In a prior in vitro study, Taffix® nasal spray powder formed a protective barrier limiting entry of SARS-COV-2 Hong Kong/VM20001061/2020 and preventing >99.9% of viruses from infecting Vero-E6 cells . The protective effect of Taffix® in vitro was further verified by a real-life survey conducted in Israel during September 2020, following a “superspreader” event, which found a 78% lower rate of COVID-19 cases among Taffix® users as compared to those who did not use it at all or who failed to use it as recommended .
According to the American Centers of Disease Control and Prevention (CDC)  and the United Kingdom (UK) government publication , a variant called B.1.1.7 with a large number of mutations was detected in the Fall of 2020. This variant spreads more easily and quickly than other variants. Recent data from the UK reported that this variant may be associated with an increased risk of death compared to other variant viruses . It has since been detected in many countries around the world. This variant was first detected in the US at the end of December 2020 and is now the dominant variant .
In South Africa, the B.1.351 variant emerged independently of B.1.1.7. Originally detected in early October 2020, B.1.351 shares some mutations with B.1.1.7. Cases caused by this variant were reported in the US at the end of January 2021 . As of March 2021, the B.1.1.7 variant was the most abundant virus found in clinical samples of COVID-19 patients around the world, and the B.1.351 variant was the second most abundant .
The Delta B.1.617.2 variant, dominant in the powerful 2021 surge in COVID-19 cases in India, is currently rapidly spreading across the globe, threatening to overwhelm healthcare systems and negatively impact already challenged economies. While the data are still scarce, preliminary evidence questions the effectiveness of commercial vaccines in protecting against Delta B.1.617.2 transmission and associated morbidity.
Taffix® is used worldwide as an additional layer of protection to help reduce the risk of contracting viral diseases caused by viruses whose first portal of entry to the body passes through the nasal cavity, such as influenza viruses, rhinoviruses and coronaviruses. Its efficacy against the newly emerging SARS-CoV-2 variants is therefore clinically relevant. This study showed that Taffix® effectively blocks passage of the new variants under in vitro conditions [18, 19].
The concept of nonspecific protection against upper respiratory infectious viruses was first described by Hull  et al., who emphasized the potential of creating a hostile microenvironment in the nasal cavity to inhibit upper respiratory infectious pathogens. Indeed, many upper respiratory viruses are sensitive to low pH, including rhinoviruses [21, 22], influenza viruses , respiratory syncytial virus (RSV) , and coronavirus . Hull et al. demonstrated in a randomized, double blind, placebo-controlled clinical study that irrigation of the nasal mucosa with an acidic hydrogel spray reduced the severity and duration of common cold symptoms . Sungnak et al.  found that SARS-CoV-2 entry factors are highly expressed in goblet and ciliated nasal epithelial cells, together with innate immune genes. These factors render the nose a likely coronavirus entry point.
Taffix® low-pH (pH 3.5) gel forms a protective layer within 1 minute from spray and the acidic film is maintained on the nasal tissue for about 5 hours . The protective layer mechanically prevents virus particles from reaching the nasal mucosa and creates hostile environment to pathogens due to the acidic pH. The natural pH of the human nasal mucosa is approximately 5.5-6.5 , which is a favorable environment for most viral pathogens including the SARS-COV-2 virus . Thus, a protective device acting within a lower pH range is clinically advantageous. Taffix® is non-toxic, biocompatible, and can be easily used in addition to other protective measures, such as a face mask. It may also provide protection which is easy and comfortable to apply in situations where use of a face mask is not practical, for example during dining or sports activities.