Pelleau S, Woudenberg T, Rosado J, et al. - Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a complex antibody response that differs by orders of magnitude between individuals and over time. In this study, a multiplex serological test was developed for determining antibodies to five SARS-CoV-2 antigens and the Spike proteins of seasonal coronaviruses. In cohorts of hospitalized patients and healthcare workers, 36% of anti-Spike IgG remained, 31% (9%, 89%) anti-RBD IgG remained, and 7% (1%, 31%) anti-Nucleocapsid IgG remained 1 year after symptoms. Along with diagnosing prior SARS-CoV-2 infection, multiplex serological assays can aid in determining the time since infection which can be utilized to reconstruct past epidemics.