Paleoserological detection of Coronavirus antigens in dental calculus of human remains dating from the beginning of the 19th century, French Ardennes.

OBJECTIVE: Vanishing viral RNA restricts our ability to detect ancient pathogens, so, we used paleo serological approaches to trace the dynamics of the Coronavirus in ancient populations. MATERIALS AND METHODS: We investigated 10 ancient dental calculus samples collected from a cemetery dated to the beginning of the 19th century and excavated in Charleville-Mézières. After paleoserum samples were extracted from dental calculus, paleoserology using mini-line-blot incorporating one alpha-Coronavirus (Coronavirus 229 E) and two beta-Coronavirus (Coronavirus OC 43, SARS-CoV-2) antigens and controls was completed by an automated Western blotting assay. RESULTS: Once appropriate controls had validated the data, mini-line-blot detected antibodies against the two beta-Coronavirus antigens in individuals US1300 and US1339, automated Western blotting confirming one beta-Coronavirus antigen for individual US1300 and an additional individual US1326. DISCUSSION: Combing mini-line blot and automated Western blot assays made it possible to detect immunoreactive immunoglobulin tracing circulation of Coronavirus in France at the very beginning of the 19th century.