3 ways to end a virus

The word itself comes from the Greek words pan (meaning all) and demos (meaning people), which makes sense: a key feature of a pandemic is that it can affect just about everyone. More common definitions include:

  • an outbreak of a disease that occurs over a wide geographic area (multiple countries or continents) and typically affects a significant proportion of the population (Merriam-Webster Medical Dictionary)
  • a sudden outbreak that becomes widespread and affects a whole region, a continent, or the world due to a susceptible population (MedicineNet.com)
  • a disease prevalent throughout an entire country, continent, or the whole world (dictionary.com)

These standard definitions aren’t particularly specific; what, exactly, does “multiple countries” or “a whole region” mean? How prevalent (widespread) does a disease have to be to be considered a pandemic?

And even if we could all agree on its definition, no single person, government agency, or public health organization has the authority to declare that a pandemic has begun or ended.

Some people have suggested a pandemic is over when everyone is behaving as though it is: no more precautions, restrictions, or changes in behavior compared with the period of time before these started. But if that’s true, people growing weary of restrictions, or those skeptical about their value, could ignore recommendations and create the impression that the pandemic is over — even as significant numbers of daily cases and deaths continue in the US and worldwide. That seems to be where we are with COVID right now.

Many pandemics eventually become endemic, meaning the infection is still present in a region or population but its behavior is predictable and the numbers of cases and deaths no longer spike. Learning to live with a virus is a key feature of an endemic virus; think flu or even the common cold. But it’s probably true that the transition from pandemic to endemic can only be recognized after it happens.