Stabilization of the Dimeric State of SARS-CoV-2 Main Protease by GC376 and Nirmatrelvir.

The main protease (Mpro or 3CLpro) is an enzyme that is evolutionarily conserved among different genera of coronaviruses. As it is essential for processing and maturing viral polyproteins, Mpro has been identified as a promising target for the development of broad-spectrum drugs against coronaviruses. Like SARS-CoV and MERS-CoV, the mature and active form of SARS-CoV-2 Mpro is a dimer composed of identical subunits, each with a single active site. Individual monomers, however, have very low or no catalytic activity. As such, inhibition of Mpro can be achieved by molecules that target the substrate binding pocket to block catalytic activity or target the dimerization process. In this study, we investigated GC376, a transition-state analog inhibitor of the main protease of feline infectious peritonitis coronavirus, and Nirmatrelvir (NMV), an oral, bioavailable SARS-CoV-2 Mpro inhibitor with pan-human coronavirus antiviral activity. Our results show that both GC376 and NMV are capable of strongly binding to SARS-CoV-2 Mpro and altering the monomer-dimer equilibrium by stabilizing the dimeric state. This behavior is proposed to be related to a structured hydrogen-bond network established at the Mpro active site, where hydrogen bonds between Ser1' and Glu166/Phe140 are formed in addition to those achieved by the latter residues with GC376 or NMV.

Nelfinavir: An Old Ally in the COVID-19 Fight?

After almost three years of the pandemic, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is still spreading around the world, causing notable sanitary and social issues. New antiviral therapies are constantly under investigation. However, few options have been approved for the treatment of COVID-19. Clinical trials are currently ongoing to evaluate the efficacy of nelfinavir on mild−moderate COVID-19. This study aims to investigate the activity of this compound on SARS-CoV-2 "Variants of Concern" (VOCs), comparing its effectiveness with the approved drugs remdesivir and molnupiravir. The experiments were conducted in a biosafety level 3 facility. In this study, we used a Vero-E6-cell-based infection assay to investigate the in vitro activity of nelfinavir, molnupiravir, and remdesivir. Four strains of SARS-CoV-2 were tested: 20A.EU1, B.1.1.7, P.1, and B.1.617.2. All compounds reached micromolar/submicromolar EC50, EC90, and EC99. Furthermore, the Cmax/EC50 and Cmax/EC90 ratios were >1 for all compounds and all variants tested. Our study demonstrated that nelfinavir, as molnupiravir, and remdesivir are effective in vitro on SARS-CoV-2 variants.

Pre and Post-Monoclonal Infusion Neutralizing Activity in a Subgroup of Patients Treated in the Presence of two SARS-CoV-2 Dominant Variant of Concern (VOCs) and an Ongoing Vaccination. Overall Clinical Efficacy of Two Monoclonal Antibodies Association in Umbria.

Background and Objective: In patients with mild-to-moderate COVID-19 and at high risk of progression, casirivimab/imdevimab and bamlanivimab/etesivimab were utilized in Umbria from late April to November 2021. This period was characterized by an initial prevalence of alpha (B1.1.1.7) and its progressive substitution with the delta variant (B1.617.2). Many delta infections occurred in patients already recently vaccinated.Our study aimed to observe the clinical outcome of patients treated with mAbs associations in a subgroup in which viral isolation was obtained, the pre and post-infusion neutralizing antibody activity against their viral isolate. Methods: In this retrospective observational study, the clinical outcome before and 30 days after infusion, the baseline neutralizing activity of sera against their viral isolate, and the titers of neutralizing antibodies (NAbTs) one-hour post-infusion relative to the type of mAbs associations were evaluated. Results: Better efficacy of the mAbs combinations relative to monotherapy regarding global hospitalization (p = 0.021) and 30 days symptoms (p<0.001) were seen. Infections after vaccination mostly occurred in the absence of neutralizing antibody titers (NAbT). SARS-CoV-2 delta variants were isolated within 2-4 months from vaccinations without NAbTs, or in the presence of high specific neutralizing activity after 5-6 months. NAbTs were higher after casirivimab/imdevimab infusion (p=0.001). Conclusions: Alpha infections occurred prevalently in unvaccinated patients or after 5-6 months, while delta infections prevailed in vaccinated ones. A poor neutralizing activity in most of these patients was seen. A higher NAbT after infusion of casirivimab/imdevimab was observed.

