A group of researchers from the United Kingdom (Cardiff and Cambridge), the United States (Denver, Colorado), Spain (Barcelona), and Canada (Ottawa) has now picked up the idea we have put forward almost exactly two months ago1 for preventive throat disinfection with virucidal agents that are known to be effective against coronaviruses and safe to use in the throat.2
The authors begin their article acknowledging that “[e]merging studies increasingly demonstrate the importance of the throat and salivary glands as sites of virus replication and transmission in early COVID-19 disease.”3 They continue: “We review known mechanisms of viral lipid membrane disruption by widely available dental mouthwash components that include ethanol, chlorhexidine, cetylpyridinium chloride, hydrogen peroxide and povidone-iodine. We also assess existing formulations for their potential ability to disrupt the SARS-CoV-2 lipid envelope, based on their concentrations of these agents, and conclude that several deserve clinical evaluation. We highlight that already published research on other enveloped viruses, including coronaviruses, directly support the idea that oral rinsing should be considered as a potential way to reduce transmission of SARS-CoV-2.”
While it appears to us that the article slightly misinterprets the available evidence for temporal virus shedding patterns in COVID-19, the approach as such, the comprehensive analysis of available options as well as the detailed description of structural aspects of the viral infection process can only be very much welcomed.
Close to the end of their article, the authors state that “given the theoretical plausibility and data we have reviewed plus the readily available products and urgent need to reduce SARS-CoV-2 infection, measures could be considered and action taken to instigate clinical investigation in the population during the outbreak.”
While such clinical investigation should definitely be carried out (we have called for such in the past4), priority should clearly be given to advising people to include our proposal in their personal protective regime even before results of such research are available, given precisely (1.) the “theoretical plausibility” and (2.) what the authors say themselves immediately afterwards: “Mouthwashes [are] widely utilized in daily oral and dental hygiene for cosmetic and medical reasons and have demonstrated acceptable tolerability when used multiple times daily for durations of 6 months and longer.”
Little to no risk, high theoretical plausibility of a positive effect.
For anyone relying on logic in urgent decision making, in this case the apparent medical logic of the matter, rather than on waiting for disaster to strike, our proposal was clearly the first choice for self-protection from the outset.
We would also like to mention another call to reason, published just two weeks after our own initial article, in a letter to the editors of the British Medical Journal by a Visiting Professor at Aston University, UK – pointing to prior indications for efficacy of preventive throat disinfection -,5 that went mostly unheeded in a similar way as did our initial proposal.
It has become clear from positive examples in Italy that emphasis must be put on tackling infections as early as at all possible in order to avoid lethal outcomes. In the exemplary regime developed in Piacenza, infected people are advised on how to monitor and treat themselves at home6 rather than being (later) monitored and treated in the hospital (an optimal idea given that hospitals are known for being “optimal” environments for acquiring infections and superinfections). One procedure which is typically being carried out in a hospital ICU is regular oropharyngeal disinfection in order to avoid development of pneumonia in patients. Hence our proposal might well, somewhat flippantly, be considered as “Piacenza on steroids”.
And we cannot resist to share the experience we made on the Facebook page of “Nature”, one of the world’s two leading scientific journals. In the early days, hopeful and confident to be contributing to saving many lives and healthy lung functions, we posted a link to our article in the comment section. An editor told us he had masked our link and asked us what we were doing, telling us he could not see on the Website of the WHO any recommendation to do what we were proposing. Belief in authority: 100 %. Confidence in his own thinking and scientific logic: 0 %.
So, one might ask, why did we not pursue other routes to make our proposal more widely known? We did. Among other things, we immediately wrote to Professor Drosten of Charité Berlin, inventor of the first COVID-19 test and principal COVID-19 advisor to Mrs. Merkel. We received the same answer that highly reputed US pulmonologist Bruce L. Davidson MD, whom we had cited extensively in our article, personally told us he received from Professor Drosten: none.
The stark irony, better: illogic of the matter is that Professor Drosten just very recently admonished colleagues, doctors and professors, in the medical community for exceeding their area of competence when weighing in on COVID-19. While himself acknowledging that, being entirely focused on the virology of coronaviruses, he has limited to no clinical experience and, as we may confidently hypothesize, is therefore not as accustomed to thinking in the same systemic way about the human organism as, for example, we are. And we ask ourselves where the logic resides when he, in his most recent podcast, goes to great lengths to discuss economic implications of reopening the economy rather sooner or rather later, without any apparent pertinent expertise.
We cannot stress enough, on the other hand, that without Professor Drosten’s pioneering work in his collaborative Munich study, we would not have arrived at formulating our proposal, at least not this early.
Observing in our own local neighborhood, particularly in our local supermarket, how the officially prescribed measures against COVID-19 are being observed, we must observe that these measures cannot possibly be very effective. Except for the owner of the supermarket (who, by the way, told us he is personally doing exactly what we have proposed), all employees wear their face masks under their chins at all times (at least that we see them), apparently because it is highly uncomfortable to carry and breathe through a mask during an entire shift.
The simple and practical way to tackle COVID-19 appears, thus, to still be the old-fashioned way that “simply makes sense” (as a senior scientist with NASA has written to us privately).

- https://loico.com/the-logic-of-surviving-the-coronavirus-pandemic/[↩]
- https://www.cardiff.ac.uk/news/view/2393858-scientists-call-for-urgent-research-on-potential-for-mouthwash-to-reduce-sars-cov-2-transmission[↩]
- https://academic.oup.com/function/advance-article/doi/10.1093/function/zqaa002/5836301[↩]
- https://loico.com/additional-thoughts-regarding-benefit-throat-disinfection-covid-19-like-epidemics/[↩]
- https://www.bmj.com/content/369/bmj.m1324/rr-5[↩]
- https://www.ilgiornale.it/news/cronache/coronavirus-metodo-che-evita-strage-nessun-paziente-morto-1861189.html[↩]