No Remdesivir Resistance Observed in the Phase 3 Severe and Moderate COVID-19 SIMPLE Trials.

Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in hospitalized and non-hospitalized patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 SIMPLE clinical studies evaluating RDV in hospitalized participants with severe or moderate COVID-19 disease. The severe and moderate studies enrolled participants with radiologic evidence of pneumonia and a room-air oxygen saturation of ≤94% or >94%, respectively. Virology sample collection was optional in the study protocols. Sequencing and related viral load data were obtained retrospectively from participants at a subset of study sites with local sequencing capabilities (10 of 183 sites) at timepoints with detectable viral load. Among participants with both baseline and post-baseline sequencing data treated with RDV, emergent Nsp12 substitutions were observed in 4 of 19 (21%) participants in the severe study and none of the 2 participants in the moderate study. The following 5 substitutions emerged: T76I, A526V, A554V, E665K, and C697F. The substitutions T76I, A526V, A554V, and C697F had an EC50 fold change of ≤1.5 relative to the wildtype reference using a SARS-CoV-2 subgenomic replicon system, indicating no significant change in the susceptibility to RDV. The phenotyping of E665K could not be determined due to a lack of replication. These data reveal no evidence of relevant resistance emergence and further confirm the established efficacy profile of RDV with a high resistance barrier in COVID-19 patients.

Remdesivir for COVID-19 in Hospitalized Children: A Phase 2/3 Study.

OBJECTIVES: Remdesivir decreases the risk of SARS-CoV-2 infection progressing to severe disease in adults. This study evaluated remdesivir safety and pharmacokinetics in infants and children. METHODS: This was a phase 2/3, open-label trial in children aged 28 days to 17 years hospitalized for polymerase chain reaction-confirmed SARS-CoV-2 infection. Participants received for ≤10 days once-daily intravenous remdesivir doses defined using physiologically based pharmacokinetic modeling (for ≥40 kg, 200 mg day 1, then 100 mg/day; for age ≥28 days and ≥3 to <40 kg, 5 mg/kg day 1, then 2.5 mg/kg/day). Sparse pharmacokinetic samples were analyzed using population-pharmacokinetic approaches for remdesivir and metabolites GS-704277 and GS-441524. RESULTS: Among 53 participants, at enrollment the median (Q1, Q3) number of days of COVID-19 symptoms was 5 (3, 7) and hospitalization was 1 (1, 3). Underlying conditions included obesity in 19 (37%), asthma in 11 (21%), and cardiac disorders in 11 (21%). Median duration of remdesivir treatment was 5 days (range, 1-10). Remdesivir treatment had no new apparent safety trends. Two participants discontinued treatment because of adverse events including elevated transaminases; both had elevated transaminases at baseline. Three deaths occurred during treatment (and 1 after). When compared with phase 3 adult data, estimated mean pediatric parameters (area under the concentration-time curve over 1 dosing interval, AUCτ, Cmax, and Cτ) were largely overlapping but modestly increased (remdesivir, 33%-129%; GS-704277, 37%-124%; GS-441524, 0%-60%). Recovery occurred for 62% of participants on day 10 and 83% at last assessment. CONCLUSIONS: In infants and children with COVID-19, the doses of remdesivir evaluated provided drug exposure similar to adult dosing. In this study with a small sample size, no new safety concerns were observed.

Viral Resistance Analyses From the Remdesivir Phase 3 Adaptive COVID-19 Treatment Trial-1 (ACTT-1).

