Julie Swann: Do you mean officially? I mean, a pandemic is when a disease is spreading across multiple countries globally, where resources are needed to avoid bad outcomes. So, we may never get rid of it in that sense.

There are a couple of important signals. In January 2020, the World Health Organization made a formal declaration of a “public health emergency of international concern.” The declaration is regularly reviewed and can be ended. This tells countries they need to invest resources to reduce the spread of a disease that is spreading internationally. So one signal would be if the WHO ended that declaration. However, I do not expect this for a while given the current spread worldwide and ongoing risk.

I am also watching for a declaration by the US Secretary of Health and Human Services that the formal Public Health Emergency has ended. This has been extended multiple times and currently is in effect until at least mid-April. This type of official declaration also has implications for telehealth, waivers, and flexibility for a number of stakeholders in the overall health system. If you define a pandemic as a disease that is prevalent across the entire world, with significant drains on health systems, then it may be a long time before we are truly past that stage, although the experience in some local areas may be different.

Matt Koci: There’s the technical definition and then there’s what we’re all experiencing. Don’t get me wrong, when we get to a point where the WHO says COVID isn’t a major issue in some parts of the world, that will be a good sign and one of the first steps towards everyone being able to put the worst part of COVID-19 behind us. However, we need to be careful and not over-interpret that news as the end of the struggle.

As Julie said, pandemic means an epidemic is happening everywhere on Earth. At some point in the future (hopefully sooner rather than later) large regions of a continent will no longer have COVID epidemic conditions, which will mean COVID doesn’t meet the pandemic definition. But that doesn’t mean things are better everywhere. A lot of people will still have a long way to go.

So the practical question, the selfish question, is: how will we know when our little corner of the world is controlling the epidemic? Unfortunately, there isn’t a clear, definitive answer to this. What constitutes an epidemic is a little subjective, and it can be different for different diseases.

Epidemics are generally defined as an increase in the numbers of cases, in a given area, above some expected baseline. In some areas of the world that baseline might be zero, in other areas it could be hundreds of cases a month. Think of a disease like malaria. If we saw five cases in [North Carolina] in a week, which couldn’t be linked to recent travel, that would be alarming and could be a sign of the start of an epidemic. But in other parts of the world, five cases wouldn’t be unusual.

With that in mind, an epidemic is “over” when the number of new cases returns to whatever the normal baseline is for that disease in that area. In the case of COVID, the original baseline was zero for the whole world, but at this point I don’t know anyone who thinks we’re going to completely eliminate SARS-CoV-2 anytime soon. Since it’s a new disease, we don’t know what the baseline is. I think most are hoping that it will end up being something similar to seasonal flu, and it probably will, eventually. But how long that takes, no one knows.

What I think most people want to see, or would at least find an acceptable baseline, would be conditions where we have test positivity rates below 3%, infection rates below 0.7 [meaning the effective reproductive rate], and a 7-day average for new daily cases below 1 per 100,000. That will tell us we have it largely under control, but that doesn’t mean we’re done with it forever. If other states, or other countries, still have high numbers of cases it can always come back if we’re not careful. This isn’t really over anywhere until it’s over everywhere. And by over, I don’t mean gone forever, but rather just a seasonal virus akin to the flu.

Right now, we’re actually pretty close in [North Carolina]. We’re in the best shape we’ve been since June of last year. We’re on the right side of the line for test positivity rates, and we’re close on infection rates. The third, the 7-day average for new daily cases, is falling. Hopefully it keeps falling. We came close in late June of 2021. We got as close as 2.7 new cases per 100,000 in NC, but then behaviors changed, and Delta, and cases went up again. In fact, if we fall below 1 new case per 100,000 it will be the first time since March 27, 2020.

Swann: Great point about infections and numbers! I also look at hospitalizations. These were added by the CDC to metrics of transmission in communities. That is a great measure of the acute stress on the health care system, while the number of cases is important both for transmission and for risk of longer-term disease sometimes called “long COVID.” For the current metrics, low transmission in a particular community is fewer than 10 new COVID-19 admissions per 100,000 people and less than 10% of inpatient beds occupied by people with COVID-19.