COVID-19: Povidone-Iodine Intranasal Prophylaxis in Front-line Healthcare Personnel and Inpatients

The COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2), has been implicated in over 12 million cases and counting in the United States alone and has killed at least 1300 health care workers and >250,000 citizens. This, added to the national shortage of personal protective equipment (PPE) and the need to reuse PPE, lends to the significantly increased risk to healthcare providers. At the beginning of this trial, there were only 360,000 cases.

The highest concentration of viral particles resides within the nasopharynx. The virus is thought to spread via respiratory droplets with the potential for transmission via inhalation of droplets, contact to the nose and mouth with infected materials, and airborne transmission. Given that frontline workers are involved in high-risk procedures including intubation, bronchoscopy, proning patients (which can lead to droplet production) and in some cases are reusing PPE, finding ways to reduce viral load or viral exposure are paramount.

Povidone-iodine (PVP-I) is a broad-spectrum antiseptic with activity against bacteria, fungi, and viruses. It has been previously used in both intranasal preparations against MRSA as well as oral preparations in in-vitro studies of SARS-CoV-2, MERS-CoV, H1N1, and rotavirus with good efficacy.

Due to the known breadth of its antiviral activity and similarities in molecular structure, it can be extrapolated that PVP-I should have robust activity against SARS-CoV-2. Eggers et al found that at a concentration of 1% there was a reduction of viral activity of 99.99% in in-vitro assays. At 2 minutes, a concentration of 0.23% was enough to reduce viral loads appreciably. New data has demonstrated efficacy in-vitro of PVP-I against SARS-CoV-2 at low concentrations.

PVP-I is widely used as an antiseptic and is well-tolerated and has been shown to have little to no effect on mucociliary clearance, olfaction, or thyroid function if iodine holidays are taken, although care must be utilized in monitoring.

In this study, front line healthcare workers will be asked to complete a pre-participation survey and screened for COVID positivity. They will then be given premade PVP-I gargles and nasal sprays, as well as a calendar card to mark compliance. PVP-I nasal spray and gargle (10% diluted 1:30) will be used prior to the start of a shift, during "lunch break", and at the end of shift. First, the nasal spray will be sprayed in the nose (2 sprays each naris). For adequate coverage, the participant should be able to taste the iodine or see it in the back of the throat. This should be left in place for 30 seconds. Then, the participant will gargle the solution for 30 seconds and not have anything to eat or drink by mouth for 30 minutes. Treatment will continue for 3 weeks, or until the healthcare worker presents with COVID symptoms. Participants will then be tested for COVID positivity and asked to fill out a second questionnaire assessing study tolerability. At completion of the study, they will be asked to turn in their calendar card to assess how many applications they were able to complete.

Given the high rate of asymptomatic carriers, a second arm will also be planned for patients who have a 7+ day hospitalization or who are set to undergo a significant surgical procedure. These patients will be offered participation in the study as well and will be given the same questionnaire and undergo preoperative testing if they consent. For patients in the study group, PVIP gargle and nasal sprays will be applied preoperatively or shortly after admission and enrollment in the study for the non-operative group. The patients will then be retested in 2 weeks or as directed by the presentation of symptoms concerning for infection with SARS-CoV-2.

Community spread has been found to be the most likely implicated in infection and thus the trial is now being expanded to include community members. Thus, a THIRD arm has now been added to include community members. Prescreening questionnaires will be given. As long as the participant has had no prior history of a positive COVID-19 test, they will be considered eligible for participation. After a screening consultation, they will undergo a COVID-19 test (should be completed within 72 hours of screening). If negative, they will be eligible. Participants who are pregnant, breastfeeding, have thyroid disease or cancer, or who have an allergy to iodine/shellfish/or contrast dye can still participate but will automatically be on the control arm. Participants may opt to be on either the PVP-I arm or the control arm. They will be asked to fill out a daily questionnaire regarding their exposures and whether they were wearing a mask or if other people were wearing a mask at that time.