As more and more people are diagnosed with COVID-19, the question of how long immunity to SARS-CoV-2, the virus that causes the illness, lasts, is increasingly important. Understanding that would help patients know whether they can get re-infected, and potentially even help doctors to better understand what type of protection we can expect from vaccines. Previous research found that levels of antibodies in recovered patients start to wane about three months from when those patients first experience symptoms.