning that, given how massive the cost is to Victoria of locking down again, and the potential for it to happen in NSW. The article I linked there suggested the cost to the Victorian economy is in the range of $1bn to $2.5bn a week – or $6bn to $15bn for the six week lockdown that is happening there. NSW has a slightly bigger economy than Victoria, so it would be as much again if NSW had to do it.

The graph below shows the pattern of cases in Australia and New Zealand so far.

New Zealand declared the virus eliminated on 8 June. At that point, there were no active cases left in New Zealand, and it had been two weeks since the last new case. The graph below shows the severity of lockdown in Australia and New Zealand over the same time period (complicated in Australia by the different lockdowns in different states):


It is clear that New Zealand’s initial lockdown was more stringent than anything in Australia – New Zealand has a four level approach. Its first four weeks were at level 4, whereas Australia never got beyond level 3. This article sets out the main differences, but basically it was about what stayed open – in New Zealand only essential workers could leave the house to work (you could work if you could work from home) – so no takeaway food, no hardware stores, and no leaving your local government area for any reason.

New Zealand relaxed all restrictions (except for overseas travel) in mid June, when they hadn’t had a new case for two weeks. But they didn’t relax below level 3 (which was our most stringent set of restrictions) until two weeks after the last identified case of community transmission (which was April 29). Timing, rather than level of stringency seems to me to be the crucial difference between the two strategies for Australia and New Zealand. The restrictions across all the states in Australia were largely lifted at similar times. The timing compared with identified cases was quite consistent with New Zealand’s timing for most states, but crucially not NSW and Victoria. The other states had their last identified community transmission more than six weeks ago, and that’s when Australian restrictions were mostly relaxed. That meant that NSW and Victoria lifted their restrictions with community transmission still occurring. And Victoria was not as lucky as NSW in how those last cases turned out, so the outbreak coming from the quarantine breaches wasn’t as visible as it would have been if they were the only cases around.

Based on number of cases dropping, it doesn’t seem that the difference between the initial restrictions in Australia and New Zealand was that great in the level of control. The graph below shows the Doherty Centre’s analysis of R0 (how much the virus was spreading) back in mid April, which shows the lockdown was pretty effective across Australia.  (Here is a more recent paper from them on this topic).

The costs of extra weeks of lockdown are reasonably obvious – both financial and non financial and not small – around $4-10bn a week across Australia depending on who you ask and how you measure it. What are the benefits? Some are more obvious than others:

  • Reduction in the probability of another lockdown (a fairly direct benefit, but not a certain one)
  • Any further outbreaks from quarantine would be more obvious (contrast the WA outbreak from a ship, which was found and eliminated quickly, with the simultaneous Melbourne hotel quarantine outbreak which happened as there were still other cases around)
  • Completely opening the economies within Australia – sporting matches, concerts, theatre, conferences, community events
  • Schools and universities can be more confident about the rest of this year and next year and potentially can open up to international students with a one-off quarantine (with a year 12 student in this house, this is an important one for me)
  • Completely opening the borders in Australia
  • Enabling us to join a bubble with other countries which have locally eliminated the virus (New Zealand and potentially much of the Pacific)
  • And, a reduction in the number of people getting very sick and dying from a very nasty disease (best estimate of the fatality rate is still around 1% of all infections).

Economically, given the massive damage being done right now in Victoria from a second lockdown, it seems to me that elimination is better for the economy and society than rolling suppression. Two extra weeks of harder lockdown this time, compared with another six weeks of hard lockdown in a few months time in either NSW or Victoria seems to me to be a price worth paying.

NSW is a harder call right now, as the contact tracing seems to be working OK, but we won’t know whether it has worked for a couple of weeks when either there are no more cases, or we have an outbreak like Victoria. From my quite risk averse position, I would prefer that we were closing pubs, clubs and casinos in NSW for a couple of weeks. But that wouldn’t cost me very much; for some businesses, that would be enough to destroy them.

I have to close by saying that having watched numerous press conferences from both Daniel Andrews and Gladys Berejiklian over the past few weeks, these decisions are incredibly difficult. They don’t have the luxury of knowing everything or even most things about what is really happening until days or weeks later. No matter what they decide to do there will be pain and suffering for many people. And crucially, when they make decisions that save lives or livelihoods those people who would have benefited from those decisions will never know what might have happened.

Links

One amazing piece of science that has come to the fore in the latest outbreak in Victoria and NSW is genomic testing. While the specific research hasn’t been released, it has been widely reported that the genomic testing done by the Doherty centre has demonstrated that the latest outbreak must have come from the outbreak from quarantine.

The government confirmed this week that genomic sequencing – a form of testing that outlines which specific variety of the virus is spreading in which clusters – shows that much of the latest outbreak has emerged from those original cases in hotel quarantine.

And further research (also not yet released) into the NSW outbreak has now demonstrated that it came from the Melbourne outbreak. This paper from the Doherty centre is an earlier version of this research, which is worth reading to get a sense of how clever the analysis is. Effectively as the virus evolves (so far it seems in ways that don’t change how it makes people sick or its spreading) individual cases can be linked to other cases by looking at exactly which version of the virus they have. Here’s just one of the many examples of how that can be used to improve public health by definitively providing which outbreaks are linked and how quickly they spread.

