A new study is floating around the web that certain oral antiseptics and mouthwashes may have the ability to inactivate coronaviruses in humans. The results indicate that some of these products might be useful for reducing the viral load, or amount of virus, in the mouth after infection and may help to reduce the spread of SARS-CoV-2, the coronavirus that causes COVID-19.
A group of physicians and scientists at Penn State College of Medicine tested several oral and nasopharyngeal rinses in a laboratory setting for their ability to inactivate human coronaviruses, which are similar in structure to SARS-CoV-2. The products evaluated include a 1% solution of baby shampoo, a neti pot, peroxide sore-mouth cleansers, and mouthwashes.
The researchers found that several of the nasal and oral rinses had a strong ability to neutralize human coronavirus, which suggests that these products may have the potential to reduce the amount of virus spread by people who are COVID-19-positive.
The team used a test to replicate the interaction of the virus in the nasal and oral cavities with the rinses and mouthwashes. They treated solutions containing a strain of human coronavirus, which served as a readily available and genetically similar alternative for SARS-CoV-2, with the baby shampoo solutions, various peroxide antiseptic rinses and various brands of mouthwash. They allowed the solutions to interact with the virus for 30 seconds, one minute and two minutes, before diluting the solutions to prevent further virus inactivation.
To measure how much virus was inactivated, the researchers placed the diluted solutions in contact with cultured human cells. They counted how many cells remained alive after a few days of exposure to the viral solution and used that number to calculate the amount of human coronavirus that was inactivated as a result of exposure to the mouthwash or oral rinse that was tested. The results were published in the Journal of Medical Virology.
Some headlines have made it sound like swishing mouthwash can make someone who is infected less ill. That is flat out wrong. Others have made it sound like you can use mouthwash to protect yourself from catching it — like a daily vaccine. Those headlines are misleading. The claim of the study is that mouthwash will stop people who have it from passing it on as frequently.
The second thing is that the virus used in the study wasn’t COVID-19. It was a virus close to it. But, close only counts in horseshoes and hand grenades. You can only study COVID-19 in very secure labs, so the researchers used a similar — but nowhere near as dangerous — virus for their test.
It seems the team might also be skeptical of his own claims as Dr. Craig Meyers (one of the lead researchers) says, “I would say wear your mask, do your social distancing. Do what you’re suppose to be doing but this could just be an extra help.”
It could be of extra help. It’s a possibility. We’re thrilled people are researching. But, making these big promises without proof is why people are saying they have problems trusting scientists.
Mouthwash is great for oral health. It’s excellent for teeth, gums and dental hygiene. But currently there are not any products that have been proven to inactivate coronaviruses. Without more research, you should fight COVID-19 with masks, washing your hands and social distance. You should fight bad breath and bacteria with mouthwash.