Recently, the Biden Administration unveiled plans to not renew the state of emergency declaration for the Covid-19 pandemic, effectively ending the three year public health emergency when it expires in May. Details on the Department of Health and Human Services’ transition plan can be found here if you are interested. With Covid restrictions in several countries being discontinued over the past few months, it would seem policy makers are considering the Covid pandemic to be at its end. But if one were to ask a scientist if the pandemic is over, the answer would be less straightforward. To understand where we stand, let’s discuss.
Definition of Pandemic
To give the short answer; no, the pandemic isn’t over. Experts agree that Covid-19 still poses a significant risk to the public, particularly to vulnerable groups. Globally, Covid deaths have ticked upward since December and the WHO still considers the pandemic to be a public health emergency.
Longer answer; that depends what one means by pandemic. The official definition of a pandemic is “an outbreak of disease that occurs over a wide geographical area.” By this metric, a pandemic ends once it becomes an endemic disease. I’ve given the epidemiological definition of endemic disease in the past, as I have also discussed why that’s not necessarily a useful definition as it relates to public health. Mathematically, an endemic disease is just a disease that doesn’t spread exponentially, meaning each generation of the disease produces the same or fewer infected people than the previous one. The problems with this definition from a practical standpoint is twofold; firstly, unless one can monitor every infected person on Earth and those people they interacted with who also got sick, determining the precise Re of a disease is next to impossible. More importantly, a disease can still be a major threat even if it isn’t spreading exponentially. If a disease has already infected a million people, then even if each generation is half the size of the previous, it will still take twenty generations for the virus to burn itself out and will infect an additional one million people. This also ignores the severity of the disease’s symptoms and the complexities of seasonal diseases such as the flu, whose Re changes over the course of the year. It's important to recognize that these mathematical measurements are very useful in identifying diseases that could become large-scale outbreaks or in identifying when a pandemic has started. However, a purely mathematical answer is too simple to inform health policy decisions on when a pandemic has ended.
When health agencies, political leaders, or the general public describe a pandemic, they usually mean “a state of emergency caused by an infectious disease,” so the end of a pandemic would be when the disease stops being an emergency. To this end, many health officials have observed that a pandemic ends when society or government reaches a point where it accepts the continued death toll. This is…also not a great definition, as these same health officials will tell you. Not only is the concept of acceptable death toll already problematic morally speaking, but we’ve seen with this pandemic the degree to which political rhetoric can shape what the public sees as an acceptable loss. There are segments of our government and general populus for whom Covid-19 was never an emergency, so long as they themselves or their loved ones weren’t infected. A definition based on public opinion is going to be too subjective to be useful. Add in the complete lack of scientific basis for this definition, and I would argue it’s a less useful definition than the previous one. Viruses don’t seem too bothered by public opinion.
A better way to think about the end of an emergency, one that would consider both science and public opinion, might be “when things return to normal.” A better definition perhaps, but one could argue it rests once again on a nebulously defined concept; what does one mean by normal? If by normal we mean “when everything goes back to the way it was,” then the pandemic will never end. Not only will SARS-CoV-2 exist in humanity’s viral ecosystem indefinitely, but the adaptations we’ve made and the lessons we’ve learned from the pandemic should also count as irrevocable changes to our society. Normal is impossible because everything changes. On the other end of the spectrum, defining normal as “when we can behave as we could before the pandemic,” I would argue the pandemic has been over for a while. Speaking personally, all of the activities I could do before the pandemic I can perform just as well by wearing a mask or testing beforehand. One’s mileage may vary on whether these things preclude our current status quo counting as ‘normal,’ but again, that creates a scenario where ‘pandemic’ becomes a subjective description.
In-between these two extremes we have what I believe to be a good definition, “at what point can public health, political, and scientific institutions deal with the consequences of an infectious disease with the same effort and resources they could perform any of their standard tasks?’ The pandemic could be said to be over when treating the sick and tracking new strains becomes business as usual, either because the job becomes easier or because these institutions adapt.
By this Definition…
So by this definition, can the Covid-19 pandemic be said to be at an end? Hard to say, but probably not quite. Covid-19 still causes 200,000 new infections and 1,000 deaths per day globally. For comparison, this past flu season caused an average of 300 infections and 14 deaths per day. This infection rate is high enough that new strains continue to emerge regularly, keeping Covid from disappearing. Fortunately, Covid’s effective reproduction number has dropped below 1 for most of the world, so the number of cases is trending downward even if there are still spikes. None of the new variants have produced a significantly more dangerous illness, but it’s difficult to determine if this is due to an evolutionary quirk or pure luck. Hospital overcrowding is still an issue in many regions,* but ICU crowding specifically has been declining. Health officials agree the pandemic will almost certainly end sometime in 2023, though that is still a wide range.
As many have said, the long-term fate of Covid is likely to become a seasonal virus akin to the flu, with annual flare-ups and new strains requiring updated vaccinations. Since we’ve been dealing with seasonal flu reasonably well for over fifty years, it stands to reason we could deal with seasonal coronaviruses just as well with the same scientific infrastructure. While Covid infection rates have been at their highest in the winter, this seasonality has yet to occur. New Covid strains have emerged at all times of the year and it’s difficult to tell at this time if this is because Covid is so widespread at the moment or if Covid evolves that much faster than flu. Some experts have put forth that Covid won’t become a seasonal illness and it’s long-term fate will instead be a low-but constant infection rate throughout the year. Again, it’s too early to tell for sure, but a seasonal cycle would be preferable for the development of variant vaccines. It should also be noted that Covid-19 is a more dangerous virus than flu, with a mortality rate 10 times higher depending on how it’s calculated, so the pressure that would be on this infrastructure would necessarily be higher.
Health officials seem to be of mixed opinion on whether or not the Biden administration’s end to the pandemic’s state of emergency is premature or not. At the very least, it’s important to realize that just because Covid is no longer an emergency does not mean it’s no longer a threat. Flu is something our society can deal with routinely, but it still killed 5,000 people in the United States this past year. The end of a state of emergency needs to be married to planning and infrastructure to deal with Covid on a permanent basis, and time will tell if the administration’s transition plan is sufficient to do so. For now, remember to get the most up-to-date Covid booster, wear a mask if you’re in a particularly crowded area such as a plane, arena, or public transportation, and quarantine if you feel sick. We’re definitely nearing the end of the pandemic, even if such an end is less black-and-white than anticipated.
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*Hospital overcrowding is still high for several reasons unrelated and tangentially related to Covid, including the rise in other diseases, and the exodus of health care workers due to burnout and low pay. Hospital overcrowding is thus a questionable statistic for measuring pandemic severity, though ICU overcrowding is a better metric.
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