Nasal povidone-iodine (PVP-I) solutions at concentrations between 0.5% and 2.5% were capable of rapidly inactivating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro at relatively short contact times, according to study results published in JAMA Otolaryngology–Head & Neck Surgery.

High viral loads of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), have been detected in both the nasopharynx and oropharynx of asymptomatic and symptomatic carriers. Physical barriers and personal protective equipment are typically employed to reduce transmission of the virus through aspiration, but some research has supported the use of intranasal PVP-I solutions as an effective agent against SARS-CoV-2.

In this in vitro laboratory study, researchers tested nasal antiseptic solutions composed of aqueous PVP-I as the active ingredient against the fully sequenced USA-WA1/2020 strain of SARS-CoV-2. Diluted concentrations of PVP-I at 0.5%, 1.25%, and 2.5% were studied, and efficacy of these solutions was compared with controls. The positive control consisted of 70% ethanol on test media infected with SARS-CoV-2. The virus-absent test media were added to 2 tubes of the compounds, which served as toxicity and neutralization controls.

Investigators incubated both the test solutions and the virus at a mean room temperature of 22 °C for 15 and 30 seconds. The log reduction value following 15 seconds and 30 seconds of the given treatment comprised the primary outcome.

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All 3 PVP-I solutions completely inactivated SARS-CoV-2 within 15 seconds of contact, as represented by a reduction of greater than 3log10 of the 50% cell culture infectious dose (CCID50) of the virus (3.67 log10 CCID50/0.1 mL to ≤0.67 log10 CCID50/0.1 mL). In contrast, the positive ethanol control did not completely inactivate the virus after this same time period. There were no cytotoxic effects observed on cells following contact with the tested nasal antiseptics.

A limitation of the study included the lack of in vivo assessment of the efficacy and safety of the PVP-I solutions against SARS-CoV-2.

Based on their findings, the investigators concluded that “povidone-iodine nasal irrigation may be beneficial for the population at large as an adjunct to mask usage as a means of virus mitigation.”

Disclosure: This clinical trial was supported by Veloce BioPharma. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Frank S, Brown SM, Capriotti JA, Westover JB, Pelletier JS, Tessema B. In vitro efficacy of a povidone-iodine nasal antiseptic for rapid inactivation of SARS-CoV-2. JAMA Otolaryngol Head Neck Surg. Published online September 17, 2020. doi:10.1001/jamaoto.2020.3053