TY - JOUR T1 - SARS-CoV-2 in-vitro neutralization assay reveals inhibition of virus entry by iota-carrageenan JF - bioRxiv DO - 10.1101/2020.07.28.224733 SP - 2020.07.28.224733 AU - Martina Morokutti-Kurz AU - Philipp Graf AU - Andreas Grassauer AU - Eva Prieschl-Grassauer Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/07/28/2020.07.28.224733.abstract N2 - In the absence of a vaccine and other effective prophylactic or therapeutic countermeasures the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) remains a significant public health threat. Attachment and entry of coronaviruses including SARS-CoV-2 is mediated by the spike glycoprotein (SGP). Recently, a SARS-CoV-2 Spike Pseudotyped Lentivirus (SSPL) was developed that allows studying spike-mediated cell entry via luciferase reporter activity in a BSL2 environment. Here, we show that iota-carrageenan can inhibit the cell entry of SSPL in a dose dependent manner. SSPL particles were efficiently neutralized with an IC50 value of 2.6 µg/ml iota-carrageenan. In vitro data on iota-carrageenan against various Rhino- and Coronaviruses showed similar IC50 values and translated readily into clinical effectiveness when a nasal spray containing iota-carrageenan demonstrated a reduction in severity and duration of symptoms of common cold caused by various respiratory viruses. Accordingly, our in vitro data on SSPL suggest that administration of iota-carrageenan may be an effective and safe prophylaxis or treatment for SARS-CoV-2 infections.Competing Interest StatementAll authors are employees of Marinomed Biotech AG. Marinomed Biotech AG. Authors Eva Prieschl-Grassauer and Andreas Grassauer are co-founder of Marinomed Biotech AG and inventors of patents held by Marinomed Biotech AG that relate to the content of the manuscript. ER -