(CNN) — The US Centers for Disease Control and Prevention (CDC) announced last week key changes to its national guidelines against covid-19. Among them was the end of mandatory quarantine after someone is exposed to close contact with the coronavirus. The CDC also revised the isolation guidance for people infected with covid-19.
With the end of the required quarantine, what should people do if they have been exposed? How long should they isolate if they get infected? What is the reason for making the changes? And are there exceptions? Who should take precautions beyond the new recommendations?
To guide us through the changes, I spoke with CNN medical analyst Dr. Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She is also the author of “Lifelines: A Doctor’s Journey in the Fight for Public Health“.
CNN: Did the CDC really end the quarantine? That seems like an important step.
Dr. Leana Wen: Quarantine has effectively ended for people exposed to covid-19. I agree, this is a major change in the recommendations.
The new guidance says that someone exposed to a person with Covid-19 no longer needs to be quarantined at home, away from others. They can go to work, attend school, and be in other settings with people, as long as they wear a High-quality mask that fits well, ideally an N95 or equivalent. People must mask for 10 days after their exposure. They must also take the test at least five days after exposure. If it’s positive, if they have covid-19, they need to isolate. If it’s negative, they should continue blinding for the full 10 days.
CNN: Can you remind us of the difference between quarantine and isolation?
Wen: Quarantine applies to someone who has been in close contact with a person infected with the coronavirus. Close contact, according to the CDC, means you have been within 2 meters of someone with covid-19 for a total of 15 minutes or more during a 24-hour period. Early in the pandemic, recommendations were that people exposed to covid-19 should self-quarantine from others and not be in public. This is how someone in need of “quarantine” was defined, as someone who has not been diagnosed with covid-19 but has significant exposure.
Now someone with known exposure no longer needs to be in quarantine, but they do need to have a 10-day masking period.
On the other hand, someone should be in isolation if they have been diagnosed with covid-19. Isolation is defined as being physically separated from others to prevent transmission of the virus during the infectious period.
CNN: Are there still some people who should take extra precautions, even though the guidelines remove quarantine?
Wen: Yes. The CDC says that exposed people should take extra precautions when around people who are more likely to get seriously ill from COVID-19. What I take this to mean is that you need to be more cautious if, for example, you are visiting an elderly grandparent.
If your spouse has the virus right now and you and your children do not, you could still go to work and your children to school wearing a mask, but consider postponing travel to see family members at medical risk until after the 10-day window. . If you live at home with vulnerable people, keep your distance during the 10-day period after your exposure and make sure everyone is indoors with each other.
CNN: What do people need to know now about isolation?
Wen: Here, the new CDC guidance is a bit complex.
The basic premise is that people diagnosed with covid-19, either symptomatic or asymptomatic, they must be isolated for at least five days. These first five days are the period when you are most likely to be contagious. The CDC emphasizes that you should try to stay home and separate yourself from others if possible. Do not travel and do not go to places where you cannot wear a mask, such as a restaurant where you will be eating.
If you have no symptoms, or if you have symptoms and they are improving and you remain fever-free for at least 24 hours, you can end isolation after five days. For the next five days, you must still wear a mask in public places. Therefore, you can go to work, but continue to wear a mask at work and make sure you do so while traveling on the train or bus.
There are some caveats here. First, the CDC guidance says that if you had moderate illness, defined as shortness of breath or difficulty breathing, or required hospitalization, or are immunocompromised, you should isolate until day 10. This makes sense, because more severe illness or having a compromised immune system suggests you might have had a higher viral load that takes longer to clear.
Second, the CDC is once again emphasizing caution with people who are likely to become seriously ill from COVID-19. If you just had covid-19, you should wait until at least after the 10th to visit medically fragile family or friends. I would also add here that you must have a negative rapid antigen test before seeing vulnerable people indoors. This is not something the CDC recommends, but I think the negative test adds more peace of mind to protect people at high risk.
Third, speaking of testing, the new guidance also says that you could end your 10 days of masking early if you take two quick tests 48 hours apart. Let’s say that by day five, her rapid test is negative. She could take another test on day seven and, if it’s negative, she no longer needs to wear a mask after that.
I think this is sensible, and in fact, I wish the CDC would be even more explicit with their recommendation to remove evidence-based isolation. There are some people who will still test positive on day 11. Here I am referring only to the rapid antigen test at home, since the PCR test could remain positive for much longer. I think it would be even safer to say that you should test negative before being around vulnerable people, even if it’s been, say, 12 or 13 days.
CNN: What about people who start testing positive again after testing negative for the first time, the so-called “rebound” phenomenon? Does the clock reset for them?
Wen: Good question, and yes it does. This “rebound” phenomenon is often associated with taking the antiviral Paxlovid, but could occur in people who are not taking treatments. CDC guidance says that if someone tests positive again, the clock is reset and the day they test positive a second time is day zero again. That means they still have to go through five days of isolation and mask until after day 10, just like they did the first time.
CNN: Why were these changes made? Has the science changed or is the CDC responding to public pressure?
Wen: I think there are two factors. One is the recognition that covid-19 is here to stay. We will probably live with this virus for our lifetime and the lifetime of our children and beyond. Since that is the case, the emphasis must be on resuming normality, which means removing policies that disrupt daily life.
The other factor is that public health has to respond to where the public is. Most Americans have returned to many aspects of life before the pandemic. The CDC guidelines seem to pick up people where they already are, and, for some, don’t go far enough—for example, they still recommend wearing masks in high-transmission areas, even though most people don’t. For public health to be trusted, it must be considered relevant, and if CDC guidance is too far removed from people’s everyday behavior, it will not be trusted.
It is implied here that there is no new research leading to change. Quarantine is not removed because covid-19 has become less infectious. However, circumstances have changed, including the fact that we have many more tools that reduce the likelihood of serious illness from the coronavirus.
All in all, I think the CDC made the right decision. Relaxing restrictions now preserves the credibility of public health officials later, if stricter guidance needs to be put in place due to a new and more dangerous variant.