Scientists call for research into whether mouthwash could reduce Covid-19 spread

A group of scientists is calling for urgent research into whether readily available mouthwash could be effective in reducing the spread of coronavirus.

They conducted a review of the scientific research in the area to assess whether mouthwash could have the potential to reduce transmission in the early stages of Covid-19 infection.

SARS-CoV-2 is an enveloped virus with an outer fatty (lipid) membrane.

However, according to the researchers, so far there has been no discussion about the potential role of damaging this membrane as a possible way to inactivate the virus in the throat.

They say previous studies have shown that agents commonly found in mouthwashes – such as low amounts of ethanol, povidone-iodine and cetylpyridinium – could disrupt the lipid membranes of several enveloped viruses.

However, they stress that it is not yet known whether this could also be the case for this new coronavirus, and people should continue to follow Government guidance.

The researchers assessed existing mouthwash formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope – and suggested that several deserve clinical evaluation.

Publishing their review in the Function journal, the authors wrote: "We highlight that already published research on other enveloped viruses, including coronaviruses, directly supports the idea that further research is needed on whether oral rinsing could be considered as a potential way to reduce transmission of SARS-CoV-2."

They said research to determine the potential of this approach could include evaluating existing – or specifically tailored – formulations of mouthwash in the lab and then in clinical trials.

Monitored population-based trials could be undertaken with appropriate commercially available brands, the researchers added.

Lead author Professor Valerie O'Donnell, co-director of Cardiff University's Systems Immunity Research Institute, said: "Safe use of mouthwash – as in gargling – has so far not been considered by public health bodies in the UK.

"In test tube experiments and limited clinical studies, some mouthwashes contain enough of known virucidal ingredients to effectively target lipids in similar enveloped viruses.

"What we don't know yet is whether existing mouthwashes are active against the lipid membrane of SARS-CoV-2.

"Our review of the literature suggests that research is needed as a matter of urgency to determine its potential for use against this new virus.

"This is an under-researched area of major clinical need – and we hope that research projects will be quickly mobilised to further evaluate this."

Professor O'Donnell added: "Mouthwash has not been tested against this new coronavirus yet.

"People should continue to follow the preventive measures issued by the UK Government, including washing hands frequently and maintaining social distance.

"This study suggests further clinical studies could be worthwhile based on the theoretical evidence."

The researchers from Cardiff University's School of Medicine, along with the universities of Nottingham, Colorado, Ottawa, Barcelona and Cambridge's Babraham Institute, included virologists, lipid specialists, microbicide and healthcare experts, while industry partners provided global formulation information.