In Vitro Virucidal Effects of Ultraviolet Light Prototypes on RNA viruses.

Ultraviolet-C (UVC) has been used to cause virus inactivation. The virucidal activity of three UV light lamps [UVC high frequencies (HF), UVC+B LED and UVC+A LED] was evaluated against the enveloped feline coronavirus (FCoVII), a surrogate model of SARS-CoV-2, the enveloped vesicular stomatitis virus (VSV), and the naked encephalomyocarditis virus (EMCV). Virucidal assays were performed at different time points of UV-light exposure (i.e., 5, 30 minutes and 1, 6, and 8 hours), placing each virus 180 cm below the perpendicular irradiation of the lamp and 1 and 2 meters from the perpendicular axis. We found that the UVC HF lamp had virucidal effects (≥96.8% of virus inactivation) against FCoVII, VSV and EMCV after 5 minutes of irradiation at each distance analyzed. Moreover, the UVC+B LED lamp had the highest inhibitory effects on FCoVII and VSV infectivity (≥99% of virus inactivation) when these viruses were settled below the perpendicular axis of the lamp for 5 minutes. Conversely, the UVC+A LED lamp was the least effective, achieving ≥85.9% inactivation of enveloped RNA viruses after 8 hours of UV exposure. Overall, UV light lamps, and in particular UVC HF and UVC+B LED ones, had a rapid and strong virucidal activity against distinct RNA viruses, including coronaviruses.

NRF2 Antioxidant Response and Interferon-Stimulated Genes Are Differentially Expressed in Respiratory-Syncytial-Virus- and Rhinovirus-Infected Hospitalized Children.

Respiratory diseases caused by respiratory syncytial virus (RSV) and human rhinovirus (HRV) are frequent causes of the hospitalization of children; nonetheless, RSV is responsible for the most severe and life-threatening illnesses. Viral infection triggers an inflammatory response, activating interferon (IFN)-mediated responses, including IFN-stimulated genes (ISG) expression with antiviral and immunomodulatory activities. In parallel, the reactive oxygen species (ROS) production activates nuclear factor erythroid 2-related factor 2 (NRF2), whose antioxidant activity can reduce inflammation by interacting with the NF-kB pathway and the IFN response. To clarify how the interplay of IFN and NRF2 may impact on clinical severity, we enrolled children hospitalized for bronchiolitis and pneumonia, and measured gene expression of type-I and III IFNs, of several ISGs, of NRF2 and antioxidant-related genes, i.e., glucose-6-phosphate dehydrogenase (G6PD), heme oxygenase 1 (HO1), and NAD(P)H dehydrogenase [Quinone] 1 (NQO1) in RSV- (RSV-A N = 33 and RSV-B N = 30) and HRV (N = 22)-positive respiratory samples. NRF2 and HO1 expression is significantly elevated in children with HRV infection compared to RSV (p = 0.012 and p = 0.007, respectively), whereas ISG15 and ISG56 expression is higher in RSV-infected children (p = 0.016 and p = 0.049, respectively). Children admitted to a pediatric intensive care unit (PICU) had reduced NRF2 expression (p = 0.002). These data suggest, for the first time, that lower activation of the NRF2 antioxidant response in RSV-infected infants may contribute to bronchiolitis severity.

Alterations in the Expression of IFN Lambda, IFN Gamma and Toll-like Receptors in Severe COVID-19 Patients.

Contradictory results have been reported regarding interferon (IFN) lambda (λ1-3) and IFN gamma (γ) production in COVID-19 patients. To gain insight into the roles played by these IFNs in SARS-CoV-2 infection, IFNλ1-3 and IFNγ mRNA expression was evaluated in peripheral blood mononuclear cells (PBMCs) (n = 32) and in cells of paired bronchoalveolar lavages (BALs) (n = 12). Lower IFNλ1-3 values (p < 0.001 for IFNλ1 and 3 and p = 0.013 for IFNλ2) in the PBMCs of severely ill patients were found compared to healthy donors (n = 15). Reduced levels of IFNγ were also detected in patients' PBMCs (p < 0.01) and BALs (p = 0.041) compared to healthy donors. The presence of secondary bacterial infections was associated with decreased IFNλ amounts in PBMCs (p = 0.001, p = 0.015 and p = 0.003, respectively) but increased concentrations of IFNλ3 (p = 0.022) in BALs. Patients with alterations in C-reactive protein, lactate dehydrogenase and D-dimer levels had decreased IFNλ1 and 3 (p = 0.003 and p < 0.001) and increased IFNγ (p = 0.08) in PBMCs. Analyzing Toll-like receptors (TLRs) involved in IFN production, we found that TLR3 was highly expressed (p = 0.033) in patients with bacterial superinfections, while TLR7 and 8 (p = 0.029 and p = 0.049) were reduced in BALs of deceased patients. Overall, severe COVID-19 might be characterized by dysregulation in IFNγ, IFNλ and TLR3, 7 and 8 production.

