There has been so much confusion and conflicting answers to questions of whether having immunity to COVID-19 is long-lasting, especially if you have mild infection. The way to really answer this question is to deliberately infect people who have recovered from COVID-19 with the SARS-CoV-2 virus again
Covid-19 is an illness that doesn’t leave everyone free of symptoms after treatment and discharge from the hospital. Some suffer a second covid infection after what was thought to be an effective treatment regime.