Abstract
BACKGROUND: The association between a robust or depressed antibody response and clinical severity of SARS remains unknown. OBJECTIVES: To study seroconversion and the magnitude of IgG responses in a SARS cohort with different disease severities. STUDY DESIGN AND METHOD: A retrospective analysis of all acute and convalescent-phase sera collected from a cohort of laboratory-confirmed SARS cases. Anti-SARS-CoV IgG antibody was detected using indirect immunofluorescence technique and quantified by two-fold serial dilutions. Characteristics of patients who seroconverted "early" (