COVID-19 has taught us the meaning of the word “pandemic”: an outbreak of disease on a global scale.
There’s a good chance, however, that COVID-19 may evolve into something completely different: an endemic disease, where an illness is always present in a community, a population, or — in the case of COVID-19 — everywhere in the world.
Perhaps ironically, the rapid spread of the Omicron variant could help push COVID-19 into endemic status as soon as a few months from now, experts say.
There are predictions that the current Omicron surge will peak in the United States by mid-January. Some experts note that cases have declined significantly in South Africa, where the variant was first reported in late November.
“To get from a pandemic to endemic, the population level of immunity has to rise to herd immunity,” Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University in Tennessee and medical director of the National Foundation for Infectious Diseases, told Healthline. “The more contagious the virus, the higher level of herd immunity you need to tamp it down until it just smolders.”
The Omicron variant is spreading so rapidly and widely that it’s conceivable that enough people will have some degree of immunity via vaccination or past infection, and the COVID-19 pandemic could begin to fizzle.
“If we don’t have a new variant that shows up, then we could have some level of endemic by early 2022,” said Schaffner.
“COVID-19 will likely become an endemic disease,” said Erica Susky, an infection control and hospital epidemiology expert based in Toronto, Canada.
“If a disease does not become endemic, the only other scenario is for the disease to be eliminated,” Susky told Healthline. “With all that is occurring in the current pandemic, it is evident that SARS-CoV-2 is excellent at human-to-human transmission, cannot be ceased in transmission with any of our current public health measures, and will continue to circulate, likely indefinitely.”
Experts are looking at Omicron as the potential pathway to endemic status because it spreads easily but does not seem to be quite as deadly as some past variants.
“An effective pathogen that continues to spread is a pathogen that does not kill or seriously harm a large portion of infected individuals. Therefore, a living host who can function rather normally while infected is a host that can spread a viral pathogen to more new hosts,” explained Susky.
“There are still a large number of people in the world who have not yet [contracted] SARS-CoV-2,” Susky said. “A virus can become endemic once a large portion of the world’s population have some immunological memory from infection or vaccination. People with some level of immunological memory will spread the virus less readily, as their immune response will stop viral replication.”
“Life will move on and the world will learn to live with COVID-19,” said Susky. “The pandemic will not end with a bang, but will fade out.”
Learning to live with endemic COVID-19
Living in a world with endemic COVID-19 would not be too different from how society deals with other endemic diseases, such as influenza, said Schaffner.
In both cases, “New strains can show up and cause a certain amount of disease,” he said. “Each year we cope with that by getting as many people vaccinated as possible.”
One major difference, however, is that while flu outbreaks tend to be seasonal, COVID-19 is likely to circulate in the population year-round, noted Schaffner.
Some societal and public health changes wrought by COVID-19 are probably here for good. Periodic boosters are likely to be required, said Schaffner.
Outbreaks of endemic disease will also continue to strain the healthcare system and economy, much as bad flu seasons do.
Widespread vaccination and testing will also be required to prevent COVID-19 from returning to epidemic levels, particularly as new strains emerge.
“Waning vaccination may mean that we need annual vaccinations (in the early fall) to maintain higher levels of protection, and to respond to new variants as they emerge,” Sean Clouston, PhD, an epidemiologist and associate professor of public health at Stony Brook University in New York, told Healthline. “But flu shots show us that this is difficult and people do not always get them, so we should anticipate regular winter waves [of COVID-19].”
Zoom meetings and work-from-home arrangements are not the only cultural changes that will remain if and when COVID-19 becomes endemic. Low-key holiday celebrations may also be an enduring vestige of the pandemic.
“Some pre-COVID cultural events, such as holiday parties [or] New Year’s parties, are at high risk because they merge high risk activities with high risk times,” Clouston noted. “Maybe larger outdoor gatherings will be common in warmer seasons followed by smaller, more intimate, gatherings in the winter.”
When outbreaks occur, public health measures such as mask wearing, physical distancing, and even lockdowns may need to be restarted for a period of time — and likely will be accompanied by the now-familiar pushback from COVID-19 skeptics, Schaffner said.
Mask wearing, in particular, is likely to remain commonplace, especially in settings where older or immunocompromised individuals are present, such as hospitals and nursing homes.
“In Asia, wearing masks during flu season has been common for decades,” said Schaffner. “We used to think it was weird here. Now we’ve adapted to it.”
“When COVID-19 surges are not occurring, there will likely be some public health measures in place to mitigate transmission with the goal of allowing regular activities to occur even with COVID-19 in the community,” said Susky. “The hope is that some public health measures may be longer lived, for example, paid time away from work if one is sick, more social acceptance of masking when ill or in public places, and working from home if possible.”