CDC officials acknowledged in internal discussions and in a briefing last week with state health officials how much the COVID-19 landscape has changed since the virus emerged four years ago, killing nearly 1.2 million people in the United States and shuttering businesses and schools. The new reality — with most people having developed a level of immunity to the virus because of prior infection or vaccination — warrants a shift to a more practical approach, experts and health officials say.

“Public health has to be realistic,” said Michael T. Osterholm, an infectious-disease expert at the University of Minnesota. “In making recommendations to the public today, we have to try to get the most out of what people are willing to do. … You can be absolutely right in the science and yet accomplish nothing because no one will listen to you.”

The CDC plans to recommend that people who test positive for the coronavirus use clinical symptoms to determine when to end isolation. Under the new approach, people would no longer need to stay home if they have been fever-free for at least 24 hours without the aid of medication and their symptoms are mild and improving, according to three agency officials who spoke on the condition of anonymity to share internal discussions.

The federal recommendations follow similar moves by Oregon and California. The White House has yet to sign off on the guidance that the agency is expected to release in April for public feedback, officials said. One agency official said the timing could “move around a bit” until the guidance is finalized.

Work on revising isolation guidance has been underway since last August, but was paused in the fall as COVID cases rose. CDC Director Mandy Cohen sent staff a memo in January that listed “Pan-resp guidance-April” as a bullet point for the agency’s 2024 priorities.

Officials said they recognized the need to give the public more practical guidelines for COVID-19, acknowledging that few people are following isolation guidance that hasn’t been updated since December 2021. Back then, health officials cut the recommended isolation period for people with asymptomatic coronavirus from 10 days to five because they worried essential services would be hobbled as the highly transmissible omicron variant sent infections surging. The decision was hailed by business groups and slammed by some union leaders and health experts.

The plan to further loosen isolation guidance when the science around infectiousness has not changed is likely to prompt strong negative reaction from vulnerable groups, including people older than 65, those with weak immune systems and long COVID patients, CDC officials and experts said.

Doing so “sweeps this serious illness under the rug,” said Lara Jirmanus, a clinical instructor at Harvard Medical School and a member of the People’s CDC, a coalition of health-care workers, scientists and advocates focused on reducing the harmful effects of COVID-19.

Public health officials should treat COVID differently from other respiratory viruses, she said, because it’s deadlier than the flu and increases the risk of developing long-term complications. As many as 7% of Americans report having suffered from a slew of lingering COVID symptoms, including fatigue, difficulty breathing, brain fog, joint pain and ongoing loss of taste and smell, according to the CDC.

The new isolation recommendations would not apply to hospitals and other health-care settings with more vulnerable populations, CDC officials said.

While the coronavirus continues to cause serious illness, especially among the most vulnerable people, vaccines and effective treatments such as Paxlovid are available. The latest versions of coronavirus vaccines were 54% effective at preventing symptomatic infection in adults, according to data released Feb. 1, the first U.S. study to assess how well the shots work against the most recent coronavirus variant. But CDC data shows only 22% of adults and 12% of children had received the updated vaccine as of Feb. 9, despite data showing the vaccines provide robust protection against serious illness.

Coronavirus levels in wastewater indicate that symptomatic and asymptomatic infections remain high. About 20,000 people are still hospitalized — and about 2,300 are dying — every week, CDC data show. But the numbers are falling and are much lower than when deaths peaked in January 2021 when almost 26,000 people died of COVID each week and about 115,000 were hospitalized.

The lower rates of hospitalizations were among the reasons California shortened its five-day isolation recommendation last month, urging people to stay home until they are fever-free for 24 hours and their symptoms are mild and improving. Oregon made a similar move last May.

California’s state epidemiologist Erica Pan said the societal disruptions that resulted from strict isolation guidelines also helped spur the change. Workers without sick leave and those who can’t work from home if they or their children test positive and are required to isolate bore a disproportionate burden. Strict isolation requirements can act as a disincentive to test when testing should be encouraged so people at risk for serious illness can get treatment, she said.

Giving people symptom-based guidance, similar to what is already recommended for flu, is a better way to prioritize those most at risk and balance the potential for disruptive impacts on schools and workplaces, Pan said. After Oregon made its change, the state has not experienced any disproportionate increases in community transmission or severity, according to data shared last month with the national association representing state health officials.

California still recommends people with COVID wear masks indoors when they are around others for 10 days after testing positive — even if they have no symptoms — or becoming sick. “You may remove your mask sooner than 10 days if you have two sequential negative tests at least one day apart,” the California guidance states.

It’s not clear whether the updated CDC guidance will continue to recommend masking for 10 days.

Health officials from other states told the CDC last week that they are already moving toward isolation guidelines that would treat the coronavirus the same as flu and RSV, with additional precautions for people at high risk, said Anne Zink, an emergency room physician and Alaska’s chief medical officer.

Many other countries, including the United Kingdom, Denmark, Finland, Norway and Australia, made changes to isolation recommendations in 2022. Of 16 countries whose policies California officials reviewed, only Germany and Ireland still recommend isolation for five days, according to a presentation the California public health department gave health officials from other states in January. The Singapore ministry of health, in updated guidance late last year, said residents could “return to normal activities” once coronavirus symptoms resolve.

Even before the Biden administration ended the public health emergency last May, much of the public had moved on from COVID-19, with many people having long given up testing and masking, much less isolating when they come down with COVID symptoms.

Doctors say the best way for sick people to protect their communities is to mask or avoid unnecessary trips outside the home.

“You see a lot of people with symptoms — you don’t know if they have COVID or influenza or RSV — but in all three of those cases, they probably shouldn’t be at Target, coughing, and looking sick,” said Eli Perencevich, an internal medicine professor at the University of Iowa.