California and Oregon recently became the first states to break with the US Centers for Disease Control and Prevention on how long a person infected with Covid-19 should isolate, saying that people who test positive are no longer expected to isolate for at least five days — and those without symptoms don’t have to isolate at all.
CDC is considering a shift to its Covid-19 isolation guidance to say that people no longer need to isolate once they have been fever-free for 24 hours and their symptoms are mild or improving, according to the Washington Post.
In a statement Tuesday, the agency told CNN that there were no changes to announce at this time.
“We will continue to make decisions based on the best evidence and science to keep communities healthy and safe,” spokesperson Dave Daigle said.
Wastewater surveillance data published by the CDC suggests that Covid-19 is still circulating at high levels across the US, and experts emphasize that until any new recommendations are announced, most people should continue to follow the CDC’s current guidance: isolating for at least five days after you test positive for Covid-19 then wearing a mask until at least 10 days after a positive test. If you’re not fever-free for 24-hours without taking fever-reducing medications at day five, you should isolate longer.
Some states shift isolation guidelines
Even if the CDC changes its guidance, state health departments can still implement their own.
People who test positive for Covid-19 in California and Oregon are no longer expected to isolate for a set period of time. Those without symptoms don’t have to isolate at all, and those with symptoms can return to school or work once their symptoms are improving and they’ve been fever-free for at least 24 hours, according to the state policies.
“Most school systems and most places of employment will go along with whatever the state is recommending,” said Dr. Peter Hotez, who co-directs the Center for Vaccine Development at Texas Children’s Hospital. “You’re more or less obligated for to follow that guideline.”
Health officials in those states say the changes to their isolation guidelines reflect policy that’s evolving along with the pandemic. Both California and Oregon still encourage people who test positive to wear a mask around others for at least 10 days.
Dr. Carlos del Rio, a professor of medicine in the Division of Infectious Diseases at the Emory University School of Medicine, said the CDC may take a similar step as evidence shows infections becoming milder.
The CDC notes that “infections are causing severe disease less frequently than earlier in the pandemic.”
Changes to CDC’s guidance could bring Covid-19 in line with other respiratory viruses, such as flu and RSV.
“We need to start ending Covid exceptionalism and incorporate Covid into our respiratory viruses,” del Rio said. “At the end of the day, there’s going to be a similar approach to all these viruses.”
Some infectious disease experts also believe that a change would better align with how many Americans are already treating the virus.
“Currently, many of our citizens are no longer testing for Covid-19 and are not actively isolating,” said Dr. Clay Marsh, West Virginia’s Covid-19 czar. “With the caveat of the risk of long Covid and the potential for mortality in the elderly and immunocompromised, the future guidance by CDC meets the standard we are seeing.”
West Virginia currently recommends that people who’ve tested positive for Covid isolate for at least five days, according to the state’s Department of Health.
Hotez isn’t a fan of ending isolation for people who don’t have symptoms, particularly because Covid-19 is generally more severe than the flu and because asymptomatic Covid-19 cases are more common.
He says he would like to see the CDC recommend using a home test after you have gone 24 hours without a fever.
“If you have an antigen test and if you’re negative, then you can leave isolation,” he proposed. If you test positive, you would keep isolating until you got a negative test.
“Home antigen tests give you an idea of how much virus you’re actually shedding,” he said. “That’s the kind of thing the CDC needs to look at.”
But in order to make a proper recommendation, Hotez says, the CDC would need to gather data on how many people test positive for Covid-19 after a 24-hour period with no fever.
Experts say Covid-19 vaccinations — which are helpful in preventing the spread of the virus as well as severe illness or death — could also lessen the need for isolation if they were utilized more.
“You’re isolating because you’re worried that you’re shedding virus,” Hotez said. “People forget that vaccinations can have a big effect on reducing the amount of virus shedding.”
The latest Covid-19 shot was rolled out in September. It’s a monovalent vaccine formulated to target newer variants of the virus that are currently circulating.
But not enough Americans are getting the updated vaccine, Hotez and del Rio say, exposing older adults and people with weakened immune systems to severe infection.
“I think we really need to focus on what we can do to prevent cases and what we can do to prevent severe disease,” del Rio said.
What’s the CDC’s current guidance?
For now, the agency continues to recommend isolating for at least five days after you test positive for Covid-19, while keeping a distance from other people in your household. This means staying home from school and work for about a week.
Get CNN Health's weekly newsletter
- Sign up here to get The Results Are In with Dr. Sanjay Gupta every Friday from the CNN Health team.
If your symptoms are improving and you are fever-free for 24 hours without taking any fever-reducing medications like acetaminophen, you can end isolation on day five, the CDC says. If your symptoms are not improving by day five, continue to isolate until you feel better, and your fever is gone.
After ending isolation, you should continue to wear a high-quality mask around other people until at least 10 days after the positive test, according to the agency. You may stop wearing a mask earlier if you have two negative tests 48 hours apart.
If you had shortness of breath or trouble breathing, isolate for at least 10 days, the CDC says. The same applies to people who were hospitalized or who have a weakened immune system; these patients should talk to their doctor before ending isolation.
CNN’s Jamie Gumbrecht, Brenda Goodman, Deidre McPhillips and Meg Tirrell contributed to this report.