Validation of serological methods for COVID-19 and retrospective screening of health employees and visitors to the São Paulo University Hospital, Brazil - Santos, Robert Andreata; Machado, Rafael Rahal Guaragna; Alves, Rúbens Prince dos Santos; Sales, Natiely Silva; Soares, Camila Pereira; Rodrigues, Karine Bitencourt; Andrade, Juliana Bannwart; Fock, Ricardo Ambrósio; Margarido, Paulo Francisco Ramos; Guzzo, Cristiane Rodrigues; Boscardin, Silvia Beatriz; Durigon, Edison Luiz; et al. (Frontiers in Cellular and Infection Microbiology, 2022)