FULL CLAIM: Corona virus before it reaches the lungs it remains in the throat for four days and at this time the person begins to cough and have throat pains. If he drinks water a lot and gargling with warm water & salt or vinegar eliminates the virus.
The claim that SARS-CoV-2, the virus that causes COVID-19, can be stopped in its tracks by gargling warm water, salt water, or vinegar went viral on Facebook in March 2020, notably through a widely shared meme, receiving hundreds of thousands to millions of interactions in total. This claim is factually inaccurate and unsupported by scientific evidence.
By the time a person begins experiencing COVID-19 symptoms, the virus has already been spreading within the body for 1 to 14 days—the virus’ incubation period. A 17 March 2020 study, which measured incubation period as the length of time between infection and the onset of a fever, states that the median incubation period is 5.1 days and that “most patients who become symptomatic do so within 11 or 12 days and the vast majority within 14 days.”[1,2]
So, the suggestion that the virus could be stopped during the first “four days” of symptoms is false because the virus is likely to have already spread to other parts of the body. In addition, any treatment that targets only a localized area of the body, such as the throat, would be ineffective in other parts of the body where the virus has taken up residence.
There is also no evidence to suggest that the virus always attacks the throat first and remains there for four days. In addition to the nose and mouth, it is also known to enter through the eyes. In this case, again, a localized treatment to the throat would be ineffective.
The onset of the different symptoms, such as the sore throat mentioned in the claim, do not necessarily occur in the same order in all people, so attempting to treat COVID-19 based only on this symptom would be ineffective. The Centers for Disease Control and Prevention (CDC) provides a very short list of only three symptoms used to diagnose COVID-19 in the absence of a diagnostic test, the scarcity of which has recently been fueled by shortages in sample collection supplies and RNA extraction kits. This list includes a dry cough, fever, and shortness of breath.
A dry cough can indeed cause a sore throat. And reputable health agencies, including the Mayo Clinic and the U.K.’s National Health Service, list gargling with saltwater as an effective home remedy for easing sore throat symptoms. The Cleveland Clinic also adds honey, baking soda, and even whiskey to this list. However, Amesh Adalja, MD, a senior scholar at Johns Hopkins Center for Health Security says that “while it is true that coronavirus can cause a sore throat and gargling with warm water may make it feel better, it has no direct effect on the virus.”
Daniel Allan, a physician at the Cleveland Clinic, further recommends against other home remedies to treat a sore throat, including apple cider vinegar, which is mentioned in the claim as “vinegar”. Some research has indeed demonstrated the antibacterial and antifungal properties of vinegar, but no studies have yet demonstrated its antiviral properties, nor its effectiveness in fighting disease when gargled.
In summary, there is no evidence to suggest that gargling warm water, salt water, or vinegar is effective against SARS-CoV-2 in infected tissues, although gargling salt water might ease symptoms of a sore throat. Furthermore, by the time symptoms appear, localized treatments would be completely ineffective because the virus will have already spread to non-targeted tissues. There is currently no vaccine or cure for COVID-19. The best methods of prevention are frequent handwashing, disinfecting surfaces, and avoiding touching your face.
AFP Fact Check refuted the claim that saline solution kills the virus that causes COVID-19 and Full Fact concluded that there was “no evidence” to support it. The New York Times also fact checked this claim, as well as a variety of other claims about speculative remedies.
Health Feedback has produced a number of other claim reviews on COVID-19. You can view them here.
- 1 – Lauer et al. (2020) The incubation period of coronavirus disease 2019 (COVID-19) from publicly reported confirmed cases: Estimation and application. Annals of Internal Medicine.
- 2 – Baum et al. (2020) COVID-19 Incubation period: An update. NEJM Journal Watch.
- 3 – Yagnik et al. (2018) Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression. Scientific Reports.