Mouthwashes may reduce risk of coronavirus transmission, finds study

Researchers from Ruhr-Universität Bochum together with colleagues from Jena, Ulm, Duisburg-Essen, Nuremberg, and Bremen have found that COVID 19 can be inactivated using certain commercially available mouthwashes.

High viral loads can be detected in the oral cavity and throat of some Covid-19 patients. The use of mouthwashes that are effective against Sars-Cov-2 could thus help to reduce the viral load and possibly the risk of coronavirus transmission over the short term. This could be useful, for example, prior to dental treatments. However, mouth rinses are not suitable for treating Covid-19 infections or protecting yourself against catching the virus.

The results of the study are described by the team headed by Toni Meister, Professor Stephanie Pfänder and Professor Eike Steinmann from the Bochum-based Molecular and Medical Virology research group in the Journal of Infectious Diseases, published online on 29 July 2020. A review of laboratory results in clinical trials is pending.

Eight mouthwashes in a cell culture test

The researchers tested eight types of mouthwash with different ingredients that are available in pharmacies or drugstores in Germany. They mixed each mouthwash with virus particles and an interfering substance, which was intended to recreate the effect of saliva in the mouth. The mixture was then shaken for 30 seconds to simulate the effect of gargling. They then used Vero E6 cells, which are particularly receptive to Sars-Cov-2, to determine the virus titer. In order to assess the efficacy of the mouthwashes, the researchers also treated the virus suspensions with cell culture medium instead of the mouthwash before adding them to the cell culture.