BNT162b2 Elicited an Efficient Humoral Response Against Different Strains of SARS-CoV-2 in People Living with HIV.

BACKGROUND: Vaccines have had a fundamental impact in containing the ongoing Coronavirus Disease 2019 (COVID-19) pandemic. However, there are few efficacy data relating to frail patients, including the HIV-positive patient. OBJECTIVE: This study evaluated the Severe Acute Respiratory Syndrome Coronavirus 2 (SARSCoV- 2) serum neutralization in People Living with HIV (PLWH) compared to a cohort of healthy volunteers both vaccinated with BNT162b2. METHODS: A serum sample was then withdrawn 14-21 days after the second dose of the vaccine and a serum neutralization assay was performed on Vero E6 cells. The experiments were performed using two strains of SARS-CoV-2 as 20A.EU1 and B.1.617.2. RESULTS: PLWH on Antiretroviral Therapy (ART) showed a vaccine response comparable to the healthy subjects. No correlation between CD4 count or CD4/CD8 and neutralizing antibodies (NTAbs) has been found. No differences in NT-Abs between patients with CD4 nadir above or under 200 cells/µl have been found. In both cohorts, vaccine-elicited serum better neutralized 20A.EU1 than B.1.617.2 strain. CONCLUSION: PLWH in ART and with good immuno-virological recovery showed a vaccine response comparable to that of healthy subjects and regardless of their immunological status at HIV infection diagnosis. However, larger studies are needed to confirm our results and to evaluate the vaccine response even in patients with low CD4 counts.

Efficacy of Licensed Monoclonal Antibodies and Antiviral Agents against the SARS-CoV-2 Omicron Sublineages BA.1 and BA.2

Newly emerging SARS-CoV-2 variants may escape monoclonal antibodies (mAbs) and antiviral drugs. By using live virus assays, we assessed the ex vivo inhibition of the B.1 wild-type (WT), delta and omicron BA.1 and BA.2 lineages by post-infusion sera from 40 individuals treated with bamlanivimab/etesevimab (BAM/ETE), casirivimab/imdevimab (CAS/IMD), and sotrovimab (SOT) as well as the activity of remdesivir, nirmatrelvir and molnupiravir. mAbs and drug activity were defined as the serum dilution (ID50) and drug concentration (IC50), respectively, showing 50% protection of virus-induced cytopathic effect. All pre-infusion sera were negative for SARS-CoV-2 neutralizing activity. BAM/ETE, CAS/IMD, and SOT showed activity against the WT (ID50 6295 (4355–8075) for BAM/ETE;18,214 (16,248–21,365) for CAS/IMD;and 456 (265–592) for SOT) and the delta (14,780 (ID50 10,905–21,020) for BAM/ETE;63,937 (47,211–79,971) for CAS/IMD;and 1103 (843–1334) for SOT). Notably, only SOT was active against BA.1 (ID50 200 (37–233)), whereas BA.2 was neutralized by CAS/IMD (ID50 174 (134–209) ID50) and SOT (ID50 20 (9–31) ID50), but not by BAM/ETE. No significant inter-variant IC50 differences were observed for molnupiravir (1.5 ± 0.1/1.5 ± 0.7/1.0 ± 0.5/0.8 ± 0.01 μM for WT/delta/BA.1/BA.2, respectively), nirmatrelvir (0.05 ± 0.02/0.06 ± 0.01/0.04 ± 0.02/0.04 ± 0.01 μM) or remdesivir (0.08 ± 0.04/0.11 ± 0.08/0.05 ± 0.04/0.08 ± 0.01 μM). Continued evolution of SARS-CoV-2 requires updating the mAbs arsenal, although antivirals have so far remained unaffected.

Superinfections caused by carbapenem-resistant Enterobacterales in hospitalized patients with COVID-19: a multicentre observational study from Italy (CREVID Study).

