Abstract: International Journal of General Medicine Dovepress open access to scientific and medical research International Journal of General Medicine For personal use only. Open Access Full Text Article C L I N I C A L T R I A L R E P O RT The Saliva of Probands Sucking an Iota-Carrageenan Containing Lozenge Inhibits Viral Binding and Replication of the Most Predominant Common Cold Viruses and SARS-CoV-2 Martina Morokutti-Kurz 1 Nicole Unger-Manhart 1 Philipp Graf 1 Pia Rauch 2 Julia Kodnar 1 Maximilian Große 2 Christian Setz 2 Markus Savli 3 Friedrich Ehrenreich 4 Andreas Grassauer 1 Eva Prieschl-Grassauer 1 Ulrich Schubert 2 1 Marinomed Biotech AG, Korneuburg, 2100, Austria; 2Institute of Virology, Friedrich-Alexander University ErlangenNürnberg (FAU), Erlangen, Germany; 3 Biostatistik & Consulting Savli, Hartberg, 8230, Austria; 4Practice Dr. Friedrich Ehrenreich, Vienna, 1170, Austria Correspondence: Martina MorokuttiKurz Marinomed Biotech AG, Korneuburg, 2100, Austria Email martina.morokuttikurz@marinomed.com Ulrich Schubert Institute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany Email ulrich.schubert@fau.de Purpose: The aim of this study was to investigate whether sucking of an iota-carrageenan containing lozenge releases sufficient iota-carrageenan into the saliva of healthy subjects to neutralize representatives of the most common respiratory virus families causing common cold and SARS-CoV-2. Patients and Methods: In this monocentric, open label, prospective clinical trial, 31 healthy subjects were included to suck a commercially available iota-carrageenan containing lozenge. Saliva samples from 27 subjects were used for ex vivo efficacy analysis. The study’s primary objective was to assess if the mean iota-carrageenan concentration of the saliva samples exceeded 5 µg/mL, which is the concentration known to reduce replication of human rhinovirus (hRV) 1a and 8 by 90%. The iota-carrageenan concentration of the saliva samples was analyzed by UV-Vis spectroscopy. The antiviral effectiveness of the individual saliva samples was determined in vitro against a panel of respiratory viruses including hRV1a, hRV8, human coronavirus OC43, influenza virus A H1N1pdm09, coxsackievirus A10, parainfluenza virus 3 and SARS-CoV-2 using standard virological assays. Results: The mean iota-carrageenan concentration detected in the saliva exceeds the concentra­ tion needed to inhibit 90% of hRV1a and hRV8 replication by 134-fold (95% CI 116.3–160.8-fold; p < 0.001). Thus, the study met the primary endpoint. Furthermore, the iota-carrageenan saliva concentration was 60 to 30,351-fold higher than needed to reduce viral replication/binding of all tested viruses by at least 90% (p < 0.001). The effect was most pronounced in hCoV OC43; in case of SARS-CoV-2, the IC90 was exceeded by 121-fold (p < 0.001). Conclusion: Sucking an iota-carrageenan containing lozenge releases sufficient iota-carra­ geenan to neutralize and inactivate the most abundant respiratory viruses as well as pandemic SARS-CoV-2. The lozenges are therefore an appropriate measure to reduce the viral load at the site of infection, hereby presumably limiting transmission within a population as well as translocation to the lower respiratory tract. Trial Registration: NCT04533906. Keywords: iota-carrageenan, respiratory viruses, corona virus, lozenges, antiviral, clinical study,..