Covid-19 is an airborne disease and the predominant route of transmission is person to person through respiratory droplets or saliva, containing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), produced during exhalation while breathing, talking, singing, coughing or sneezing. A person in close proximity (within 3-6 feet) to the infected person can acquire the infection by inhaling these droplets and aerosols that remain suspended in the air. Covid-19 also spreads by touching contaminated surfaces and then touching the eyes, nose and mouth with soiled hands, though this is now a less common mode of transmission. Symptomatic patients as well as the asymptomatic or presymptomatic patients are potential carriers and can spread the SARS-CoV-2 virus to their close contacts, which has been a major challenge to efforts in containing the disease.¹ 

Viruses are always mutating. The SARS-CoV-2  is also evolving. The Omicron variant is the dominant strain globally, but several of its descendent lineages have been identified and are being monitored. One of these is the XE variant, which is a recombinant virus. It was first detected in the United Kingdom on January 19 this year by the UK Health Security Agency (UKHSA). It has also been identified in China and Thailand. The XE variant is a recombinant of the BA.1 and BA.2 sublineages of the Omicron variant of concern. According to the World Health Organization (WHO), XE is 10% more transmissible than BA.2 “stealth” variant, which is 1.5 times more transmissible than BA.1. This makes XE the most contagious strain so far. But whether XE causes more severe disease or increases hospitalizations is still uncertain. The higher transmissibility vis-à-vis BA.2 suggests that XE has the potential to become the dominant strain. Two possible cases of XE have been detected in Mumbai and Gujarat.

The high viral load in the throat at the early stage of infection when symptoms begin to manifest, point to the throat as a major site of replication and shedding of virus in Covid-19 patients.² This highlights the need for effective oral hygiene to reduce spread of the virus in the community. Gargling to wash the throat is a popular home remedy for sore throat. Gargling with an oral antiseptic such as povidone iodine (PVP-I) has been advocated as a preventive measure against coronavirus.³ 

Unlike other commonly used antiseptics such as chlorhexidine gluconate and benzalkonium chloride, PVP-I has broad-spectrum antimicrobial activity including viricidal activity against several viruses including coronaviruses. The microbicidal effect of PVP-I is rapid and persistent.⁵ What’s notable is that despite widespread use for more than six decades, it has minimal potential for resistance.⁶ In vitro studies have demonstrated the effectiveness of PVP-I against Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) coronaviruses as well as the novel coronavirus SARS-CoV-2.⁴A study which evaluated the virucidal activity of four topical and oral PVP-I products against SARS-CoV-2 found that gargling with 0.5% PVP-I for 30 seconds had ≥99.99% viricidal activity against SARS-CoV-2. ⁷ Tsai et al and Bidra et al have demonstrated rapidly viricidal activity of PVP-I gargle and mouthwash against SARS-CoV-2 as early as 15 seconds. ^8,9 

The surge of Covid-19 cases in India has raised fears of a fourth wave. We can’t let down our guard yet because the pandemic is not over yet.

People should continue to follow a Covid appropriate behavior. Masking, physical distancing, hand hygiene, avoiding crowded public places and closed poorly ventilated spaces are therefore as important as before. Gargling with an antiseptic like PVP-I is a simple, inexpensive and safe adjunct to the aforementioned nonpharmaceutical interventions. Despite the fact that PVP-I gargles may not completely eliminate the virus, gargling does lead to considerable reduction in the viral load and disease severity as well as spread of the virus in the community.⁸ Besides patients with Covid-19, all persons with suspected exposure to Covid-19 or persons traveling to areas with high Covid spread should also gargle frequently with PVP-I gargles to reduce their potential viral load. ³

References

1. Tiong V, et al. The effectiveness of various gargle formulations and salt water against SARS-CoV-2. Sci Rep. 2021;11(1):20502. 

2. O’Donnell VB, et al. Potential role of oral rinses targeting the viral lipid envelope in SARS-CoV-2 infection. Function. 2020;1(1):zqaa002. 
3. Chopra A, et al. Can povidone iodine gargle/mouthrinse inactivate SARS-CoV-2 and decrease the risk of nosocomial and community transmission during the COVID-19 pandemic? An evidence-based update. Jpn Dent Sci Rev. 2021 Nov;57:39-45. 
4. Ricardo AP Persaud. Povidone-Iodine may be the “Silver Bullet” in the Prevention and Control of Covid-19 Infection, Based on New Scientific Data. On J Otolaryngol & Rhinol. 3(1): 2020. OJOR.MS.ID.000553. 
5. Lachapelle JM, et al: Antiseptics in the era of bacterial resistance: a focus on povidone iodine. Clin Pract 2013;10:579-92. 
6. Garg P. Role of povidone-iodine gargles in COVID-19 pandemic and a ray of hope for future. J Family Med Prim Care. 2021 Oct;10(10):3941-3942.
7. Anderson DE, et al. Povidone-iodine demonstrates rapid in vitro virucidal activity against SARS-CoV-2, the virus causing COVID-19 disease. Infect Dis Ther. 2020:1-7. 
8. Tsai C, et al. Possible beneficial role of throat gargling in the coronavirus disease pandemic. Public Health. 2020;185:45-6. 
9. Bidra AS, et al. Rapid in-vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using povidone