On January 4, 2022, the U.S. Centers for Disease Control and Prevention (CDC) provided additional guidance in the wake of its December 27, 2021, update to recommended quarantine and isolation periods.

The CDC now recommends that anyone with COVID-19 isolate “for at least 5 full days,” starting on the first full day after symptoms begin or the first day of a positive test if the individual is asymptomatic. If the individual is fever free for 24 hours without the use of fever-reducing medication and other symptoms have improved, the individual can end isolation but should continue to wear a mask around others and avoid travel and high-risk individuals and settings through day 10. The new guidance states that individuals with severe COVID-19 symptoms and immunocompromised individuals should isolate for “at least 10 and up to 20 days” in consultation with their healthcare providers.

The CDC did not recommend testing for isolation as it does for quarantine situations but provided guidance for those who wish to test. The CDC stated that “the best approach” for individuals wishing to test is to use an antigen test toward the end of the 5-day isolation period if they “are fever free for 24 hours without the use of fever-reducing medication and … other symptoms have improved.” If the test is positive, the CDC recommends continuing isolation through day 10. The CDC notes that “antigen tests should be used twice over a three-day period with at least 24 hours and no more than 48 hours between tests.”