BACKGROUND: Remdesivir is approved for treatment of coronavirus disease 2019 (COVID-19) in nonhospitalized and hospitalized adult and pediatric patients. Here we present severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resistance analyses from the phase 3 ACTT-1 randomized placebo-controlled trial conducted in adult participants hospitalized with COVID-19. METHODS: Swab samples were collected at baseline and longitudinally through day 29. SARS-CoV-2 genomes were sequenced using next-generation sequencing. Phenotypic analysis was conducted directly on participant virus isolates and/or using SARS-CoV-2 subgenomic replicons expressing mutations identified in the Nsp12 target gene. RESULTS: Among participants with both baseline and postbaseline sequencing data, emergent Nsp12 substitutions were observed in 12 of 31 (38.7%) and 12 of 30 (40.0%) participants in the remdesivir and placebo arms, respectively. No emergent Nsp12 substitutions in the remdesivir arm were observed in more than 1 participant. Phenotyping showed low to no change in susceptibility to remdesivir relative to wild-type Nsp12 reference for the substitutions tested: A16V (0.8-fold change in EC50), P323L + V792I (2.2-fold), C799F (2.5-fold), K59N (1.0-fold), and K59N + V792I (3.4-fold). CONCLUSIONS: The similar rate of emerging Nsp12 substitutions in the remdesivir and placebo arms and the minimal change in remdesivir susceptibility among tested substitutions support a high barrier to remdesivir resistance development in COVID-19 patients. Clinical Trials Registration. NCT04280705.

COVID-19-associated Lung Microvascular Endotheliopathy: A "From the Bench" Perspective.

Rationale: Autopsy and biomarker studies suggest that endotheliopathy contributes to coronavirus disease (COVID-19)-associated acute respiratory distress syndrome. However, the effects of COVID-19 on the lung endothelium are not well defined. We hypothesized that the lung endotheliopathy of COVID-19 is caused by circulating host factors and direct endothelial infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Objectives: We aimed to determine the effects of SARS-CoV-2 or sera from patients with COVID-19 on the permeability and inflammatory activation of lung microvascular endothelial cells. Methods: Human lung microvascular endothelial cells were treated with live SARS-CoV-2; inactivated viral particles; or sera from patients with COVID-19, patients without COVID-19, and healthy volunteers. Permeability was determined by measuring transendothelial resistance to electrical current flow, where decreased resistance signifies increased permeability. Inflammatory mediators were quantified in culture supernatants. Endothelial biomarkers were quantified in patient sera. Measurements and Main Results: Viral PCR confirmed that SARS-CoV-2 enters and replicates in endothelial cells. Live SARS-CoV-2, but not dead virus or spike protein, induces endothelial permeability and secretion of plasminogen activator inhibitor 1 and vascular endothelial growth factor. There was substantial variability in the effects of SARS-CoV-2 on endothelial cells from different donors. Sera from patients with COVID-19 induced endothelial permeability, which correlated with disease severity. Serum levels of endothelial activation and injury biomarkers were increased in patients with COVID-19 and correlated with severity of illness. Conclusions: SARS-CoV-2 infects and dysregulates endothelial cell functions. Circulating factors in patients with COVID-19 also induce endothelial cell dysfunction. Our data point to roles for both systemic factors acting on lung endothelial cells and viral infection of endothelial cells in COVID-19-associated endotheliopathy.

Remdesivir and GS-441524 Retain Antiviral Activity against Delta, Omicron, and Other Emergent SARS-CoV-2 Variants.

Genetic variation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the emergence and rapid spread of multiple variants throughout the pandemic, of which Omicron is currently the predominant variant circulating worldwide. SARS-CoV-2 variants of concern/variants of interest (VOC/VOI) have evidence of increased viral transmission, disease severity, or decreased effectiveness of vaccines and neutralizing antibodies. Remdesivir (RDV [VEKLURY]) is a nucleoside analog prodrug and the first FDA-approved antiviral treatment of COVID-19. Here, we present a comprehensive antiviral activity assessment of RDV and its parent nucleoside, GS-441524, against 10 current and former SARS-CoV-2 VOC/VOI clinical isolates by nucleoprotein enzyme-linked immunosorbent assay (ELISA) and plaque reduction assay. Delta and Omicron variants remained susceptible to RDV and GS-441524, with 50% effective concentration (EC50) values 0.30- to 0.62-fold of those observed against the ancestral WA1 isolate. All other tested variants exhibited EC50 values ranging from 0.13- to 2.3-fold of the observed EC50 values against WA1. Analysis of nearly 6 million publicly available variant isolate sequences confirmed that Nsp12, the RNA-dependent RNA polymerase (RdRp) target of RDV and GS-441524, is highly conserved across variants, with only 2 prevalent changes (P323L and G671S). Using recombinant viruses, both RDV and GS-441524 retained potency against all viruses containing frequent variant substitutions or their combination. Taken together, these results highlight the conserved nature of SARS-CoV-2 Nsp12 and provide evidence of sustained SARS-CoV-2 antiviral activity of RDV and GS-441524 across the tested variants. The observed pan-variant activity of RDV supports its continued use for the treatment of COVID-19 regardless of the SARS-CoV-2 variant.

