Five days. That’s how long you should isolate after testing positive for COVID before going back to normal life (while wearing a mask in public for five more days), according to the U.S. Centers for Disease Control.

The CDC’s five-day quarantine policy for COVID cases is not law, but families, human resource departments, schools, and other institutions across the country depend on its advice for deciding how to return to normal life after a COVID infection.

Scientists have questioned the scientific rationale behind the policy since the CDC introduced it late last year. And now critics have more data to back up their claims: Viral shedding can occur beyond 10 days in even healthy, vaccinated adults, according to a preprint out of London published this month.