First the coronavirus was an epidemic, then it became a pandemic, and now we're starting to hear over and over again that it's on its way to becoming endemic. That means COVID will forever be part of our lives in some form, like how the Spanish flu of 1918 morphed over time into the common flus of today.

As we grapple with Delta rage, it's helpful to understand what endemic means when it comes to COVID both in terms of what we do in the present and what our day-to-day will look like in the future. For starters, even if COVID will eventually become endemic, it doesn't mean we should give up trying to contain the virus, public health experts have said. And if more of us get vaccinated now, and maybe one day annually, getting COVID may mean a few days of discomfort and then bouncing back to normal until we do it all again the following year.

"There will be a time in the future when life is like it was two years ago: You run up to someone, give them a hug, get an infection, go through half a box of tissues, and move on with your life," Emory University researcher Jennie Lavine told The Atlantic. "That’s where we’re headed, but we’re not there yet."

What does endemic mean?

When a disease spikes suddenly in a certain area, that's an epidemic. When that disease spreads uncontrollably into multiple countries, that's a pandemic. When it burrows so deep that it constantly hums along, albeit at controlled, predictable levels, that means it's endemic.

COVID "is too widespread now for us to stop or eradicate from humans, so it will very likely become an endemic disease," Dr. Rachel L. Roper, a professor at East Carolina University's medical school who has a doctorate in microbiology and immunology, wrote in an email.

Malaria and dengue are widely thought of as endemic in parts of Africa. The chickenpox is endemic worldwide. Respiratory syncytial virus, also known as RSV, is also endemic in the U.S. It looks like the common cold in most adults and older kids, but can be more serious for babies, potentially causing pneumonia, according to the Mayo Clinic.

With an epidemic, the risks are generally unclear at first, Harvard Immunologist Yonatan Grad told the university's communications team in a Q&A. If it were endemic, COVID would persist, but it'd spread less rapidly and we'd have systems in place to prevent it from sucking us under more relentless, pounding waves. To arrive at that scenario, we need more immunity and less transmission. Immunity comes from vaccinations and infections, but there is much more to learn about how long it lasts, and at what level, for both.

"Since viruses spread where there are enough susceptible individuals and enough contact among them to sustain spread, it’s hard to anticipate what the timeline will be for the expected shift of COVID-19 to endemicity," Grad explained. "It’s dependent on factors like the strength and duration of immune protection from vaccination and natural infection, our patterns of contact with one another that allow spread, and the transmissibility of the virus."

When will COVID be endemic?

Many virologists believe we're on our way to COVID becoming endemic, but when exactly we'll flip the switch from dealing with a pandemic to an endemic virus is unclear.

"It really is more of a process where we understand that there's not going to be uncontrolled community-based spread and that by allocating to COVID-19 the resources that we normally allocate to other endemic conditions [and] are sufficient to keep the infection under control," Dr. Brian Conway, medical director of Vancouver Infectious Diseases Centre, said, according to Canadian broadcaster Global News.

Of 119 immunologists, infectious disease researchers, and virologists surveyed earlier in 2021 by the science journal Nature, 89 percent believe COVID will likely or very likely be endemic. An epidemiologist at the University of Minnesota in Minneapolis, Michael Osterholm, told Nature: "Eradicating this virus right now from the world is a lot like trying to plan the construction of a stepping-stone pathway to the moon. It’s unrealistic."

It's possible that COVID diminishes in some parts of the world but stubbornly sticks around elsewhere, depending on local public health protocols. The higher the vaccine coverage, the more likely immunity can take hold in a region, Naturereports. For example, the measles have been eradicated from the U.S. as an endemic disease since 2000, but cases flares up now and then due to international travelers (and anti-vaccination misinformation). Remember the Disneyland measles outbreak from 2015?

It's rare for a disease to completely disappear. Two examples that have been eradicated, according to the World Health Organization, are: smallpox and rinderpest, or cattle plague. Vaccinations played an important part in cutting down both.

Isolation and quarantine stopped the spread of SARS in 2003, Roper said. Roughly 8,000 people were infected in 29 countries at the time, according to the CDC.

How come the vaccines haven't stopped COVID from becoming endemic yet?

Higher vaccination rates may in some areas eventually stop COVID, but that depends on how many people get vaccines, how long they last, and how effective they are at reducing transmission over time.

As public health officials keep saying, the vaccines are doing what they were expected to do: prevent death and hospitalizations. But not enough people have been vaccinated. We wish a drop of vaccine could magically make COVID go poof, but pharmaceutical companies aren't fairy godmothers.

COVID "will hopefully become pretty rare, certainly in the U.S. where we have effective vaccines widely available. But as long as there are people who won’t get vaccinated, it will continue to spread. The more unvaccinated people we have, the more it will spread," Roper added.

You are way more likely to get COVID if you're unvaccinated than if you're vaccinated, according to data compiled by KFF, a health research nonprofit.

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The number of unvaccinated globally remains high for a variety of reasons, including political schisms and distrust in the U.S., vaccine hoarding by rich countries, limited access in poorer countries, and logistical issues with some unable to take off work or get childcare when they get jabbed and have to deal with temporary flu-like side effects.

Only 23 percent of the world's population is fully vaccinated against COVID and 31 percent are partially vaccinated, according to Our World in Data, an online educational resource focused on global living conditions.

So does possible endemicity mean we should give up now?

Getting vaccinated, wearing masks, and social distancing in public spaces can help control overcrowding in hospitals and keep schools, restaurants, and other businesses open, according to The Atlantic. If you have disposable income, you can donate to help people around the world get vaccinated too. How often we have to wear masks or how far away we should stand away from each other depends on the situation, according to the CDC. It may be low risk to walk your dog outside alone without a mask. Same goes for two vaccinated people to stand next to each other and talk without masks on. But the risk increases when the pair chat in a crowded, indoor space surrounded by strangers whose vaccination status varies, healthcare officials have said.

"Even in situations where you have high vaccine coverage, if you've got a lot of transmissions then you wouldn't take your mask off," Dr. Michael Ryan, a WHO executive said at a press conference earlier this summer.

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Just because COVID may become endemic, doesn't mean we throw out our masks and stop fighting.

As Dr. Arrianna Planey, a medical geographer with a Ph.D. in geography and geographic information science, tweeted, "endemicity is not destiny."

UPDATE: Aug. 15, 2021, 5:25 p.m. PDT This post has been updated to include comments from Dr. Rachel L. Roper, a microbiology and immunology professor at East Carolina University's medical school and add information about RSV.