Natural Flavonoid Derivatives Have Pan-Coronavirus Antiviral Activity.

The SARS-CoV-2 protease (3CLpro) is one of the key targets for the development of efficacious drugs for COVID-19 treatment due to its essential role in the life cycle of the virus and exhibits high conservation among coronaviruses. Recent studies have shown that flavonoids, which are small natural molecules, have antiviral activity against coronaviruses (CoVs), including SARS-CoV-2. In this study, we identified the docking sites and binding affinity of several natural compounds, similar to flavonoids, and investigated their inhibitory activity towards 3CLpro enzymatic activity. The selected compounds were then tested in vitro for their cytotoxicity, for antiviral activity against SARS-CoV-2, and the replication of other coronaviruses in different cell lines. Our results showed that Baicalein (100 µg/mL) exerted strong 3CLpro activity inhibition (>90%), whereas Hispidulin and Morin displayed partial inhibition. Moreover, Baicalein, up to 25 µg/mL, hindered >50% of SARS-CoV-2 replication in Vero E6 cultures. Lastly, Baicalein displayed antiviral activity against alphacoronavirus (Feline-CoV) and betacoronavirus (Bovine-CoV and HCoV-OC43) in the cell lines. Our study confirmed the antiviral activity of Baicalein against SARS-CoV-2 and demonstrated clear evidence of its pan-coronaviral activity.

Comparison by Age of the Local Interferon Response to SARS-CoV-2 Suggests a Role for IFN-ε and -ω.

Children generally develop a mild disease after SARS-CoV-2 infection whereas older adults are at risk of developing severe COVID-19. Recent transcriptomic analysis showed pre-activated innate immunity in children, resulting in a more effective anti-SARS-CoV-2 response upon infection. To further characterize age-related differences, we studied type I and III interferon (IFN) response in SARS-CoV-2 infected and non-infected individuals of different ages. Specifically, levels of expression of type I (IFN-α, -ß, -ε and -ω), type III (IFN-λ1, -λ2 and -λ3) IFNs and of the IFN-stimulated genes, ISG15 and ISG56 were quantified in nasopharyngeal cells from diagnostic swabs. Basal transcription of type I/III IFN genes was highest among children and decreased with age. Among SARS-CoV-2-infected individuals, only IFN-ε and -ω levels were significantly higher in children and young adults whereas ISGs were overexpressed in infected adults. The occurrence of symptoms in children and the need for hospitalization in adults were associated to higher transcription of several IFN genes. Starting from a pre-activated transcription level, the expression of type I and III IFNs was not highly up-regulated in children upon SARS-CoV-2 infection; young adults activated IFNs' transcription at intermediate levels whereas older adults were characterized by higher ISGs and lower IFN-ε and -ω relative expression levels. Overall, our findings contribute to recognize components of a protective IFN response as a function of age, in the context of SARS-CoV-2 infection.

An Italian Multicenter Study on the Epidemiology of Respiratory Syncytial Virus During SARS-CoV-2 Pandemic in Hospitalized Children.