Objectives: To describe clinical characteristics and outcomes of COVID-19 patients who developed secondary infections due to carbapenem-resistant Enterobacterales (CRE). Methods: Retrospective observational study including COVID-19 patients admitted to 12 Italian hospitals from March to December 2020 who developed a superinfection by CRE. Superinfection was defined as the occurrence of documented bacterial infection >48 h from admission. Patients with polymicrobial infections were excluded. Demographic, clinical characteristics and outcome were collected. Isolates were classified as KPC, metallo-ß-lactamase (MBL) and OXA-48-producing CRE. A Cox regression analysis was performed to identify factors independently associated with 30 day mortality. Results: Overall, 123 patients (median age 66 years, IQR 59-75) were included. The majority of infections occurred in the ICU (81, 65.9%), while 42 (34.1%) in medical wards. The most common types of infection were bloodstream infections (BSI) (n = 64, 52%), followed by urinary-tract infections (UTI) (n = 28, 22.8%), hospital-acquired/ventilator-associated pneumonia (HAP/VAP) (n = 28, 22.8%), intra-abdominal infections (n = 2, 1.6%) and skin infections (n = 1, 0.8%). Sixty-three (51.2%) infections were caused by KPC-, 54 (43.9%) by MBL-, and 6 (4.8%) by OXA-48-producing CRE. Thirty-day mortality was 33.3% (41/123). On Cox regression analysis, HAP/VAP compared with UTI (HR 7.23, 95% CI 2.09-24.97, P = 0.004), BSI compared with UTI (HR 3.96, 95% CI, 1.33-11.77, P = 0.004), lymphopenia on admission (HR 3, 95% CI 1.44-6.26, P = 0.003) and age (HR 1.05, 95% CI 1.02-1.08, P = 0.002) were predictors of 30 day mortality. Conclusions: Superinfections by CRE were associated with high risk of 30 day mortality in patients with COVID-19. HAP/VAP was the strongest predictor of death in these patients.

The Combination of Molnupiravir with Nirmatrelvir or GC376 Has a Synergic Role in the Inhibition of SARS-CoV-2 Replication In Vitro.

INTRODUCTION: The development of effective vaccines has partially mitigated the trend of the SARS-CoV-2 pandemic; however, the need for orally administered antiviral drugs persists. This study aims to investigate the activity of molnupiravir in combination with nirmatrelvir or GC376 on SARS-CoV-2 to verify the synergistic effect. METHODS: The SARS-CoV-2 strains 20A.EU, BA.1 and BA.2 were used to infect Vero E6 in presence of antiviral compounds alone or in combinations using five two-fold serial dilution of compound concentrations ≤EC90. After 48 and 72 h post-infection, viability was performed using MTT reduction assay. Supernatants were collected for plaque-assay titration. All experiments were performed in triplicate, each being repeated at least three times. The synergistic score was calculated using Synergy Finder version 2. RESULTS: All compounds reached micromolar EC90. Molnupiravir and GC376 showed a synergistic activity at 48 h with an HSA score of 19.33 (p < 0.0001) and an additive activity at 72 h with an HSA score of 8.61 (p < 0.0001). Molnupiravir and nirmatrelvir showed a synergistic activity both at 48 h and 72 h with an HSA score of 14.2 (p = 0.01) and 13.08 (p < 0.0001), respectively. CONCLUSION: Molnupiravir associated with one of the two protease-inhibitors nirmatrelvir and GC376 showed good additive-synergic activity in vitro.

Efficacy of Licensed Monoclonal Antibodies and Antiviral Agents against the SARS-CoV-2 Omicron Sublineages BA.1 and BA.2.

