Could mouthwashes lessen coronavirus transmission?

As some scientists focus on potential COVID-19 vaccines, others want to existing products to slow the rate of coronavirus infection, including mouthwashes and oral rinses.

Alcohol-based hand sanitizers and wipes play a crucial part in reducing infection rates. However, other products may also have a job to play. Scientists at the Penn State College of Medicine in Hershey, PA, are considering oral rinses and mouthwashes.

In a recently available study, which appears in the Journal of Medical Virology, researchers determined that several oral and nasal solutions might lower the risk of viral transmission when used by those with a coronavirus infection.

Craig Meyers, professor of microbiology and immunology and obstetrics and gynecology, led the analysis. “While we await a vaccine to be developed, solutions to reduce transmission are needed,” Meyers says. “The products we tested are plentiful and often already part of people’s daily routines.”

To research, Meyers and his team used a human respiratory virus called HCoV-229E, which is in the same virus family as SARS-CoV-2. In a laboratory, they introduced various products to the virus to determine if they could successfully reduce viral activity.

The selected nasal products included a diluted Johnson’s Baby Shampoo nasal rinse and a CVS Health Neti Pot. The mouthwash gargling products tested were CVS Health Peroxide Sore Mouth Cleanser, 1.5% Hydrogen Peroxide solution (Cumberland Swan Inc.), Orajel Antiseptic Rinse (Church & Dwight Co. Inc.), Betadine 5% (Alcon Laboratories Inc.), Crest Pro-Health (Procter & Gamble), Listerine Antiseptic (Johnson & Johnson Consumer Inc.), Listerine Ultra (Johnson & Johnson Consumer Inc.), Equate (Walmart), and Antiseptic Mouthwash (CVS Health).

Researchers exposed the human coronaviruses to each solution in three separate tests lasting 30 seconds, 1 minute, and up to 2 minutes. While almost all of the selected products showed some degree of impact, the neti pot had no measurable effect across the tests.

The Johnson’s Baby Shampoo nasal rinse solution killed 99% of the coronaviruses within 1 minute and 99.9% within 2 minutes. Crest Pro-Health reduced the coronaviruses from 99.9% to greater than 99.99%.

The most impactful product was Listerine Antiseptic, which were able to decrease the virus by higher than 99.99% after 2 minutes. Overall, the Listerine and Listerine-like mouthwashes produced the best results.

The findings further validated similar results published in the Journal of Infectious Diseases in July 2020. In this earlier study, the authors determined that routine oral rinsing by people that have a coronavirus infection might decrease the viral load within their mouths, throat, and nose. This may potentially decrease the amount they could transmit to others with a cough or sneeze.

Additionally, the research team found it interesting that the three products with hydrogen peroxide as the key ingredient inactivated the virus at a rate between 90 and 99%. This result supports previous research that also found hydrogen peroxide answers to succeed against SARS-CoV-2.

Taken together, there will do research open to strongly suggest these products could help decrease the transmission of SARS-CoV-2 between someone with contamination and someone lacking any infection.

Meyers explains: “Individuals who test positive for COVID-19 and return home to quarantine may possibly transmit the virus to those they live with. Certain professions, including dentists and other healthcare workers, are in a constant risk of exposure.”