WASHINGTON (NEXSTAR) — With so many people catching the coronavirus right now, it can feel like it’s only a matter of time before you’re exposed. Omicron cases are rocketing upward in what Dr. Anthony Fauci has called a “vertical spike,” and many are concerned about testing or isolation after meeting friends and family during the holidays.

If you’ve been called or texted that someone you know and saw recently tested positive—or if you were in close quarters with someone who said they were feeling ill—you may to quarantine before seeking a test. Dr. Peter Chin-Hong, an infectious disease expert at the University of California at San Francisco School of Medicine, said that it’s better to wait three to five days after exposure before testing. The rule of thumb applies to both polymerase chain reaction (PCR) tests and at-home rapid tests.

Figuring out testing options is unfortunately not very straightforward, and the CDC guidelines on who needs to quarantine and for how long can be confusing. Here’s what you need to know.

Isolate vs. quarantine

Do you have to isolate or do you have to quarantine? The difference here is mainly semantics. You isolate yourself from others if you’ve tested positive for COVID or if you’re experiencing symptoms. You quarantine yourself from others if you’ve been exposed to the virus but don’t know if you have it or not.

According to the CDC, isolation should only end if a person has been fever-free for at least 24 hours without the use of fever-reducing medications and if other symptoms are resolving.

Do you need to quarantine?

If you’ve tested positive for the virus, you ought to isolate for five days. But if not, the CDC says that not everyone who has had close contact with a COVID-positive person needs to quarantine. Specifically, they say that you don’t need to quarantine if:

  • You’re an adult (18 or older) and you’ve gotten all vaccines you’re eligible for, including boosters
  • You’re between 5 and 17 years old and have gotten two Pfizer shots
  • You’ve tested positive for the coronavirus in the past 90 days

Everyone else should self-quarantine if they’ve had close contact with a COVID case. “Close contact” is defined as being within 6 feet of someone for a cumulative 15 minutes in a 24-hour period.

How long do you need to quarantine?

CDC guidelines state you should quarantine away from others for five full days after your exposure. When quarantining, you should stay home and away from others, says the CDC. Wear a mask whenever you need to be around people in your household, if possible. For another five days after that, you should continue to monitor yourself for symptoms, then keep wearing a mask for another five days.

Do you need a negative COVID test to end quarantine?

If you still aren’t feeling any symptoms after five full days, the CDC says you should get tested for the virus. If you test negative, you can reenter the world. Just continue to wear a mask anytime you’re around other people and monitor yourself for fever or any other COVID symptoms until it has been 10 days since your exposure.

Because COVID tests are hard to come by right now, they are suggested to exit quarantine, but not required. If you can’t find a COVID test, the CDC says you can still re-enter the world after five days of quarantine, as long as you’re not feeling sick and keep wearing a mask for another five days.


A PCR test takes longer, because a lab has to process the sample, but it is more sensitive when it comes to the detection of early disease. Genetic tests, which use nasal swabs or saliva, can register bits of the coronavirus’ genetic material—as long as there is a good sample to work from.

The rapid antigen tests flying off drugstore shelves nationwide, give results in minutes but aren’t as accurate as a genetic test. The widespread use of at-home tests also has experts worried that the results—which are often not reported to health officials—may skew national tracking data.

If you’re planning on getting tested but are still waiting for the optimal window, Dr. Chin-Hong suggests wearing a mask to avoid inadvertently infecting others. CDC guidelines also state you should self-quarantine after exposure if you haven’t gotten a booster shot (and are eligible) or aren’t fully vaccinated.

What if I test positive or start feeling sick?

If you test positive or start to feel sick, it’s time to restart the clock and enter isolation. Stay home, get some rest, and find out how long to isolate.

Changing guidelines

The CDC on Tuesday explained a scientific rationale for shortening its isolation and quarantine recommendations. Officials changes follow evidence that people with the coronavirus are most infectious in the two days before and three days after symptoms develop.

Some experts have questioned how the new recommendations were crafted and why they were changed amid a spike in cases driven largely by the highly contagious omicron variant. Some also expressed dismay that the guidelines allowed people to leave isolation without getting tested to see if they were still infectious.

The Associated Press contributed to this report.