Newly emerging SARS-CoV-2 variants may escape monoclonal antibodies (mAbs) and antiviral drugs. By using live virus assays, we assessed the ex vivo inhibition of the B.1 wild-type (WT), delta and omicron BA.1 and BA.2 lineages by post-infusion sera from 40 individuals treated with bamlanivimab/etesevimab (BAM/ETE), casirivimab/imdevimab (CAS/IMD), and sotrovimab (SOT) as well as the activity of remdesivir, nirmatrelvir and molnupiravir. mAbs and drug activity were defined as the serum dilution (ID50) and drug concentration (IC50), respectively, showing 50% protection of virus-induced cytopathic effect. All pre-infusion sera were negative for SARS-CoV-2 neutralizing activity. BAM/ETE, CAS/IMD, and SOT showed activity against the WT (ID50 6295 (4355-8075) for BAM/ETE; 18,214 (16,248-21,365) for CAS/IMD; and 456 (265-592) for SOT) and the delta (14,780 (ID50 10,905-21,020) for BAM/ETE; 63,937 (47,211-79,971) for CAS/IMD; and 1103 (843-1334) for SOT). Notably, only SOT was active against BA.1 (ID50 200 (37-233)), whereas BA.2 was neutralized by CAS/IMD (ID50 174 (134-209) ID50) and SOT (ID50 20 (9-31) ID50), but not by BAM/ETE. No significant inter-variant IC50 differences were observed for molnupiravir (1.5 ± 0.1/1.5 ± 0.7/1.0 ± 0.5/0.8 ± 0.01 µM for WT/delta/BA.1/BA.2, respectively), nirmatrelvir (0.05 ± 0.02/0.06 ± 0.01/0.04 ± 0.02/0.04 ± 0.01 µM) or remdesivir (0.08 ± 0.04/0.11 ± 0.08/0.05 ± 0.04/0.08 ± 0.01 µM). Continued evolution of SARS-CoV-2 requires updating the mAbs arsenal, although antivirals have so far remained unaffected.

Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19.

Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage.

Phylogeography and genomic epidemiology of SARS-CoV-2 in Italy and Europe with newly characterized Italian genomes between February-June 2020.

The aims of this study were to characterize new SARS-CoV-2 genomes sampled all over Italy and to reconstruct the origin and the evolutionary dynamics in Italy and Europe between February and June 2020. The cluster analysis showed only small clusters including < 80 Italian isolates, while most of the Italian strains were intermixed in the whole tree. Pure Italian clusters were observed mainly after the lockdown and distancing measures were adopted. Lineage B and B.1 spread between late January and early February 2020, from China to Veneto and Lombardy, respectively. Lineage B.1.1 (20B) most probably evolved within Italy and spread from central to south Italian regions, and to European countries. The lineage B.1.1.1 (20D) developed most probably in other European countries entering Italy only in the second half of March and remained localized in Piedmont until June 2020. In conclusion, within the limitations of phylogeographical reconstruction, the estimated ancestral scenario suggests an important role of China and Italy in the widespread diffusion of the D614G variant in Europe in the early phase of the pandemic and more dispersed exchanges involving several European countries from the second half of March 2020.

Low Brachial Artery Flow-Mediated Dilation Predicts Worse Prognosis in Hospitalized Patients with COVID-19.

BACKGROUND: Endothelial injury can be induced by coronavirus disease 2019 (COVID-19) and seems to exert a crucial pathogenic role in its most severe clinical manifestations. We aimed to investigate the association between brachial artery flow-mediated dilation (bFMD), a potential clinical and non-invasive measure of endothelial function, and in-hospital prognosis of COVID-19 patients. METHODS: Brachial artery flow-mediated dilation was assessed in hospitalized COVID-19 patients within 48 h of hospital admission. The association between bFMD and either intensive care unit (ICU) admission or in-hospital death was explored using univariable and multivariable analyses. RESULTS: Four hundred and eight patients were enrolled. Significantly lower bFMD values emerged in COVID-19 patients with either radiographic signs of pneumonia, respiratory distress, or the need for non-invasive ventilation compared with patients without these signs (p < 0.001, p = 0.001, and p < 0.001, respectively). Forty-two (10%) patients were admitted to the ICU, 76 (19%) patients died, and 118 (29%) patients met the composite endpoint of ICU admission/in-hospital death. At unadjusted Cox regression analysis showed that low bFMD (<4.4%, the median value) was associated with a higher risk for the composite endpoint of ICU admission/in-hospital death compared with high bFMD (≥4.4%, the median value) (HR 1.675, 95% CI 1.155-2.428, p = 0.007). Multi-adjusted Cox regression analyses showed that low bFMD was independently associated with a 1.519- to 1.658-fold increased risk for the composite endpoint of ICU admission/in-hospital death. CONCLUSIONS: Low bFMD predicts an unfavorable in-hospital prognosis in COVID-19 patients. The measurement of bFMD may be clinically useful in the prognostic stratification of COVID-19 patients upon hospital admission.

