Can You Get Covid Twice? What Reinfection Cases Really Mean

Does getting Covid-19 prevent you from getting it again? How well and for how long people are protected by an immune response to the SARS-CoV-2 virus will affect transmission of the virus and shape the course of the pandemic. Although some research shows reinfection is rare, especially among younger adults, fast-spreading variants first reported in Brazil and South Africa appear to increase the risk.

A tracker maintained by the Dutch news agency BNO News recorded 72 confirmed cases globally as of mid-April 2021. That compares with more than 143 million confirmed Covid-19 cases in total. On April 22 Singapore reported 10 suspected cases at a dormitory. Reports of reinfections are biased toward detecting people who develop the symptoms of Covid-19, meaning more asymptomatic infections may be occurring but aren’t being detected. Researchers in Denmark used the country’s vast national health network to look more systematically for reinfections among about 4 million people (or 69% of the population) who underwent 10.6 million tests in 2020. According to a study published March 17 in the Lancet medical journal, 0.65% of people who tested positive for SARS-CoV-2 during Denmark’s first Covid-19 surge returned a positive test again during the second wave.