The study’s results, which were published in the Journal of Medical Virology, suggest that some of these oral-hygiene products might be useful for reducing the viral load in the mouth after infection—and perhaps limit the spread of the novel coronavirus to others.
In concluding the findings, the researchers tested a variety of oral and nasopharyngeal rinses, which included a 1-percent solution of baby shampoo, a neti pot, peroxide sore-mouth cleansers, and mouthwashes.
In order to measure how much virus was inactivated, the researchers made sure that the diluted solutions came in contact with cultured human cells. Then they counted how many cells remained alive after a few days of exposure—and that figure was used to calculate the amount of virus that was inactivated due to the tested mouthwash or oral rinse.
The researchers eventually found that several of the nasal and oral rinses showcased strong potential in neutralizing human coronaviruses, indicating that these products could be used to reduce the amount of virus spread by those who have tested positive for the coronavirus.
“While we wait for a vaccine to be developed, methods to reduce transmission are needed,” Craig Meyers, the study’s lead author and professor of microbiology and immunology and obstetrics and gynecology, said in a statement.
“The products we tested are readily available and often already part of people’s daily routines.”
The 1-percent baby shampoo solution—often used by doctors to rinse the sinuses—was able to inactivate more than 99.9 percent of human coronavirus after two minutes of contact.
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.
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.
For Meyers, the study’s results with mouthwashes and oral rinses are very promising.
“People who test positive for COVID-19 and return home to quarantine may possibly transmit the virus to those they live with,” he said.
“Certain professions, including dentists and other health-care workers, are at a constant risk of exposure. 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. Even if the use of these solutions could reduce transmission by 50 percent, it would have a major impact.”
Meyers said the next step is to expand upon these results by conducting clinical trials that can evaluate whether these over-the-counter products can effectively reduce viral loads in coronavirus-positive patients.
Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.