Since the beginning of 2020, a remarkably low incidence of respiratory virus hospitalizations has been reported worldwide. We prospectively evaluated 587 children, aged <12 years, admitted for respiratory tract infections from 1 September 2021 to 15 March 2022 in four Italian pediatric hospitals to assess the burden of respiratory viruses during the COVID-19 pandemic in Italy. At admission, a Clinical Respiratory Score was assigned and nasopharyngeal or nasal washing samples were collected and tested for respiratory viruses. Total admissions increased from the second half of October 2021 to the first half of December 2021 with a peak in early November 2021. The respiratory syncytial virus (RSV) incidence curve coincided with the total hospitalizations curve, occurred earlier than in the pre-pandemic years, and showed an opposite trend with respect to the incidence rate of SARS-CoV-2. Our results demonstrated an early peak in pediatric hospitalizations for RSV. SARS-CoV-2 may exhibit a competitive pressure on other respiratory viruses, most notably RSV.

The non-functional ACE2 isoform, but not the SARS-CoV-2 receptor, is induced as an interferon-stimulated gene, in SARS-CoV-2 infected adults.

The recently discovered truncated, non-functional, ACE2 transcript (dACE2), but not the full-length ACE2 (f-lACE2), is induced by IFNs in differentiated airway cells. We measured expression of both ACE2 isoforms in SARS-CoV-2 positive and negative subjects, in relation to Interferon-stimulated genes. A significant activation of dACE2 transcript was found, in SARS-CoV-2 positive adults either hospitalized or not, showing a positive correlation with ISG15; f-lACE2 expression was weakly activated and not ISG-related. We confirmed a specific activation of dACE2 transcript in nasopharyngeal cells, related to the mucosal IFN response.

An Italian Multicenter Study on the Epidemiology of Respiratory Syncytial Virus During SARS-CoV-2 Pandemic in Hospitalized Children

Since the beginning of 2020, a remarkably low incidence of respiratory virus hospitalizations has been reported worldwide. We prospectively evaluated 587 children, aged <12 years, admitted for respiratory tract infections from 1 September 2021 to 15 March 2022 in four Italian pediatric hospitals to assess the burden of respiratory viruses during the COVID-19 pandemic in Italy. At admission, a Clinical Respiratory Score was assigned and nasopharyngeal or nasal washing samples were collected and tested for respiratory viruses. Total admissions increased from the second half of October 2021 to the first half of December 2021 with a peak in early November 2021. The respiratory syncytial virus (RSV) incidence curve coincided with the total hospitalizations curve, occurred earlier than in the pre-pandemic years, and showed an opposite trend with respect to the incidence rate of SARS-CoV-2. Our results demonstrated an early peak in pediatric hospitalizations for RSV. SARS-CoV-2 may exhibit a competitive pressure on other respiratory viruses, most notably RSV.

Efficacy of antiseptic mouthrinses against SARS-CoV-2: A prospective randomized placebo-controlled pilot study.

OBJECTIVES: Coronavirus-disease-19 (COVID-19) continues to affect millions of individuals worldwide. Antiviral activity of mouthrinses remains an important research area as the oral cavity is a site of SARS-CoV-2 initial replication. The aim of this study was to assess the effectiveness of three different mouthrinses in reducing the oral/oropharyngeal SARS-CoV-2 viral load. METHODS: Adult patients, hospitalized with confirmed COVID-19 were recruited for the study. Oral/oropharyngeal baseline SARS-CoV-2 samples were collected and analyzed by Real-Time-PCR. Subsequently, patients were instructed to rinse with 1 % hydrogen peroxide (H2O2), 0.12 % chlorhexidine (CHX), 1 % povidone­iodine (PVP-I) or Sodium Chloride 0.9 % (placebo). Viral loads were measured right after (T1), and at 45 min (T2) from the rinse. RESULTS: In the PVP-I 1 % group, 5/8 (62.5 %) patients at T1, and 3/8 (37.5 %) patients at T2, SARS-CoV-2 was not detectable in the swab specimens. In the H2O2 1 % group, 2/11 (18.2 %) patients at T1, and 2/11 (18.2 %) other patients at T2 showed no SARS-CoV-2 loads. One (12.5 %) patient in the CHX 0.12 % group showed SARS-CoV-2 negativity at T2. One (9.1 %) patient at T1, and another (9.1 %) patient at T2 showed no SARS-CoV-2 loads in the placebo group. CONCLUSIONS: Oral SARS-CoV-2 loads were reduced at T1 in the PVP-I 1 % and H2O2 1 % groups. CLINICAL RELEVANCE: PVP-I 1 % was the most effective rinse especially in patients with low viral copy numbers at baseline.

