 Here, the authors perform plaque reduction neutralization, PRNT, assays quantitating SARS-CoV-2 specific neutralizing antibodies from 195 patients in different disease states and find that patients with severe disease exhibit higher peaks of neutralizing antibody titers than patients with mild or asymptomatic infections and that serum neutralizing antibody persists for over six months in most people. This article was authored by Eric H. Y. Lau, Owen T. Y. Zhang, David S. C. Hui, and others.