key: cord-0936567-vgay2y94 authors: Ramassy, Lindsay; Oumarou Hama, Hamadou; Costedoat, Caroline; Signoli, Michel; Verna, Emeline; La Scola, Bernard; Aboudharam, Gérard; Barbieri, Rémi; Drancourt, Michel title: Paleoserology points to Coronavirus as possible causative pathogens of the ‘Russian flu’ date: 2022-04-05 journal: Microb Biotechnol DOI: 10.1111/1751-7915.14058 sha: c5ab775879025db7e8160170bbf755f234e1b9c0 doc_id: 936567 cord_uid: vgay2y94 nan indirect paleomicrobiological diagnosis, and the hypothesis of an influenza stricto sensu caused by an Influenza virus has also been proposed (Dowdle, 1999) . We have recently applied paleo serological methods that we have previously developed (Oumarou Hama et al., 2020) to the exploration of male individuals who died from war-related injuries in August 1914 in Spincourt (Meuse, France) at the very beginning of the First World War; and who have potentially been exposed to 'Russian flu' on the basis of their birth date in France, between 1864 and 1894 (Verna et al., 2020) (Table 1) . The paleoserological methods we used, were based on extraction and characterization of immunoglobulins from the dental pulp contained in the teeth of deceased and buried individuals. Indeed, dental pulp contained dried blood as it was at the time of the individual's death (Barbieri et al., 2017 . Specifically, in this work, the mini-line blot method was applied to 29 pulp samples collected from 29 deceased individuals in Spincourt, as previously described (Raoult and Dasch, 1989; Oumarou Hama et al., 2020) . In the presence of a negative control consisting of skimmed milk, we tested the presence of antibodies against Coronaviruses including HCoV-229E alpha-Coronavirus, HCoV-OC43 beta-Coronavirus and SARS-CoV-2 beta-Coronavirus produced on cell culture tested negative for Mycoplasma spp. Coronavirus were heat-inactivated, a procedure shown to preserve antigenicity of the major Coronavirus antigens, specifically the spike protein antigenicity, as previously described a. Age was estimated via the evaluation of pubic symphysis morphology (Schmitt, 2008) and auricular surface of the pelvic bone (Schmitt, 2005) , in agreement with the French Army archives indicating that these soldiers were between 20 and 50 years (Verna et al., 2021) . (Edouard et al., 2021) . While negative controls remained negative, 1/29 paleoserum sample collected from soldier 521 showed reactivity against the Influenza viruses A and B contained in the 2020 vaccine (FluarixTetra, GSK vaccines, Brentford, UK) and 5/29 (24%) collected from soldiers 500, 508, 511, 512, 528 showed anti-Coronavirus reactivity; exhibiting area under curve > 500 units (determined on the basis of the negative and positive control area under curve values) against SARS-CoV-2 in one sample, 229E in two samples and OC43 in four samples; with the individual 528 exhibiting a significant reactivity against the three Coronaviruses (Fig. 1) . These very preliminary experimental results of a few samples support the hypothesis that a Coronavirus was responsible for the 'Russian flu', as derived from a review of the medical historical texts recently published (Br€ ussow and Br€ ussow, 2021) . Incorporation of pre-1890 samples may not guarantee them as negative controls, in the absence of further data regarding the antiquity of Coronaviruses and the absence of Coronavirus circulating in populations before 1890. However, due to extensive cross-reactivity between Coronaviruses, mainly supported by the relatively conserved nucleocapsid protein antigenicity, it was not possible to derive from our data, the exact Coronavirus species implied in the 'Russian flu'. Therefore, it is necessary to consolidate these indirect diagnostic data by incorporation of recombinant Coronavirus antigens into the mini-line blot assay; and in case of suspected ancient viremia to attempt direct diagnosis based on the detection of specific Coronavirus peptide sequences using paleoproteomics methods (Barbieri et al., 2017) , or even nucleotide sequences by metagenomics, in order to support the Coronavirus hypothesis in the controversial aetiology of 'Russian flu'. The authors have no conflicts of interest to declare. A 2,000-year-old specimen with intraerythrocytic Bartonella quintana Paleoproteomics of the dental pulp: The plague paradigm Clinical evidence that the pandemic from 1889 to 1891 commonly called the Russian flu might have been an earlier coronavirus pandemic Influenza A virus recycling revisited Automated Western immunoblotting detection of anti-SARS-CoV-2 serum antibodies An outbreak of relapsing fever unmasked by microbial paleoserology, 16th century, France Line blot and Western blot immunoassays for diagnosis of Mediterranean spotted fever Une nouvelle m ethode pour estimer l'âge au d ec es des adultes a partir de la surface sacro-pelvienne iliaque Une nouvelle m ethode pour discriminer les individus d ec ed es avant ou apr es 40 ans a partir de la symphyse pubienne Epidemic Influenza: Notes on its Origin and Method of Spread Transmissibility and geographic spread of the 1889 influenza pandemic Rapport de fouille et etude anthropologique des s epultures du cimeti ere franc ßais de Spincourt French soldiers who died during both World Wars: from recovery to repatriation