New Study Claims Human Coronavirus "Inactivated" By Mouthwash and Oral Rinses

A new study conducted by researchers at the Penn State College of Medicine has found that a common dental item can inactivate human coronaviruses: mouthwash and oral rinses. In other words, we haven't yet tested in people the effects of using products like mouthwash on coronaviruses.

The team's findings bolster past research that also looked at how oral rinses and mouthwashes may be able to reduce the viral load of human coronaviruses.

Although the researchers didn't specifically test SARS-CoV-2 in the study, this particular virus is genetically related to the other human coronaviruses tested, leading the researchers to believe that the results would likely be similar.

Many mouthwash and gargle products were also found to be highly effective, as several inactivated more than 99.9 percent of virus after only thirty seconds of contact.

"To measure how much virus was inactivated, the researchers placed the diluted solutions in contact with cultured human cells".

The 1 percent baby shampoo solution inactivated more than 99.9 percent of the human coronavirus after being in contact for two minutes.

The research study was headed by Craig Meyers, a professor in the school's department of microbiology and immunology and department of obstetrics and gynecology.

"Even though people can shed virus for a prolonged period of time, the studies we reviewed indicated that live virus, which may predict infectiousness, was only detected up to nine days in people who had mild symptoms", Sikka said. The results were published in the Journal of Medical Virology. All of the products are now available to consumers, many over-the-counter. "Certain professions including dentists and healthcare works are at contact risk of exposure".

Still, given the kind of positive results we're seeing in experiments like this - and given how few defences we now have against coronavirus, beyond common staples such as physical distancing, hand-washing, and wearing masks - the researchers say we should be looking at clinical trials to evaluate whether products like mouthwash can actually reduce viral load in COVID-19-positive patients, too. Clinical trials are needed to determine if these products can reduce the amount of virus COVID-positive patients or those with high-risk occupations may spread while talking, coughing or sneezing.

Future studies may include a continued investigation of products that inactive human coronaviruses and what specific ingredients in the solutions tested inactivate the virus.

"Even if the use of these solutions could reduce transmission by 50 percent, it would have a major impact".

It should be noted that Janice Milici, Samina Alam, David Quillen, David Goldenberg, and Ren Kass from the Penn State College of Medicine as well as Richard Robinson of Brigham Young University contributed to this research.

The research was supported by funds from Penn State Huck Institutes for the Life Sciences.