TY - JOUR TI - Back to basics in COVID-19: Antigens and antibodies—Completing the puzzle AU - Neagu, M. AU - Calina, D. AU - Docea, A.O. AU - Constantin, C. AU - Filippini, T. AU - Vinceti, M. AU - Drakoulis, N. AU - Poulas, K. AU - Nikolouzakis, T.K. AU - Spandidos, D.A. AU - Tsatsakis, A. JO - Journal of Cellular and Molecular Medicine PY - 2021 VL - 25 TODO - 10 SP - 4523-4533 PB - Blackwell Publishing Inc. SN - 1582-1838, 1582-4934 TODO - 10.1111/jcmm.16462 TODO - angiotensin converting enzyme 2; antibody; antigen; carbon tetrachloride; corticosteroid; dipeptidyl peptidase IV; helicase; hemagglutinin; immunoglobulin A; immunoglobulin enhancer binding protein; immunoglobulin G; immunoglobulin M; influenza vaccine; interferon; interleukin 10; macrophage inflammatory protein 1alpha; neutralizing antibody; RANTES; tumor necrosis factor; vitronectin; virus antibody; virus antigen, adult respiratory distress syndrome; asthma; blood brain barrier; CD4+ T lymphocyte; clinical outcome; coronavirus disease 2019; enzyme linked immunosorbent assay; epidemic; gene mutation; health care system; hepatitis C; hospitalization; immune response; immune system; immunization; influenza; intensive care unit; Middle East respiratory syndrome coronavirus; molecular epidemiology; protein phosphorylation; regulatory T lymphocyte; Review; risk factor; septic shock; seroprevalence; social distancing; virus infection; virus load; virus replication; animal; diagnosis; epidemiology; genetics; human; immunological memory; immunology; mutation; pandemic, Animals; Antibodies, Viral; Antigens, Viral; COVID-19; COVID-19 Testing; Humans; Immunologic Memory; Mutation; Pandemics; SARS-CoV-2 TODO - The outbreak of the coronavirus disease 2019 (COVID-19) has gathered 1 year of scientific/clinical information. This informational asset should be thoroughly and wisely used in the coming year colliding in a global task force to control this infection. Epidemiology of this infection shows that the available estimates of SARS-CoV-2 infection prevalence largely depended on the availability of molecular testing and the extent of tested population. Within molecular diagnosis, the viability and infectiousness of the virus in the tested samples should be further investigated. Moreover, SARS-CoV-2 has a genetic normal evolution that is a dynamic process. The immune system participates to the counterattack of the viral infection by pathogen elimination, cellular homoeostasis, tissue repair and generation of memory cells that would be reactivated upon a second encounter with the same virus. In all these stages, we still have knowledge to be gathered regarding antibody persistence, protective effects and immunological memory. Moreover, information regarding the intense pro-inflammatory action in severe cases still lacks and this is important in stratifying patients for difficult to treat cases. Without being exhaustive, the review will cover these important issues to be acknowledged to further advance in the battle against the current pandemia. © 2021 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd. ER -