The Effect of Povidone-Iodine Nasal Spray on Nasopharyngeal SARS-CoV-2 Viral Load: A Randomized Control Trial.

OBJECTIVES/HYPOTHESIS: To determine the effect of povidone-iodine (PVP-I) nasal sprays on nasopharyngeal (NP) viral load as assessed by cycle threshold (Ct) on quantitative polymerase chain reaction (qPCR) of SARS-CoV-2 in outpatients. STUDY DESIGN: Three arm, triple blinded, randomized, placebo-controlled clinical trial. METHODS: Participants were randomized within 5 days of testing positive for COVID-19 to receive nasal sprays containing placebo (0.9% saline), 0.5% PVP-I, or 2.0% PVP-I. NP swabs for qPCR analysis were taken at baseline, 1-hour post-PVP-I spray (two sprays/nostril), and 3 days post-PVP-I spray (20 sprays/nostril). Symptom and adverse event questionnaires were completed at baseline, day 3, and day 5. University of Pennsylvania Smell Identification Tests (UPSIT) were completed at baseline and day 30. RESULTS: Mean Ct values increased over time in all groups, indicating declining viral loads, with no statistically significant difference noted in the rate of change between placebo and PVP-I groups. The 2.0% PVP-I group showed statistically significant improvement in all symptom categories; however, it also reported a high rate of nasal burning. Olfaction via UPSIT showed improvement by at least one category in all groups. There were no hospitalizations or mortalities within 30 days of study enrollment. CONCLUSIONS: Saline and low concentration PVP-I nasal sprays are well tolerated. Similar reductions in SARS-CoV-2 NP viral load were seen over time in all groups. All treatment groups showed improvement in olfaction over 30 days. These data suggest that dilute versions of PVP-I nasal spray are safe for topical use in the nasal cavity, but that PVP-I does not demonstrate virucidal activity in COVID-19 positive outpatients. LEVEL OF EVIDENCE: 2 Laryngoscope, 132:2089-2095, 2022.

Impact of SARS-CoV-2 vaccination in healthcare workers in a network of clinics in Latin America.

Objectives: Healthcare workers (HCWs) have been severely affected in terms of both morbidity and mortality since the beginning of the COVID-19 pandemic. During the first few months of 2021, Colombia experienced a surge in positive cases. This study aimed to evaluate the effect of vaccination on the incidence of new positive cases in HCWs. Design: This was a retrospective cohort study of frontline employees in a network of clinics in Colombia, who were prioritized for COVID-19 vaccination from February to March 2021. Results: Our findings were consistent with recent reports. During early 2020, the incidence of HCWs positively diagnosed with COVID-19 in Colombia was higher than that for the general population. With the start of the national vaccination program, the incidence among HCWs decreased from April 2021, while that for the general population remained relatively unchanged. Our study identified lower infection rates among HCWs during April (odds ratio [OR], 0.72 [95% CI 0.58-0.90]; p < 0.01) and May (odds ratio [OR], 0.25 [95% CI 0.18-0.36]; p < 0.01). Conclusions: COVID-19 vaccination rollout in Colombia during early 2021 led to a decrease in the incidence of new positive cases among HCWs, in contrast to a continuing surge in the general population. Our findings suggested that COVID-19 vaccination provided adequate immunity, which guaranteed protection to HCWs.

Determinants of SARS-CoV-2 entry and replication in airway mucosal tissue and susceptibility in smokers.

Understanding viral tropism is an essential step toward reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, decreasing mortality from coronavirus disease 2019 (COVID-19) and limiting opportunities for mutant strains to arise. Currently, little is known about the extent to which distinct tissue sites in the human head and neck region and proximal respiratory tract selectively permit SARS-CoV-2 infection and replication. In this translational study, we discover key variabilities in expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), essential SARS-CoV-2 entry factors, among the mucosal tissues of the human proximal airways. We show that SARS-CoV-2 infection is present in all examined head and neck tissues, with a notable tropism for the nasal cavity and tracheal mucosa. Finally, we uncover an association between smoking and higher SARS-CoV-2 viral infection in the human proximal airway, which may explain the increased susceptibility of smokers to developing severe COVID-19. This is at least partially explained by differences in interferon (IFN)-ß1 levels between smokers and non-smokers.

ACE2 localizes to the respiratory cilia and is not increased by ACE inhibitors or ARBs.

The coronavirus SARS-CoV-2 is the causative agent of the ongoing severe acute respiratory disease pandemic COVID-19. Tissue and cellular tropism is one key to understanding the pathogenesis of SARS-CoV-2. We investigate the expression and subcellular localization of the SARS-CoV-2 receptor, angiotensin-converting enzyme 2 (ACE2), within the upper (nasal) and lower (pulmonary) respiratory tracts of human donors using a diverse panel of banked tissues. Here, we report our discovery that the ACE2 receptor protein robustly localizes within the motile cilia of airway epithelial cells, which likely represents the initial or early subcellular site of SARS-CoV-2 viral entry during host respiratory transmission. We further determine whether ciliary ACE2 expression in the upper airway is influenced by patient demographics, clinical characteristics, comorbidities, or medication use, and show the first mechanistic evidence that the use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARBs) does not increase susceptibility to SARS-CoV-2 infection through enhancing the expression of ciliary ACE2 receptor. These findings are crucial to our understanding of the transmission of SARS-CoV-2 for prevention and control of this virulent pathogen.