'Endemic' Disease Meaning Explained as Experts Predict COVID Could Become One

In March 2020, the World Health Organization (WHO) characterized the COVID outbreak as a pandemic, and some public health experts have since predicted that the disease will become endemic over time.

But what is the meaning of endemic in this context?

An endemic disease is one that is always present in a given region or population. These diseases occur at relatively consistent rates with patterns that are somewhat predictable.

Endemic diseases don't have to be present at high levels, and can even be rare in some circumstances.

Examples of Endemic Diseases

Some examples of common endemic diseases include rhinoviruses, which cause the common cold in many parts of the world. Malaria is endemic to certain regions of Central and South America, Africa, Asia, Eastern Europe and the South Pacific.

Other well known examples include influenza and hepatitis B, which are endemic around the world, and HIV/AIDS—considered to be endemic to parts of Africa.

Some public health experts are predicting that COVID will become endemic, although when this might happen is unclear and it could vary depending on the location.

Pandemic, Epidemics and Outbreaks

COVID has been characterized as a pandemic by the WHO. A pandemic is declared when a new disease is spreading worldwide.

Pandemics differ from epidemics—defined as outbreaks of diseases within a restricted geographical area. The spread of Ebola within three West African countries between 2014 and 2016 was characterized as an epidemic, for example.

An outbreak is generally defined as a spike in cases of a given disease—more than what is normally expected—with a small and specific location, and usually over a short period of time.

While the timeline and exact pathway is still uncertain, many experts have predicted that COVID can't now be eradicated at the global level and will become endemic, continuing to circulate in pockets of the population for years to come, causing sporadic outbreaks in regions where it had been eliminated.

In a survey conducted earlier this year by the journal Nature, around 90 percent of more than 100 immunologists, infectious disease researchers and virologists working on SARS-CoV-2, the virus that causes COVID-19, said they expected the disease to become endemic. However, one-third said it might be possible to eliminate the virus from certain parts of the globe.

As more of the global population acquires immunity—either through exposure to the virus or by vaccination—the impact of the disease will become less severe. It's also expected that countries won't enter the endemic phase all at the same time due to a host of variables, including vaccination rates and environmental factors.

Reevaluating COVID

Some European leaders have suggested that it's already time to reevaluate COVID and treat it like an endemic illness. Spain's prime minister, Pedro Sanchez, has called on the European Union to do so, for example.

"The situation is not what we faced a year ago," Sanchez said in a radio interview with Spain's Cadena SER on Monday. "I think we have to evaluate the evolution of Covid to an endemic illness, from the pandemic we have faced up until now."

Previously, U.K. prime minister Boris Johnson had told the British public that the country would have to "learn to live with the virus." The British government hasn't introduced significant new restrictions despite a huge winter spike in COVID cases fueled by the Omicron variant—that now appears to have peaked.

On Sunday, U.K. Education Secretary Nadhim Zahawi told the BBC that the country was on the road "from pandemic to endemic."

These comments were echoed by professor David Heymann from the London School of Hygiene and Tropical Medicine, who said at a seminar on Monday that the U.K. is the "closest of any country in being out of the pandemic if it isn't already out of the pandemic and having the disease as endemic."

WHO officials have said it is still to soon to characterize COVID as an endemic disease and that the world is still firmly in the pandemic stage.

"In terms of endemicity, we're still a way off, and I know there's a lot of discussion around that right now," Dr. Catherine Smallwood, a senior emergency officer at WHO Europe, said at a press conference on Tuesday. "Endemicity assumes that there's stable circulation of the virus, at predictable levels and potentially known and predictable waves of epidemic transmission."

"But what we're seeing at the moment coming into 2022 is nowhere near that, we still have a huge amount of uncertainty, we still have a virus that's evolving quite quickly and posing new challenges so we're certainly not at the point of being able to call it endemic. It might become endemic in due course but pinning that down to 2022 is a bit difficult at this stage."

A crowded street in Cologne, Germany
A crowded street in Cologne, Germany, during the fourth wave of the COVID-19 pandemic on December 22, 2021. Public health experts predict that COVID-19 could become an endemic disease. Andreas Rentz/Getty Images