COVID is now endemic, the CDC says. What does that mean for Philly?

Four years out from the outbreak of the COVID-19 pandemic, life is largely back to normal in Philadelphia, with residents treating COVID illness as a reality that’s here to stay.

The Centers for Disease Control and Prevention have indicated they agree, with an official telling NPR recently that the agency considers the virus endemic — in other words, a disease with a constant and predictable presence.

But some epidemiologists in Philadelphia and around the country are not convinced. They note the virus is still relatively unpredictable. The unexpectedly high surge in cases this summer is a prime example, they say.

“Everyone has accepted COVID as a common respiratory viral infection — maybe too much,” said Neil Fishman, chief medical officer of the Hospital of the University of Pennsylvania.

» READ MORE: In new recommendations, the CDC says COVID patients can end isolation 24 hours after symptoms improve

The Inquirer asked local public health experts about endemic disease, how COVID might not fit the definition, and what Philadelphians can do to avoid getting sick as cases rise. Here’s what we learned:

In a pandemic, a newer virus or infection sweeps through a very large population. By contrast, a virus that is endemic sees a predictable ebb and flow of cases every year. “The best examples are influenza, which occurs in late fall and early winter, and RSV, which has the same seasonality,” Fishman said.

But just because a disease is endemic does not mean that it’s not dangerous, he cautioned.

“People forget that 40,000 people a year die of influenza in the United States,” he said.

COVID killed about 50,000 people in the United States in 2023, making it the 10th-leading cause of death. In 2022, it was the fourth-leading cause of death, and the third-leading cause of death from March 2020 to October 2021, ABC News reported this week.

“Endemic doesn’t mean benign. It’s still a serious disease,” Fishman said.

No. Even if most people are behaving like COVID is endemic, that doesn’t mean that the disease is affecting the public in predictable cycles like the flu does, some scientists say.

Fishman thinks it may take another five years or longer for COVID to settle into a truly predictable pattern of seasonal illness.

“It might take a little longer for COVID to become truly endemic because of its ability to mutate,” he said.

Many epidemiologists had noted a decrease in COVID cases the last two summers and were expecting to see similar drops this year. Instead, cases have surged, with the CDC reporting that infections are “growing or likely growing” in 32 states as of Aug. 6.

“It still fluctuates a lot,” said Thersa Sweet, an associate teaching professor of epidemiology at Drexel University. “We wouldn’t have expected it to have an increase like we’re seeing now, but we are.”

“I’d say it’s sort of endemic. It’s here, it’s not going away, but we are still seeing unpredictable surges.”

NPR reported that the endemic distinction will not change the CDC’s recommended health response to the virus, including advising people to stay home when they’re sick and get vaccinated to prevent the spread of the disease.

It’s still important for public health agencies to continue to monitor how the virus spreads and which variants are circulating, said Shara Epstein, the medical director of the Philadelphia health department’s Division of Disease Control.

“Scientists will continue to work to develop new and better vaccines and treatments,” she said in a statement. “And individuals can help keep themselves and their communities safe by receiving updated vaccines and staying home when they are sick.”

The amount of COVID detected in wastewater — now the most accurate way to track the virus since most cases are no longer reported to health agencies — has been rising nationally since May. Current nationwide viral activity levels are close to where they were in January.

“We are seeing high levels of virus around the country, and Philadelphia is no exception,” Epstein said.

Wastewater tested from three sites in Philadelphia show COVID’s presence in the city has been slowly increasing since the spring, though deaths and hospitalizations have remained low.

Viral activity levels in the rest of the state have also been rising; the CDC says activity levels are currently “high” in Pennsylvania and in Delaware. (Viral activity is currently “moderate” in New Jersey, according to the agency.)

A number of factors might be contributing to the spike. “These are guesses on my part, but we keep seeing these new variants that pop up that are more infectious,” Sweet said. “That’s probably the biggest reason why it’s so unpredictable.”

Vaccination rates are still low for the latest COVID vaccines, released last fall and designed to provide immunity against newer variants of the virus. According to the CDC, about 25% of Philadelphians above the age of 18 had received their new vaccinations as of May, in line with state and national vaccine uptake.

The CDC calling COVID endemic means little in daily life.

“I’ve had COVID recently — I have no idea where I got it,” Fishman said. “People are sick and not staying home, they’re riding public transportation, they’re going to work and transmitting disease to others.”

People should wash their hands, stay home when they’re sick, and consider masking on public transportation and in other enclosed spaces, Fishman said. He regularly masks on public transportation; the latest public health guidance lists masks as a preventative measure people can take in addition to the CDC’s core recommendations for preventing COVID. Those include vaccination, good hygiene, and seeking medical treatments like Paxlovid if you’re at high risk for serious complications.

New COVID vaccines are expected in the fall, which will add protection against the newer COVID variants circulating.