This is not good Epidemiology

6 weeks from the WHO declaring a worldwide pandemic and with New Zealand announcing they are stepping down their restrictions one level (we’ll get to what that means later), there has been more discussion about easing restrictions. In particular, people are beginning to speculate on timelines for this easing. There seems to be some incongruence with events being canceled through August, discussion of courses going online in September, yet also talk about things ‘getting back to normal’ as early as June.

So which is it? How do we know?

I’m going to open by saying I am not an epidemiologist, I have no training in pandemics or virology, and everything I share is simply my speculation based on data I’m looking at. Take it entirely with a grain of salt, this is not good epidemiology. This is not the opinion of an expert. I welcome being proven wrong now or later. However, I wanted to provide some context regarding my current thoughts on the timing around easing restrictions.

I speculate that the timing around easing restrictions will be long, and the easing will be slow.

I don’t think I bring pessimism to this speculation, rather there are a couple of graphs that make me feel that we have quite a ways to go here. The first one is:

Look at where Canada is and notice we are still on an upward trajectory on a logarithmic scale. Now look at New Zealand at the bottom. Look at the post-peak trajectories of all nations and apply any one of these angles to where Canada is now. If our new cases were to start declining immediately, today, even applying any single one of those trajectories puts us at around 60 days to be at where New Zealand is at today. And that’s assuming the best case scenario that things get better for us from today forward. So let’s say end of June for example. I scribbled a random line on the chart to show what I mean:

A correct angle on the random line probably puts us well into July.

Here’s another helpful graph:

Short of a miraculous cure, although we are tipping the line, there’s a heck of a way to go for it to get to the bottom of the chart.

Essentially, from where we are today we’re talking at least a couple of months before COVID-19 deaths become minimal, and this is with all things remaining equal (and assuming our trajectory follows others). [This is part of why the U.S. approach of late distancing is going to be so much of a problem, the length of their curve stretches beyond the end of any graph, the higher the initial peak the longer the recovery. They are not going to be an ideal neighbour to say the least.]

So let’s talk about where New Zealand is at. Having achieved near zero new cases they have reduced their emergency level from 4 to 3 (https://covid19.govt.nz/latest-updates/new-zealand-be-at-alert-level-3-from-tuesday-28-april/). What does this mean? Essentially a couple of things: your family can expand it’s bubble as long as you keep your bubbles mutually exclusive. So, you can start hanging out with grandparents or a neighbour as long as the grandparents and neighbour have only started hanging out with you and have not added their uncle and co-workers into their own bubble. Secondly, some businesses can re-open with no contact in place. Importantly, this is not a return to normal, it’s a slight easing on restrictions.

Why the cautious approach in New Zealand? Look at the China curve: when you ease restrictions you have secondary outbreaks. Until we can test the whole population (for immunity or infection) and perhaps have N95’s available for all, or until a vaccine is available, it’s about minimizing infection versus hoping it will fully go away. We have no indication yet that supply chains are in place for mass testing and mass PPE any time soon.

So, let’s go back to my initial comment that Canada is at bare minimum two months out from minimal new cases (based on holding up a pencil against someone else’s graph, as a reminder, not quality science). Yes, we could begin easing restrictions before the cases get this low, we could also do this regionally/locally. The challenge is, the earlier you ease, the bigger that subsequent wave. While people may begin to press the government to lift early, how many human lives are worth opening a few more stores or expanding our bubbles by 5 more people? Who would want to be the Premier or Prime Minister who decides to shift from minimal deaths to a moderate level of deaths?

So, back to my personal position that this is going to last a while longer. I suspect that even if we do have a best case scenario in decreasing infections it will still be a while before we’re low enough to be comfortable in increasing risk. And, once we start increasing the risk, I suspect it will be slowly and cautiously. This is why I think we’re still talking many more months here.

Conclusion:

Why, as a researcher and scientist, would I dare speculate in a field outside of my expertise? While positivity and enthusiasm are good, I worry that being over ambitious about a return to normal may push governments to making rash decisions. With a child who is high risk and two grandparents in long-term care, this risk is very real to me and my family.

So, stay positive, stay happy, but stay patient. Allow our governments to make decisions about the pandemic based on the best expertise of our medical professionals and respect those decisions. Stay physically distanced but socially connected. We all miss normal life but as I saw it stated on Twitter, “It’s better to not have your hair cut than to have it cut by a mortician.” Stay strong.

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