de Oliveira-Filho, Edmilson Fde Carvalho, Otávio VCarneiro, Ianei OFernandes, Fagner D'ambrosoVaz, Sara NunesPedroso, CéliaGonzalez-Auza, LilianUrbieta, Victor CarvalhoKühne, ArneMayoral, RafaelaJo, Wendy KMoreira-Soto, AndrésReusken, Chantal B E MDrosten, ChristianBrites, CarlosOsterrieder, KlausNetto, Eduardo MartinsRistow, Luiz EduardoMaia, Rita de CassiaVogel, Fernanda S Floresde Almeida, Nadia RossiFranke, Carlos RobertoDrexler, Jan Felix2022-04-252022-04-252022-04-053545007010.3389/fimmu.2022.857322http://hdl.handle.net/10029/625741Carnivores such as cats and minks are highly susceptible to SARS-CoV-2. Brazil is a global COVID-19 hot spot and several cases of human-to-cat transmission have been documented. We investigated the spread of SARS-CoV-2 by testing 547 domestic cats sampled between July-November 2020 from seven states in southern, southeastern, and northeastern Brazil. Moreover, we investigated whether immune responses elicited by enzootic coronaviruses affect SARS-CoV-2 infection in cats. We found infection with significantly higher neutralizing antibody titers against the Gamma variant of concern, endemic in Brazil during 2020, than against an early SARS-CoV-2 B.1 isolate (p<0.0001), validating the use of Gamma for further testing. The overall SARS-CoV-2 seroprevalence in Brazilian cats during late 2020 validated by plaque reduction neutralization test (PRNT90) was 7.3% (95% CI, 5.3-9.8). There was no significant difference in SARS-CoV-2 seroprevalence in cats between Brazilian states, suggesting homogeneous infection levels ranging from 4.6% (95% CI, 2.2-8.4) to 11.4% (95% CI, 6.7-17.4; p=0.4438). Seroprevalence of the prototypic cat coronavirus Feline coronavirus (FCoV) in a PRNT90 was high at 33.3% (95% CI, 24.9-42.5) and seroprevalence of Bovine coronavirus (BCoV) was low at 1.7% (95% CI, 0.2-5.9) in a PRNT90. Neutralizing antibody titers were significantly lower for FCoV than for SARS-CoV-2 (p=0.0001), consistent with relatively more recent infection of cats with SARS-CoV-2. Neither the magnitude of SARS-CoV-2 antibody titers (p=0.6390), nor SARS-CoV-2 infection status were affected by FCoV serostatus (p=0.8863). Our data suggest that pre-existing immunity against enzootic coronaviruses neither prevents, nor enhances SARS-CoV-2 infection in cats. High SARS-CoV-2 seroprevalence already during the first year of the pandemic substantiates frequent infection of domestic cats and raises concerns on potential SARS-CoV-2 mutations escaping human immunity upon spillback.enCopyright © 2022 Oliveira-Filho, de Carvalho, Carneiro, Fernandes, Vaz, Pedroso, Gonzalez-Auza, Urbieta, Kühne, Mayoral, Jo, Moreira-Soto, Reusken, Drosten, Brites, Osterrieder, Netto, Ristow, Maia, Vogel, Almeida, Franke and Drexler.SARS-CoV-2cats (felis catus)coronaviruscross-reactivityserologyzoonosisArticle1664-3224Frontiers in immunology