The Type 2 Asthma Mediator IL-13 Inhibits Severe Acute Respiratory Syndrome Coronavirus 2 Infection of Bronchial Epithelium.

Asthma is associated with chronic changes in the airway epithelium, a key target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many epithelial changes, including goblet cell metaplasia, are driven by the type 2 cytokine IL-13, but the effects of IL-13 on SARS-CoV-2 infection are unknown. We found that IL-13 stimulation of differentiated human bronchial epithelial cells (HBECs) cultured at air-liquid interface reduced viral RNA recovered from SARS-CoV-2-infected cells and decreased double-stranded RNA, a marker of viral replication, to below the limit of detection in our assay. An intact mucus gel reduced SARS-CoV-2 infection of unstimulated cells, but neither a mucus gel nor SPDEF, which is required for goblet cell metaplasia, were required for the antiviral effects of IL-13. Bulk RNA sequencing revealed that IL-13 regulated 41 of 332 (12%) mRNAs encoding SARS-CoV-2-associated proteins that were detected in HBECs (>1.5-fold change; false discovery rate < 0.05). Although both IL-13 and IFN-α each inhibit SARS-CoV-2 infection, their transcriptional effects differed markedly. Single-cell RNA sequencing revealed cell type-specific differences in SARS-CoV-2-associated gene expression and IL-13 responses. Many IL-13-induced gene expression changes were seen in airway epithelium from individuals with type 2 asthma and chronic obstructive pulmonary disease. IL-13 effects on airway epithelial cells may protect individuals with type 2 asthma from COVID-19 and could lead to identification of novel strategies for reducing SARS-CoV-2 infection.

Sunburn, Sun Safety and Indoor Tanning Among Schoolchildren in Ireland.

Objectives: We present patterns of sunburn, sun safety behaviors and indoor tanning bed use in a nationally representative sample of schoolchildren aged 10-17. These behaviors were explored across gender, age, and social class groups. Methods: Within the Health Behaviour in School-aged Children (HBSC) Ireland study, 10,271 young people (aged 13.54 ± 1.92, percentage girls 53.3%) reported frequency of sun safety behaviors, sunburn, and frequency and circumstances of indoor tanning bed use. Results: Children frequently experienced sunburn (90% lifetime, 74% last year), and 3% reported never using any sun protection. Applying sunscreen and wearing sunglasses were the most commonly used sun safety measures; other ways of sun protection were less popular. Indoor tanning bed use was reported by around 5%, and a large proportion of users were not advised of any indoor tanning safety measures. Sun safety behaviors varied by age and gender, with some socio-economic differences in tanning bed use. An association was found between frequency of family holidays abroad and sunburn. Conclusion: Targeted interventions are needed to increase sun safety behaviors and eliminate tanning bed use among children in Ireland.

Factors associated with changes in consumption among smokers and alcohol drinkers during the COVID-19 'lockdown' period.

