Mouse Anti-SARS-CoV-2 Nucleoprotein Monoclonal Antibody, clone NB1

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of human coronavirus disease 2019 (COVID-19), emerged in Wuhan, China, in December 2019. The virus rapidly spread globally, resulting in a public health crisis including almost 5 million cases and 323,256 deaths as of May 21, 2020. Here, we describe the identification and evaluation of commercially available reagents and assays for the molecular detection of SARS-CoV-2 in infected FFPE cell pellets. We identified a suitable rabbit polyclonal anti-SARS-CoV spike protein antibody and a mouse monoclonal anti-SARS-CoV nucleocapsid protein (NP) antibody for cross-detection of the respective SARS-CoV-2 proteins by IHC and immunofluorescence assay (IFA). Next, we established RNAscope in situ hybridization (ISH) to detect SARS-CoV-2 RNA. Furthermore, we established a multiplex FISH (mFISH) to detect positive-sense SARS-CoV-2 RNA and negative-sense SARS-CoV-2 RNA (a replicative intermediate indicating viral replication). Finally, we developed a dual staining assay using IHC and ISH to detect SARS-CoV-2 antigen and RNA in the same FFPE section. It is hoped that these reagents and assays will accelerate COVID-19 pathogenesis studies in humans and in COVID-19 animal models.

Background In China, mothers with confirmed or suspected COVID-19 pneumonia are recommended to stop breastfeeding. However, the evidence to support this guidance is lacking. There have been relatively few cases reported about direct breastfeeding an infant by a mother with SARS-CoV-2 pneumonia. Therefore, it is necessary to assess the safety of breastfeeding and the possible protective effects of breast milk on infants. Case presentation This report analyzes the case of a mother who continued breastfeeding her 13 month-old child when both were diagnosed with confirmed COVID-19 pneumonia. We describe the clinical presentation, diagnosis, treatment, and outcome. The presence of SARS-CoV-2 nucleic acid was determined in maternal serum, breast milk, nasopharyngeal (NP) swabs and feces, and in infant serum, NP swabs and feces. IgM and IgG antibodies against SARS-CoV-2 were assessed in maternal serum and breast milk and in infant serum. SARS-CoV-2 nucleic acid was not detected in the breast milk, and antibodies against SARS-CoV-2 were detected in the mother's serum and milk. Conclusions The present case further confirms that the possibility of mother-to-child transmission about SARS-CoV-2 via breast milk alone was very small, and breast milk is safe for direct feeding of infants.