Early Treatment with Bamlanivimab Alone does not Prevent COVID-19 Hospitalization and Its Post-Acute Sequelae. A Real Experience in Umbria, Italy.

BACKGROUND AND OBJECTIVE: The use of monoclonal antibodies to the SARS-Cov-2 spike protein for early treatment of COVID-19 disease is being evaluated, with only phase 2 studies available to date. The emergency authorization of bamlanivimab monotherapy was obtained in November 2020 by the FDA and in March 2021 by Italian agency AIFA. Its use was then revoked in April 2021 by both. This study reports the results of bamlanivimab utilization in monotherapy in Umbria (Italian region) to verify whether, in a population with multiple risk factors, comparable results to the phase 2 BLAZE1 trial had been obtained. METHODS: Between March and April 2021, a retrospective observational study was performed on patients treated with bamlanivimab. Demographic and clinical characteristics before and after infusion were evaluated. Moreover, a telephone interview was conducted about 30 days after the infusion to evaluate the overall course. RESULTS: All patients had an early infection (mean 4±1.73 days), almost all by alpha variant (97%). No adverse events to treatment were observed. Altogether within 30 days, the hospitalization rate was 20%, 15% for COVID-19 related pathologies, versus 4% at 11 days in the BLAZE1 phase 2 study. In addition, worsening of some symptoms observed at baseline such as asthenia (77 vs. 51.3%), shortness of breath (38 vs. 23%) was registered, as well as the onset of non-restorative sleep (41%). CONCLUSION: The clinical outcome after bamlanivimab monotherapy was far below the expectation despite the patients had been infected by a theoretically sensitive viral variant.

Role of Nucleocapsid Protein Antigen Detection for Safe End of Isolation of SARS-CoV-2 Infected Patients with Long Persistence of Viral RNA in Respiratory Samples.

BACKGROUND: In SARS-CoV-2 infection, viral RNA may persist in respiratory samples for several weeks after the resolution of symptoms. Criteria to assess the end of infectivity are not unequivocally defined. In some countries, time from diagnosis is the unique criterion used, in addition to symptom cessation. This study evaluates the role of the Lumipulse® Antigen Assay (LAA) for the safe end of isolation of patients ≥21 days after the diagnosis of infection. METHODS: A total of 671 nasopharyngeal swabs from patients diagnosed with infection at least 21 days before were assessed by RT-PCR and LAA, and the role of LAA in predicting the absence of infectivity was evaluated by virus cell culture. RESULTS: Viable virus was present in 10/138 cultured samples. Eight out of ten infective patients suffered from a concomitant disease, predisposing them to long-term shedding of infective virus. In particular, infectious virus was isolated from 10/20 RT-PCR+/LAA+ cultured samples, whereas no viable virus was found in all 118 RT-PCR+/LAA- cultured swabs. LLA and RT-PCR agreed in 484/671 (72.1%) samples, with 100% and 26.7% concordance in RT-PCR negative and positive samples, respectively. CONCLUSIONS: Viable virus can be found ≥21 days after diagnosis in immunocompromised or severely ill patients. LAA better than RT-PCR predicts non-infectivity of patients and can be safely used to end isolation in cases with long persistence of viral RNA in the respiratory tract.

Circulating SARS-CoV-2 variants in Italy, October 2020-March 2021.

A growing number of emerging SARS-CoV-2 variants is being identified worldwide, potentially impacting the effectiveness of current vaccines. We report the data obtained in several Italian regions involved in the SARS-CoV-2 variant monitoring from the beginning of the epidemic and spanning the period from October 2020 to March 2021.

Cross-neutralization of SARS-CoV-2 B.1.1.7 and P.1 variants in vaccinated, convalescent and P.1 infected.

