What Does ‘Endemic’ Covid Mean? The Experts Don't Agree

(Bloomberg Opinion) -- Predicting how Covid-19 will behave next remains notoriously hard. Predicting how humans will react is much easier, since history can be a guide. 

One of the most prescient articles written about the pandemic’s future was Gina Kolata’s May 2020 New York Times article “How Pandemics End,” with historians of medicine describing society’s reactions to Ebola, bubonic plague and the 1918 flu pandemic. There’s a biological end to a pandemic, when cases and death rates fall, and a social end, when people get tired of being afraid, accept a certain amount of risk, and resume social and commercial life. The social end sometimes comes first. 

After two years of living with Covid, it’s not surprising that many folks are far less fearful of the virus and are eager to go back to a more normal existence. People want a word to describe the better future we envision. In 2020, we talked about herd immunity. In 2022, we say “endemic” instead.

Hopes for herd immunity faded when the delta variant spread through vaccinated populations, and omicron pushed that hope further away. And so “endemic” caught on. A weary public needs the emotional crutch, though it’s a wobbly one, since even the experts disagree about what it means. 

Oxford University biologist Aris Katzourakis has been arguing that the term endemic is being used in a misleading way to imply the pandemic will end without any more effort on our part. In a piece for Nature titled, “Covid-29: Endemic Doesn’t Mean Harmless” he called it one of the most misused terms of the pandemic. 

He said endemicity refers to a state in which the total number of infections is not dropping or growing — though an endemic disease can have big, predictable seasonal fluctuations. And endemic diseases can be deadly and disruptive. Colds are endemic but so is malaria, which kills 600,000 people a year. “You can be endemic and low prevalence or endemic and high prevalence and it can be harmful or not harmful and still be endemic,” he said. 

And endemicity doesn’t always last. A disease like the flu can be pandemic or endemic. When new strains jump from animals, flu can cause a pandemic, as H1N1 did in 2009. But now that same flu has stabilized and is considered endemic. The same virus can be described either way depending on its behavior at the time.

“Endemic” doesn’t mean it’s time to go back to normal. “Endemicity … isn’t a promise of safety. Instead, as epidemiologist Ellie Murray has argued, it’s a guarantee of having to be on guard all the time,” wrote journalist Maryn McKenna recently in Wired.

But people won’t be on guard all the time. Instead, some will continue in a state of perpetual anxiety. Others long ago reverted to ordinary life and other concerns. But that’s no reason to think the fight against this virus is winding down. 

What public health authorities can do now is apply two years of learning to impose interventions that are humane, sustainable, life-saving and protective against new variants. One step is making more and better vaccines, as well as antiviral medications, and getting them to poorly vaccinated parts of the globe. Though there’s some disagreement about how new variants arise, the primary suspect is unvaccinated people with conditions such as undertreated HIV, where the virus can multiply and evolve over weeks or months.

New protocols for rapid tests could protect nursing homes and make hospitals and doctors’ offices safer. Salaried workers around the world need better sick leave and gig workers, a safety net. It’s something that physician Muge Cevik in the UK has been advocating since spring of 2020, when she saw how many people with severe disease had been unable to skip work for even a few days.

Moving toward healthier buildings with good ventilation could prevent illness and death — as Harvard University’s Joseph Allen has been arguing. After championing universal masking early in the pandemic, he told me last fall that we have to start looking to solutions that can be sustained and that have multiple benefits.

Another researcher from the Harvard School of Public Health, William Hanage, has been arguing that we might not see a steady, predictable amount of disease for some time. To prepare for a future with more waves and lulls, we need better surveillance and data.

Data on surges and outbreaks could be more uniform, reliable, and accessible, as physician and researcher Eric Topol has argued. People would take precautions when it was most urgent. It’s unrealistic to expect people to change their lives to avoid infection indefinitely.

We don’t know how the virus will act in the future, but there’s a long history to tell us how people will act. Whether we use “endemic” or find some other term to describe the post-crisis phase of Covid-19, there are ways to keep up the fight with measures aimed at protecting human beings the way we are, and have always been, rather than some idealized version that public health officials wish we could be.

More From Other Writers at Bloomberg Opinion:

• Why Are Doctors Still Scrambling for Covid-19 Drugs?: Lisa Jarvis
• We’ll All Have Some Covid-19 Immunity Soon: Justin Fox
• Why Some Vaccinated People Resist Omicron and Others Don’t: Faye Flam

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Faye Flam is a Bloomberg Opinion columnist and host of the podcast "Follow the Science." She has written for the Economist, the New York Times, the Washington Post, Psychology Today, Science and other publications.

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