April, May, and beyond, Part 1: What’s coming next?
I was speaking to someone recently about the likely timeline of the pandemic. She asked me, in a somewhat plaintive tone, “Are we going to be teleworking for 12 months?” My response, “Probably...maybe longer,” was not easy for her to digest.
She and I both recognize the tremendous privilege she has with having a job that can accommodate teleworking rather than being forced to interact with other humans at work or not having a job at all. But I think this exchange shows where a lot of people are right now -- adjusting to the current circumstances and not yet able to grasp the magnitude of what’s happening. Focusing on today is appropriate and necessary for most people right now. If that’s where you are, that is completely okay and you might want to skip reading this post.
For those who are moving past that phase, who are ready to hear what’s coming next, let’s talk about it.
What does the future look like?
The short term (today through early June)
Some areas are starting to see benefits from social distancing (e.g., Washington and California). For areas that start social distancing later, they too will benefit eventually but have a hard road ahead of them until then. The impact of these interventions on the number of new cases won’t be seen for 2-3 weeks and the number of new deaths won’t start to decline until 3-6 weeks after social distancing is implemented. Daily numbers of new cases and new deaths will continue to increase in many areas -- I don’t just mean there will be new cases and new deaths each day, I mean that the daily number of new cases and deaths will keep going up. For example, 2 people died in Alabama on March 30th, 7 more people died on March 31st, and 13 more people died on April 1st. That trend will continue. At peak, Alabama will probably have several hundred deaths per day from COVID-19.
The number of new cases and new deaths are only indirect measures of the impact of COVID-19 on our healthcare systems. Even when the number of new cases start to decline in mid-April/May, it will still be months before hospitals are no longer overloaded and our healthcare system can go back to something resembling a normal routine. (This doesn’t take into account the time needed for our healthcare workers to recover from the physical and psychological strain of the crisis.)
How do we know this? Many scientists have created mathematical models that use what we currently know to predict future trends. They’re not perfect but they give us a general idea of what to expect and help guide future decision making. The Institute for Health Metrics and Evaluation (IHME) has useful models for the U.S. and individual states. Using their tools, you can see when the pandemic is likely to peak in your state. Their model is fairly simple, which is why there’s such wide uncertainty around the estimates (the shaded areas around the lines), but it’s still helpful. For people who are really interested in the science behind modeling, the folks at FiveThirtyEight wrote excellent articles on why creating an accurate COVID-19 model is so challenging and why models vary so much, and Dr. Zeynep Tufekci explains why you need to be thoughtful about interpreting models (because if you act on them, the outcomes change.)
In the short term, social distancing orders in your area, including school closures, will probably extend until after well past the local peaks in April and May. For most states, expect that schools will stay closed through the start of summer break. Summer camps will likely also be impacted. Healthcare will probably continue to be significantly disrupted until late June or July. These timelines may extend for areas that have been slower to implement social distancing.
The longer term (late summer and after)
Reality check: this is probably just the first wave of coronavirus in the U.S. When the number of new cases and deaths drop in May and June, that is a short-term reprieve, not an end to the pandemic. For many people this is both hard to hear emotionally and hard to really comprehend intellectually, but this is the reality.
As many experts have already said, there are only two ways out of this in the long run -- enough people get immune because they were infected with COVID-19 and recover or enough people get immune because they were vaccinated. This is what scientists mean by herd immunity. The first strategy involves lots of people dying and the second involves lots of waiting while we implement interventions that no one likes (e.g., school closures and social distancing) until we get a vaccine.
The big challenge ahead is that when the number of new cases and deaths start to drop over the next two months, there will be tremendous pressure on elected officials and health departments to let people get back to normal. If that happens, we will then see a resurgence of COVID-19 and the cycle will start all over again. This approach, relaxing social distancing as soon as we see improvement and reinstating it when cases start climbing, would lead to overlapping see-saws of lots of infections and lots of social distancing until we get to herd immunity in some fashion.
Aside from the chaos, deaths, and economic impacts associated with that approach, there are other problems. The percentage of the population that needs to be immune for herd immunity to work is disease specific. For measles, it needs to be higher than 92%. Thankfully, it’s probably lower for COVID-19 -- experts have estimated that we need 50-90% of people to be immune for herd immunity to work in most areas (Kwok et al, interviews with multiple experts). But here’s the problem. When we are past the first wave of infections in early June, the IHME model estimates that less than 5% of the U.S. population will have been infected with COVID-19 so less than 5% be immune to the virus. This is consistent with the White House Coronavirus Task Force projections as well. It would probably take at least 5, and probably many more, waves of COVID-19 infections to get to herd immunity this way. This approach, many cycles of unplanned reactive see-sawing between deaths alternating with strict social distancing, will probably create more social and economic damage in the long run.
There are alternatives that would avoid some of the chaos and still decrease the impact of COVID-19 on our health, society, and economy, but there is no way to avoid those impacts entirely. We missed the boat on that possibility in the U.S. back in January and February. We continue to have to make hard choices. Tomorrow I’ll talk about some of our options and their pros and cons.