Mouthwash could kill Covid - and may help to stop it from spreading

Some types of mouthwash could be used to halt the spread of coronavirus, as it may kill the virus, according to a new study.

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The chemical cetylpyridinium chloride, which is found in some mouthwashes, reportedly kills off 99.9 per cent of bacteria and pathogens in the mouth.

As such, it could be used to reduce the transmission of coronavirus through saliva droplets, due to the chemical’s virucidal effect.

Not conclusive

Covid-19 is commonly spread through saliva droplets, but the study suggests that certain types of mouthwash could kill the virus before it can be spread.

Researchers from multinational consumer goods company Unilever carried out the study, which is yet to be peer-reviewed.

Findings from the study are not yet conclusive, with researchers stating that “a fuller understanding of the potential of mouthwash to reduce viral counts” is an important topic that “warrants further laboratory and clinical assessment”.

However, Prof Valerie O’Donnell, co-director of the Systems Immunity Research Institute at Cardiff University, said that the initial results from the study are encouraging, but more work needs to be done, specifically to test the effectiveness of mouthwash in the human throat.

She said: “Our view is that the in vitro studies (including this one and also two other recent studies which showed the same for Listerine and PVP-I) are highly encouraging but so far, in vivo studies have not been published.

"The human oropharynx will be constantly producing viruses so we don’t know how long the effect would persist for - this is the main question.

“Recent studies in test tubes have as much as possible tried to mimic the conditions in the throat, but of course this isn’t the same as in vivo.”

Further trials

Another trial looking at the potential use of mouthwash is currently underway at the University Hospital of Wales in Cardiff.

Covid patients are taking part in a 12-week trial using Dentyl mouthwash to measure the effect on the levels of virus in their saliva. The results of the study are expected to be published early next year.