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 1Marinomed Biotech AG, Korneuburg, 2100, Austria; 2Institute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany; 3Biostatistik & Consulting Savli, Hartberg, 8230, Austria; 4Practice Dr. Friedrich Ehrenreich, Vienna, 1170, AustriaCorrespondence: Martina Morokutti-KurzMarinomed Biotech AG, Korneuburg, 2100, AustriaEmail martina.morokutti-kurz@marinomed.comUlrich SchubertInstitute of Virology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, GermanyEmail ulrich.schubert@fau.dePurpose: 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 concentration 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 IC 90 was exceeded by 121-fold (p < 0.001).Conclusion: Sucking an iota-carrageenan containing lozenge releases sufficient iota-carrageenan 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, SARS-CoV-2