Third, prior to the implementation of enhanced (stage 3) restrictions in Victoria, we identified a large genomic cluster (the largest in our dataset, comprising 75 cases) associated with several social venues in metropolitan Melbourne. This finding demonstrates the propensity for chains of SARS-CoV-2 transmission throughout urban areas associated with leisure activities and provides additional justification for the unprecedented population-level social restrictions in our setting. Further genomic support for the effectiveness of social restrictions is provided by our phylodynamic analysis, which demonstrates a decrease in Re, after the introduction of stage 3 restrictions (including mandatory quarantine in hotels for overseas returnees), from 1.63 to 0.48. The reduction in Re supports a decrease in disease incidence after the introduction of social restrictions, broadly in keeping with recent epidemiological modelling, suggesting a decrease in Re in Victoria around mid-March 17.

This site allows you to look at this kind of analysis world wide – the link takes you to a particular variant (614) and shows how different countries in the world have had different proportions of that variant over time.

Life Glimpses

I managed to get away down to the South Coast of NSW last week, with friends – we’ve been going down there since we were at university together. It was lovely to see everyone in person, and to support an area that was very badly hit by the bushfires six months ago. Some of us (not me!) even swam in the ocean to celebrate. But while we were there we watched several Victorian press conferences, which made us all acutely aware that (a) it was probably mostly luck that it is Victoria not NSW being locked down right now and (b) our states are so interconnected that NSW must be at high risk of being next.

I feel as if I am trying to get in some social contact before being locked down again. The trouble is that is a tragedy of the commons; if we all do it – then the pandemic will spread and then we will all be locked down again. This graphic below (from the US) illustrates how easily a single family gathering can become an outbreak.

Source: Charlotte Observer

Bit of Beauty

I’m spoilt for choice with pictures today – I’ve been been to some beautiful places since my last post. It’s been hard to choose, but a flower from one of my many walks while I was down at the South Coast is my pick today.

 

7 Comments

  1. I suspect that the opportunity to achieve elimination via lock-down has passed. But if it can be achieved by better physical distancing, greater use of masks, etc, it’s surely worth pursuing for relatively limited short-term pain. (No, I haven’t been to a nightclub for years, either!)

    But elimination brings with it enormous responsibility to manage the borders. Quarantine has to have real teeth (including mandatory tracking?) so that the country remains pure. Those involved in international trade and travel (air-crew, etc) have to be managed. And travel to and from “impure” countries has to be possible, without risking our “purity”. And, finally, the inevitable failures must be jumped on before they become a problem.

    Can we achieve that?

    If not, what does the future hold?

    1. Author

      Richard I agree, it isn’t necessarily easy, but economically having to concentrate just on borders seems simpler to me than the complex dance we are now in. Either way, the quicker we have a widely available vaccine the better!

      1. We may be inching towards significant voluntary take-up of mask wearing, which will reduce the risk of further opening up. At the same time, contact tracing seems to be working — accepting that you’re only as good as your next game and the cost of a single failure can be catastrophic.

        Together with the partial tightening that has happened, that may be enough to get to effective temporary elimination in the community in NSW.

        We have to hope so! History and human nature both suggest that returning to Stage 3 would be far less effective than last time, for equal economic damage. So a second lock-down would be a much more desperate measure than before.

        So the question remains: how do we manage the borders of our bubble(s) until the vaccine arrives? (Images of the US 7th Cavalry, anyone? And, just like waiting for the cavalry, we don’t know how long we have to hold out.) After all, the Crossroads Hotel cluster has been traced to the Victorian outbreak that, itself, comes from the mismanagement of quarantine. It’s a border control issue.

      2. Author

        I was reminded of this comment reading about Hong Kong at the moment – their current outbreak also comes from a quarantine outbreak (not yet as bad as Melbourne). Border control is not easy, and there are lots of anecdotes from many places of people thinking the rules shouldn’t apply to them, but I do think knowing that all cases must be border control issues might help in getting on top of them quicker.

  2. Thanks Jennifer for another reflection. It is very interesting watching from afar how the Australian/NZ approach contrasts with my current experience in France.

    In Paris it feels like we have sort of settled into a “new normal”, aligned to the summer weather and lots of people being outdoors. Cafes and restaurants have increased spaces between tables (although only compared to past practices of Paris – the increased spaces are not huge by any means) and people are planning summer holidays somewhere fairly close within Europe (including some short-haul flying). And masks are very much part of life here indoors or in busy markets, etc.

    But it feels we are a long way away from nightclubs, cinemas reopening or from any size of sporting crowds gathering for some time. Selfishly I was looking forward to seeing Scotland play rugby in Paris in 2021 and not sure even that will be possible….. And we have clearly had a terrible cost in human life so far here in Europe compared to Australia/NZ to get to this stage.

    However, for most people in Paris (clearly those who are not impacted directly by the virus) life “conditions” are currently quite nice and much easier when compared to the attempts at elimination within Victoria. I agree completely with the challenges Richard highlights above to achieve and maintain zero infection. Maybe Paris is an example of the long-term alternative?

    Finally, thanks for the link to the Stringency Index – this is fascinating and I note France as one of the few close to NZ in the severity of the lockdown through March/April. We had clapping for Health workers at 8pm every evening and just annouced a much improved pay deal for these workers. So through it all there is genuine appreciation for those on the front line here.

    1. Author

      Thanks Iain, sounds very similar to my family in Spain – life is a lot better than it was… but NZ has rugby matches (or choirs, which is what I had been hoping for). I think the long term alternative is going to mean masks, and for some reason we seem to have realised that a lot later than almost every other country… probably because we were so close to elimination without aiming for it.

  3. I can only comment on the thing of beauty, it is great. Thank you. Here is chaos, as the politicians fight
    each other and the virus wins for the tome being. Maybe we too will have a complete lockdown, the contact for me then will by phone, Zoom, Skype. As things stand now, everyday has different instructions.
    Anyway, yesterday because it was Quartorze Juillet, I had coffee and croissant, two small ones, in an open air café
    Love and hugs

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