Probably, although we’re not yet absolutely sure. In an August 16, 2020 statement, the U.S. Centers for Disease Control and Prevention (CDC) said it does not know if someone can be re-infected with COVID-19. The agency reported that individuals who have recovered from the infection may have low levels of the virus in their bodies for up to three months after being diagnosed. If so, they may continue to test positive, even though they are no longer infectious.
The CDC also noted that there have been no confirmed reports of a person being re-infected with COVID-19 within 3 months of an initial infection, although research on this possibility is ongoing. Therefore, individuals who have recovered and develop new COVID-19 symptoms may need to be tested for reinfection, especially if they have had close contact with someone currently infected.
Available CDC data indicate that individuals with mild to moderate COVID-19 remain infectious for up to 10 days after symptoms begin, while those with more severe illness probably remain so for up to 20 days. The agency also noted that recovered persons can continue to shed detectable viruses for up to three months after they first became ill, although they are unlikely to infect anyone. These findings strengthen the justification for relying on a symptom-based, rather than test-based, strategy for ending isolation of these patients, so that persons who are no longer infectious are not kept unnecessarily isolated. As stated above, so far reinfection with COVID-19 has not been definitely confirmed in anyone who has recovered.
Until we know more, CDC recommends that all of us, whether or not we have had COVID-19, continue to take precautions in order to avoid becoming infected and to avoid infecting someone else: wash hands regularly, stay at least 6 feet away from others whenever possible, wear a mask, and self isolate if you develop symptoms.
Bottom line: the latest research suggests that lasting immunity to COVID-19 appears to occur even in people who have had only mild infections.
Andrew Weil, M.D.
U.S. Centers for Disease Control and Prevention “Updated Isolation Guidance Does Not Imply Immunity to COVID-19,” August 14, 2020.