TY - JOUR T1 - Nine Cases of SARS-CoV-2-PCR-positive Samples Showed No Increase of Antibodies Against SARS-CoV-2 JF - In Vivo JO - In Vivo SP - 2947 LP - 2949 DO - 10.21873/invivo.12587 VL - 35 IS - 5 AU - TAKAO KITAGAWA AU - MASANOBU KOBAYASHI AU - TOHRU OHTA AU - MASARU TERASAKI AU - YOKO TSUKAMOTO AU - RIE TAKAI AU - REIKA ISHIZUMI AU - OSAMU UEHARA AU - KOJI NAKAGAWA AU - KOZO AKINO AU - MASAHIRO ASAKA AU - YASUHIRO KURAMITSU Y1 - 2021/09/01 UR - http://iv.iiarjournals.org/content/35/5/2947.abstract N2 - Background/Aim: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been affecting Hokkaido, Japan since late February 2020 until present. The aim of this study was to report the relationship between anti-SARS-CoV-2 antibody-positive and SARS-CoV-2 PCR-positive cases by analyzing anti-SARS-CoV-2 antibodies (IgG and total-Ig). Patients and Methods: Serum samples were collected from care workers and nurses in two nursing homes and two hospitals which underwent virus outbreak. All people were confirmed to be SARS-CoV-2-positive by RT-qPCR and their sera was analyzed for anti-SARS-CoV-2 antibodies (IgG and total-Ig). Results: Although 34 out of 43 samples (79.1%) showed enough amount of anti-SARS-CoV-2 antibodies, 9 RT-qPCR -positive samples (20.9%) showed absence of anti-SARS-CoV-2 antibodies in their sera. Conclusion: The results that 20.9% of RT-qPCR-positive samples with SARS-CoV-2 showed absence of anti-SARS-CoV-2 antibodies provides a possibility that the innate immune reaction could eliminate the virus without activating adaptive immune reaction. ER -