This study highlights the importance of testing antibodies against SARSCoV after the first week. ICMR has endorsed antibody testing for the current COVID-19 pandemic in hotspots/cluster, in symptomatic ILI (influenza-like illness), after seven days of illness (version 4, dated 09.04.2020). WHO has advised the use of rapid antibody tests only for disease surveillance and epidemiologic research.
Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, et al. Antibody responses to novel coronavirus disease 2019. Clin Infect Dis. 2020 Mar 28
Article Link: PUBMEDIndications and tests-Antibody response for diagnosis