Anti-IFN-α/-ω neutralizing antibodies from COVID-19 patients correlate with downregulation of IFN response and laboratory biomarkers of disease severity.

A significant number of COVID-19 patients were shown to have neutralizing antibodies (NAB) against IFN; however, NAB specificity, fluctuation over time, associations with biochemical and hematological parameters, and IFN gene expression are not well characterized. Binding antibodies (BAB) to IFN-α/-ß were screened in COVID-19 patients' serum. All BAB positive sera, and a subset of respiratory samples, were tested for NAB against IFN-α/-ß/-ω, using an antiviral bioassay. Transcript levels of IFN-α/-ß/-ω and IFN-stimulated genes (ISGs) were quantified. Anti-IFN-I BAB were found in 61 out of 360 (17%) of patients. Among BAB positive sera, 21.3% had a high NAB titer against IFN-α. A total of 69.2% of anti-IFN-α NAB sera displayed cross-reactivity to IFN-ω. Anti-IFN-I NAB persisted in all patients. NAB to IFN-α were also detected in 3 out of 17 (17.6%) of respiratory samples. Anti-IFN-I NAB were higher in males (p = 0.0017), patients admitted to the ICU (p < 0.0001), and patients with a fatal outcome (p < 0.0001). NAB were associated with higher levels of CRP, LDH, d-Dimer, and higher counts of hematological parameters. ISG-mRNAs were reduced in patients with persistently NAB titer. NAB are detected in a significant proportion of severe COVID-19. NAB positive patients presented a defective IFN response and increased levels of laboratory biomarkers of disease severity.

High frequency of neutralizing antibodies to type I Interferon in HIV-1 patients hospitalized for COVID-19.

The presence of anti-IFN neutralizing antibodies (NAB) has been reported in critically ill COVID-19 patients. We found that 87.5% (7/8) of HIV-1 patients co-infected with SARS-CoV-2 had serum anti-IFN-I NAB against IFN-α subtypes, IFN-ß and/or IFN-ω. Anti-IFN-I NAB were also detected in oropharyngeal samples. Patients with NAB were males, and those with high serum anti-IFN-α/ω NAB titer had severe illness and exhibited reduction in the expression of IFN-stimulated genes. Thus, high titer of anti-IFN-α/ω NAB may contribute to the greater severity of COVID-19 in HIV-1 infected patients.

First COVID-19 lockdown resulted in most respiratory viruses disappearing among hospitalised children, with the exception of rhinoviruses.

AIM: Emergency room admissions have decreased globally during the COVID-19 pandemic, particularly for respiratory diseases. We evaluated hospital admissions for respiratory diseases in the first year of the Italian pandemic and compared them with the corresponding period in 2016-2017. METHODS: The study was carried out at the Sapienza University in Rome, Italy, and covered 9 March to 28 February 2020-2021 and 2016-2017. We tested 85 hospitalised children who were negative for the virus that causes COVID-19 in 2020-2021 and compared them with 476 hospitalised children from 2016-2017, as we had also tested nasal washing samples for 14 respiratory viruses during that period. RESULTS: Hospitalisations for acute respiratory tract infections were 82.2% lower in 2020-2021 than 2016-2017. The respiratory syncytial virus (RSV) and several other viruses were detected less frequently during the pandemic. An extraordinary finding was that rhinoviruses remained seasonal. In 2020-2021, we detected a virus in 54.1% of the hospitalised children: rhinoviruses in 41, RSV in 4 and other viruses in 1. This was significantly lower than the 71.6% in 2016-2017: RSV in 130, rhinoviruses in 128 and other viruses in 83. CONCLUSION: Pandemic measures dramatically reduced childhood respiratory infections, particularly RSV, but were less effective at reducing rhinoviruses.

Distribution of Interferon Lambda 4 Single Nucleotide Polymorphism rs11322783 Genotypes in Patients with COVID-19.

