What Doctors Really Mean When They Say COVID-19 Is Most Likely ‘Endemic’

On Tuesday, the United Kingdom’s government chief scientific adviser, Sir Patrick Vallance, stated plainly his doubts that COVID-19 will ever disappearing entirely. “We can’t be certain, but I think it’s unlikely we will end up with a truly sterilizing vaccine, [that is] something that completely stops infection, and it’s likely this disease will circulate and be endemic, that’s my best assessment,” he said. The notion that COVID-19 maybe be an endemic disease might make you feel uneasy, but what does it really mean for the future health of human populations?

In this context, the meaning of the word “endemic” differs from epidemic and even pandemic in that it refers to the “constant presence” of a disease in certain geographic locations, explains the U.S. Centers of Disease Control and Prevention (CDC). It’s used as an adjective, while both “pandemic” and “epidemic” are nouns. An epidemic refers to a (typically) sudden rise in the number of cases of a disease above what is normally expected whereas a pandemic refers to an “epidemic that has spread over several countries or continents, usually affecting a large number of people,” says the CDC.

In this context, the meaning of the word “endemic” differs from epidemic and even pandemic in that it refers to the “constant presence” of a disease in certain geographic locations.

Since COVID-19 has left no corner of Earth untouched, it has earned its classification as a pandemic—but Vallance argues that it might eventually take the route of other diseases and become endemic in the near future. Malaria is one such example of an endemic disease, says Erika Schwartz, MD, a doctor of preventative medicine. Since the type of mosquito that carries the disease thrives in the humid climates of Central and South America, the Caribbean, parts of Africa, and Southeast Asia, those who live in such areas have come to view it as a part of life (similar to the way North America and Europe understand flu season). Soon, says Dr. Schwartz, many countries could be living with some version of COVID-19 indefinitely.

Not all endemic diseases last forever in every geographic region, says Dr. Schwartz. Part of the job of Public Health Officials is to determine how to cut off the source of the disease so that it no longer ravages a given area. “The vector of malaria is this mosquito. But if you dry the swamp, you can eliminate the vector,” says Dr. Schwartz. “Malaria was endemic in Florida at one point. What they did to get rid of it is, they dried the swamp, they got rid of the mosquitoes, and so now malaria isn’t endemic in Florida.”

Unfortunately, in the case of COVID-19, people are the vector (or the living organisms with the ability to transmit infectious pathogens between humans, or between animals and other animals). That means that when it comes to tackling an endemic COVID-19 in future years, we will need to treat it very much the same way we treat the flu: by getting your yearly vaccinations (when a safe COVID-19 vaccine is available), washing your hands, and generally caring for your health with exercise and diet.

Right now, we don’t yet know where and if COVID-19 will become endemic—but that doesn’t mean we can’t start prioritizing these best practices (like wearing a mask and washing your hands) today.

So, when will this end? Answers from an epidemiologist: