See full answer CDC is aware of recent reports indicating that persons who were previously diagnosed with COVID-19 can be re-infected. These reports can understandably cause concern. The immune response, including duration of immunity, to SARS-CoV-2 infection is not yet understood. Based on what we know from other viruses, including common human coronaviruses, some reinfections are expected. Ongoing COVID-19 studies will help establish the frequency and severity of reinfection and who might be at higher risk for reinfection. At this time, whether you have had COVID-19 or not, the best ways to prevent infection are to wear a mask in public places, stay at least 6 feet away from other people, frequently wash your hands with soap and water for at least 20 seconds, and avoid crowds and confined spaces.