COVID may be most infectious 2 or 3 days around symptom onset | CIDRAP

The greatest risk of transmission was 2 days before and 3 days after the index patient became ill, peaking on the day of symptom onset (adjusted relative risk [aRR], 1.3). This link was consistent, regardless of other factors such as exposure setting and duration or age and sex of the contact. Source: COVID may be most infectious 2 or 3 days around symptom onset | CIDRAP