OBJECTIVES: The emergence of new variants of concern (VOCs) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) around the world significantly complicated the exit from Coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to evaluate the serum neutralizing activity of three cohorts. METHODS: BNT162b2-elicited serum (N = 103), candidates as hyper-immune plasma donors (N = 90) and patients infected with the SARS-CoV-2 P1 variant (N = 22) were enrolled. Three strains of SARS-CoV-2 have been tested: 20A.EU1, B.1.1.7 (alpha) and P.1 (gamma). Neutralizing antibodies (NT-Abs) titers against SARS-CoV-2 were evaluated. RESULTS: B.1.1.7 and P.1 are less efficiently neutralized by convalescent wild-type infected serums if compared to 20A.EU1 strain (mean titer 1.6 and 6.7-fold lower respectively). BNT162b2 vaccine-elicited human sera show an equivalent neutralization potency on the B.1.1.7 but it is significantly lower for the P.1 variant (mean titer 3.3-fold lower). Convalescent P.1 patients are less protected from other SARS-CoV-2 strains with an important reduction of neutralizing antibodies against 20A.EU1 and B.1.1.7, about 12.2 and 10.9-fold, respectively. CONCLUSIONS: BNT162b2 vaccine confers immunity against all the tested VOCs, while previous SARS-CoV-2 infection may be less protective.

SARS-CoV2 infection impairs the metabolism and redox function of cellular glutathione.

Viral infections sustain their replication cycle promoting a pro-oxidant environment in the host cell. In this context, specific alterations of the levels and homeostatic function of the tripeptide glutathione have been reported to play a causal role in the pro-oxidant and cytopathic effects (CPE) of the virus. In this study, these aspects were investigated for the first time in SARS-CoV2-infected Vero E6 cells, a reliable and well-characterized in vitro model of this infection. SARS-CoV2 markedly decreased the levels of cellular thiols, essentially lowering the reduced form of glutathione (GSH). Such an important defect occurred early in the CPE process (in the first 24 hpi). Thiol analysis in N-acetyl-Cys (NAC)-treated cells and membrane transporter expression data demonstrated that both a lowered uptake of the GSH biosynthesis precursor Cys and an increased efflux of cellular thiols, could play a role in this context. Increased levels of oxidized glutathione (GSSG) and protein glutathionylation were also observed along with upregulation of the ER stress marker PERK. The antiviral drugs Remdesivir (Rem) and Nelfinavir (Nel) influenced these changes at different levels, essentially confirming the importance or blocking viral replication to prevent GSH depletion in the host cell. Accordingly, Nel, the most potent antiviral in our in vitro study, produced a timely activation of Nrf2 transcription factor and a GSH enhancing response that synergized with NAC to restore GSH levels in the infected cells. Despite poor in vitro antiviral potency and GSH enhancing function, Rem treatment was found to prevent the SARS-CoV2-induced glutathionylation of cellular proteins. In conclusion, SARS-CoV2 infection impairs the metabolism of cellular glutathione. NAC and the antiviral Nel can prevent such defect in vitro.

National Early Warning Score 2 (NEWS2) better predicts critical Coronavirus Disease 2019 (COVID-19) illness than COVID-GRAM, a multi-centre study.

PURPOSE: Clinical scores to rapidly assess the severity illness of Coronavirus Disease 2019 (COVID-19) could be considered of help for clinicians. Recently, a specific score (named COVID-GRAM) for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, based on a nationwide Chinese cohort, has been proposed. We routinely applied the National Early Warning Score 2 (NEWS2) to predict critical COVID-19. Aim of this study is to compare NEWS2 and COVID-GRAM score. METHODS: We retrospectively analysed data of 121 COVID-19 patients admitted in two Clinics of Infectious Diseases in the Umbria region, Italy. The primary outcome was critical COVID-19 illness defined as admission to the intensive care unit, invasive ventilation, or death. Accuracy of the scores was evaluated with the area under the receiver-operating characteristic curve (AUROC). Differences between scores were confirmed used Hanley-McNeil test. RESULTS: The NEWS2 AUROC curve measured 0.87 (standard error, SE 0.03; 95% CI 0.80-0.93; p < 0.0001). The COVID-GRAM score AUROC curve measured 0.77 (SE 0.04; 95% CI 0.68-0.85; p < 0.0001). Hanley-McNeil test showed that NEWS2 better predicted severe COVID-19 (Z = 2.03). CONCLUSIONS: The NEWS2 showed superior accuracy to COVID-GRAM score for prediction of critical COVID-19 illness.