Type III interferons (IFN-III), also known as IFN-Lambda, have a pivotal role during SARS-CoV-2 infection. IFN-Lambda response among individuals is heterogeneous and its association with COVID-19 symptoms severity needs to be further clarified. We analyzed the genotype frequencies of IFNL4 single nucleotide polymorphism (SNP) rs11322783 in patients with COVID-19 (n = 128), in comparison with a validated data set of European healthy controls (n = 14152). The IFNL4 SNP was also analyzed according to the haematological and clinical parameters of patients with COVID-19. The distributions of IFNL4 genotypes among SARS-CoV-2 positive patients [TT/TT 41.4% (n = 53), TT/ΔG 47.7% (n = 61) and ΔG/ΔG 10.9% (n = 14)] and healthy controls were comparable. Different levels of white blood cells (p = 0.036) and neutrophils (p = 0.042) were found in the IFNL4 different genotypes in patients with COVID-19; the ΔG/ΔG genotype was more represented in the groups with low white blood cells and neutrophils. There were no differences in major inflammation parameters (C-reactive protein, D-dimer, Albumin, and Lactate-dehydrogenase (LDH)] and survival rate according to the IFNL4 genotypes. In conclusion, although patients with COVID-19 did not exhibit a different distribution of the IFNL4 SNP, the ΔG/ΔG genotype was associated with a lower count of immune cell populations. These findings need to be confirmed in larger groups of patients with COVID-19 and the role of IFNL4 SNP needs to be also investigated in other respiratory viral infections.

SARS-CoV-2 Entry Genes Expression in Relation with Interferon Response in Cystic Fibrosis Patients.

The expression rate of SARS-CoV-2 entry genes, angiotensin-converting enzyme 2 (ACE2), the main viral receptor and the proteases, furin and transmembrane serine protease 2 (TMPRSS2) in cystic fibrosis (CF) individuals is poorly known. Hence, we examined their levels in upper respiratory samples of CF patients (n = 46) and healthy controls (n = 45). Moreover, we sought to understand the interplay of type I interferon (IFN-I) with ACE2, furin and TMPRSS2 by evaluating their gene expression with respect to ISG15, a well-known marker of IFN activation, in upper respiratory samples and after ex vivo IFNß exposure. Lower ACE2 levels and trends toward the reduction of furin and TMPRSS2 were found in CF patients compared with the healthy controls; decreased ACE2 amounts were also detected in CF individuals with pancreatic insufficiency and in those receiving inhaled antibiotics. Moreover, there was a strong positive correlation between ISG15 and ACE2 levels. However, after ex vivo IFNß stimulation of nasopharyngeal cells, the truncated isoform (dACE2), recently demonstrated as the IFN stimulated one with respect to the full-length isoform (flACE2), slightly augmented in cells from CF patients whereas in those from healthy donors, dACE2 levels showed variable levels of upregulation. An altered expression of SARS-COV-2 entry genes and a poor responsiveness of dACE2 to IFN-I stimulation might be crucial in the diffusion of SARS-CoV-2 infection in CF.

ACE2 expression is related to the interferon response in airway epithelial cells but is that functional for SARS-CoV-2 entry?

In vitro interferon (IFN)α treatment of primary human upper airway basal cells has been shown to drive ACE2 expression, the receptor of SARS-CoV-2. The protease furin is also involved in mediating SARS-CoV-2 and other viral infections, although its association with early IFN response has not been evaluated yet. In order to assess the in vivo relationship between ACE2 and furin expression and the IFN response in nasopharyngeal cells, we first examined ACE2 and furin levels and their correlation with the well-known marker of IFNs' activation, ISG15, in children (n = 59) and adults (n = 48), during respiratory diseases not caused by SARS-CoV-2. A strong positive correlation was found between ACE2 expression, but not of furin, and ISG15 in all patients analyzed. In addition, type I and III IFN stimulation experiments were performed to examine the IFN-mediated activation of ACE2 isoforms (full-length and truncated) and furin in epithelial cell lines. Following all the IFNs treatments, only the truncated ACE2 levels, were upregulated significantly in the A549 and Calu3 cells, in particular by type I IFNs. If confirmed in vivo following IFNs' activation, the induction of the truncated ACE2 isoform only would not enhance the risk of SARS-CoV-2 infection in the respiratory tract.

During the COVID-19 pandemic where has respiratory syncytial virus gone?