BACKGROUND: The impact of the COVID-19 public health social measures (PHSM) on health behaviours is poorly understood. We aimed to identify factors associated with changes in alcohol and tobacco consumption during the strictest period of PHSM 'lockdown'. METHODS: Logistic regression analysis was conducted using secondary data from the Central Statistics Office Social Impact Survey collected during the first lockdown in Ireland (23 April- 1 May 2020). RESULTS: Of the 1362 (33.8%) individuals that responded to the survey, 80.6% were current drinkers and 26.0% were smokers. The majority of smokers (60.9%) and drinkers (60.6%) reported no change in consumption. However, 30.5% of smokers and 22.2% of drinkers reported increased consumption. Being concerned about household stress from confinement [adjusted odds ratio (aOR) 1.9, 95% confidence interval (CI) 1.3-2.9, P = 0.002], working from home (aOR 2.1, 95 CI 1.4-3.3, P < 0.001) and urban living (aOR 2.0, 95 CI 1.5-2.9, P < 0.001) were associated with increases in alcohol consumption. Feeling very nervous (aOR 2.2, 95% CI 1.2-4.0, P = 0.009), feeling downhearted/depressed (aOR 2.4, 95% CI 1.3-4.4, P = 0.004), being concerned about someone else's health (aOR 2.0, 95% CI 1.1-3.9, P = 0.031), working from home (aOR 2.3, 95% CI 1.0-5.3, P = 0.046) and increases in alcohol consumption (aOR 3.6, 95% CI 1.7-7.7, P = 0.023) were associated with increases in tobacco consumption. CONCLUSION: A mixed picture was evident in terms of changes in consumption among current smokers and drinkers. Increased consumption was more commonly reported than reductions. Increased consumption was associated with psychological distress and socio-economic factors. Policies and services should consider a response to widening inequalities in harmful consumption.

Evidence-based protocol for prophylactic antibiotics in open fractures: improved antibiotic stewardship with no increase in infection rates.

BACKGROUND: Evidence-based guidelines for prophylactic antibiotic use in open fractures recommend short-course, narrow-spectrum antibiotics for Gustilo Grade I or II open fractures and broader gram-negative coverage for Grade III open fractures. No studies to date have assessed the impact of these guidelines on infection rates in open fractures. Infection rates before and after the new protocol implementation were examined. METHODS: A new protocol was implemented including antibiotic prophylaxis based on grade of open fracture: Grade I/II fractures, cefazolin (clindamycin if allergy); Grade III fractures, ceftriaxone (clindamycin and aztreonam if allergy) for 48 hours. Aminoglycosides, vancomycin, and penicillin were removed from the protocol. Data for 174 femur and tibia/fibula open fractures (101 preprotocol and 73 postprotocol) were analyzed. Patients who were moribund or managed at another institution for greater than 24 hours were excluded. The National Healthcare Safety Network risk index was used to provide risk adjustment. RESULTS: No significant differences in the study cohorts (preprotocol and postprotocol) were identified for demographics (age, 37.2 [14.8] years vs. 40.0 [17.9] years; male, 71.3% vs. 79.5%) or mechanism of injury (motor vehicle crash, 67.3% vs. 64.4%; other blunt, 28.7% vs. 32.9%; penetrating, 4.0% vs. 2.8%). After protocol implementation, the use of aminoglycoside and glycopeptide antibiotics was significantly reduced (53.5% vs. 16.4%, p = 0.0001). The skin and soft tissue infection rate per fracture event was 20.8% before and 24.7% after protocol implementation (p = 0.58). There was no statistically significant change after stratification for fracture grade, National Healthcare Safety Network risk index, or fracture site. The rate per fracture event of resistant gram-positive and gram-negative organisms (15.8% vs. 17.8%, p = 0.84) and methicillin-resistant Staphylococcus aureus (2.0% vs. 4.1%, p = 0.65) was not different. CONCLUSION: Implementation of an evidence-based protocol for open fracture antibiotic prophylaxis resulted in significantly decreased use of aminoglycoside and glycopeptide antibiotics with no increase in skin and soft tissue infection rates. LEVEL OF EVIDENCE: Therapeutic study, level IV.