The diffusion of the SARS-CoV-2 virus and the implementation of restrictive measures led to a drastic reduction of respiratory syncytial virus (RSV) diffusion. Few RSV cases have been detected worldwide, even after the removal of the restrictions. We review the current literature and present possible explanations on why there has been a significant reduction of RSV detection during the COVID-19 pandemic. We also hypothesize what may happen when RSV begins to circulate again. The increase of an immunologically naïve population, with infants born from mothers who have not reinforced their immunity to RSV, could lead to greater RSV epidemics in the coming seasons. It is crucial to prepare the scientific community and to keep RSV surveillance active to avoid dramatic consequences.

Viral community acquired pneumonia at the emergency department: Report from the pre COVID-19 age.

The role of viruses in community acquired pneumonia (CAP) has been largely underestimated in the pre-coronavirus disease 2019 age. However, during flu seasonal early identification of viral infection in CAP is crucial to guide treatment and in-hospital management. Though recommended, the routine use of nasopharyngeal swab (NPS) to detect viral infection has been poorly scaled-up, especially in the emergency department (ED). This study sought to assess the prevalence and associated clinical outcomes of viral infections in patients with CAP during peak flu season. In this retrospective, observational study adults presenting at the ED of our hospital (Rome, Italy) with CAP from January 15th to February 22th, 2019 were enrolled. Each patient was tested on admission with Influenza rapid test and real time multiplex assay. Seventy five consecutive patients were enrolled. 30.7% (n = 23) tested positive for viral infection. Of these, 52.1% (n = 12) were H1N1/FluA. 10 patients had multiple virus co-infections. CAP with viral infection did not differ for any demographic, clinic and laboratory features by the exception of CCI and CURB-65. All intra-ED deaths and mechanical ventilations were recorded among CAP with viral infection. Testing only patients with CURB-65 score ≥2, 10 out of 12 cases of H1N1/FluA would have been detected saving up to 40% tests. Viral infection occurred in one-third of CAP during flu seasonal peak 2019. Since not otherwise distinguishable, NPS is so far the only reliable mean to identify CAP with viral infection. Testing only patients with moderate/severe CAP significantly minimize the number of tests.

KI and WU Polyomavirus in Respiratory Samples of SARS-CoV-2 Infected Patients.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been declared a global pandemic. Our goal was to determine whether co-infections with respiratory polyomaviruses, such as Karolinska Institutet polyomavirus (KIPyV) and Washington University polyomavirus (WUPyV) occur in SARS-CoV-2 infected patients. Oropharyngeal swabs from 150 individuals, 112 symptomatic COVID-19 patients and 38 healthcare workers not infected by SARS-CoV-2, were collected from March 2020 through May 2020 and tested for KIPyV and WUPyV DNA presence. Of the 112 SARS-CoV-2 positive patients, 27 (24.1%) were co-infected with KIPyV, 5 (4.5%) were positive for WUPyV, and 3 (2.7%) were infected simultaneously by KIPyV and WUPyV. Neither KIPyV nor WUPyV DNA was detected in samples of healthcare workers. Significant correlations were found in patients co-infected with SARS-CoV-2 and KIPyV (p < 0.05) and between SARS-CoV-2 cycle threshold values and KIPyV, WUPyV and KIPyV and WUPyV concurrently detected (p < 0.05). These results suggest that KIPyV and WUPyV may behave as opportunistic respiratory pathogens. Additional investigations are needed to understand the epidemiology and the prevalence of respiratory polyomavirus in COVID-19 patients and whether KIPyV and WUPyV could potentially drive viral interference or influence disease outcomes by upregulating SARS-CoV-2 replicative potential.

Differential induction of type I and III interferon genes in the upper respiratory tract of patients with coronavirus disease 2019 (COVID-19).

The natural course of type I and III interferon (IFN) response in the respiratory tract of COVID-19 patients needs to be better defined. We showed that type I/III IFNs, IFN-regulatory factor 7 (IRF7), and IFN stimulated genes (ISGs), are highly expressed in the oropharyngeal cells of SARS-CoV-2 positive patients compared to healthy controls. Notably, the subgroup of critically-ill patients that required invasive mechanical ventilation had a general decrease in expression of IFN/ISG genes. Heterogeneous patterns of IFN-I/III response in the respiratory tract of COVID-19 patients may be associated to COVID-19 severity.