Single-cell landscape revealed immune characteristics associated with disease phases in brucellosis patients.

A comprehensive immune landscape for Brucella infection is crucial for developing new treatments for brucellosis. Here, we utilized single-cell RNA sequencing (scRNA-seq) of 290,369 cells from 35 individuals, including 29 brucellosis patients from acute (n = 10), sub-acute (n = 9), and chronic (n = 10) phases as well as six healthy donors. Enzyme-linked immunosorbent assays were applied for validation within this cohort. Brucella infection caused a significant change in the composition of peripheral immune cells and inflammation was a key feature of brucellosis. Acute patients are characterized by potential cytokine storms resulting from systemic upregulation of S100A8/A9, primarily due to classical monocytes. Cytokine storm may be mediated by activating S100A8/A9-TLR4-MyD88 signaling pathway. Moreover, monocytic myeloid-derived suppressor cells were the probable contributors to immune paralysis in acute patients. Chronic patients are characterized by a dysregulated Th1 response, marked by reduced expression of IFN-γ and Th1 signatures as well as a high exhausted state. Additionally, Brucella infection can suppress apoptosis in myeloid cells (e.g., mDCs, classical monocytes), inhibit antigen presentation in professional antigen-presenting cells (APCs; e.g., mDC) and nonprofessional APCs (e.g., monocytes), and induce exhaustion in CD8+ T/NK cells, potentially resulting in the establishment of chronic infection. Overall, our study systemically deciphered the coordinated immune responses of Brucella at different phases of the infection, which facilitated a full understanding of the immunopathogenesis of brucellosis and may aid the development of new effective therapeutic strategies, especially for those with chronic infection.

Olgotrelvir as a Single-Agent Treatment of Nonhospitalized Patients with Covid-19.

BACKGROUND: Olgotrelvir is an oral antiviral with dual mechanisms of action targeting severe acute respiratory syndrome coronavirus 2 main protease (i.e., Mpro) and human cathepsin L. It has potential to serve as a single-agent treatment of coronavirus disease 2019 (Covid-19). METHODS: We conducted a phase 3, double-blind, randomized, placebo-controlled trial to evaluate the efficacy and safety of olgotrelvir in 1212 nonhospitalized adult participants with mild to moderate Covid-19, irrespective of risk factors, who were randomly assigned to receive orally either 600 mg of olgotrelvir or placebo twice daily for 5 days. The primary and key secondary end points were time to sustained recovery of a panel of 11 Covid-19-related symptoms and the viral ribonucleic acid (RNA) load. The safety end point was incidence of treatment-emergent adverse events. RESULTS: The baseline characteristics of 1212 participants were similar in the two groups. In the modified intention-to-treat population (567 patients in the placebo group and 558 in the olgotrelvir group), the median time to symptom recovery was 205 hours in the olgotrelvir group versus 264 hours in the placebo group (hazard ratio, 1.29; 95% confidence interval [CI], 1.13 to 1.46; P<0.001). The least squares mean (95% CI) changes of viral RNA load from baseline were -2.20 (-2.59 to -1.81) log10 copies/ml in olgotrelvir-treated participants and -1.40 (-1.79 to -1.01) in participants receiving placebo at day 4. Skin rash (3.3%) and nausea (1.5%) were more frequent in the olgotrelvir group than in the placebo group; there were no treatment-related serious adverse events, and no deaths were reported. CONCLUSIONS: Olgotrelvir as a single-agent treatment significantly improved symptom recovery. Adverse effects were not dose limiting. (Funded by Sorrento Therapeutics, a parent company of ACEA Therapeutics; ClinicalTrials.gov number, NCT05716425.).

Prevalence and correlates of mental health problems among different occupations of medical workers during COVID-19 outbreak in China.

Background: Health workers involved in the fight to prevent the COVID-19 outbreak were exposed to hazards. Detailed information on mental health problems in different medical occupations is crucial. To examined the prevalence of mental health issues in three medical occupations as well as the relationships between mental health problems and correlates in each occupation. Methods: This study utilizing the Questionnaire Star program was conducted among medical workers working at medical institutions in China from February 17 to 24, 2020. The Self-Reporting Questionnaire (SRQ-20), the Zung Self-rating Anxiety Scale (SAS), and the Zung Self-rating Depression Scale (SDS) were used to assess mental health problems. Results: The prevalence of any mental health problems in the three occupations was 43.6, 34.6, and 32.9% for nurses, paramedical workers (PMWs), and doctors, respectively. Three occupations shared some correlates, such as being overworked, not having enough time to rest, support from colleagues, and previous mental health status. There were specific factors for each occupation. For doctors, age, educational level, living status, support from family, and previous physical status were related factors in mental health problems. Working in a designated hospital for treating COVID-19, having COVID-19 event exposures, and receiving support from family were associated with the mental health problems of the nurses. PMWs' mental health problems was linked to educational level and care from supervisors or heads of department. Conclusion: Different medical occupations have distinct impacts on mental health issues. Policy makers and mental health professionals working to prepare for potential disease outbreaks should be aware of multiple factors in different occupations.

Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19.

BACKGROUND: Simnotrelvir is an oral 3-chymotrypsin-like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial. METHODS: In this phase 2-3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19-related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed. RESULTS: A total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, -35.8 hours [95% CI, -60.1 to -12.4]; P = 0.006 by Peto-Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], -1.51±0.14 log10 copies per milliliter; 95% CI, -1.79 to -1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate. CONCLUSIONS: Early administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.).

Persistent Urinary Tract Infection in Association with Community-Acquired NDM-5 Escherichia coli Clonal Group Following COVID-19 Infection - Beijing Municipality, China, 2023.

What is already known about this topic?: The hospital-acquired infections caused by New Delhi metallo-beta-lactamase (NDM)-producing strains are typically attributed to a single clonal lineage. What is added by this report?: In this study, we encountered a unique case of community-acquired NDM-5 Escherichia coli urinary tract infection (UTI) following coronavirus disease 2019 (COVID-19). The UTI persisted for a duration of at least 45 days. Genomic analyses revealed the presence of two NDM-5 strains, both sharing an identical chromosomal background but distinct, homologous, and recombined plasmids. This case suggests that a diverse range of resistance genes may be present within the human body, with drug-resistant strains undergoing continuous evolution during infection. The intestinal tract may have been its drug-resistant gene pool. What are the implications for public health practice?: The observations presented in this case indicate that the endogenous acquisition of drug-resistant genes may also be an issue in managing multidrug-resistant organisms (MDRO). It is possible for continuous recombination to occur within carbapenem-resistant Enterobacteriaceae (CRE) during infection. In contrast to exogenously-acquired resistance, greater attention should be placed on the endogenous factors that contribute to the development of CRE within healthcare settings.

Diagnosis, treatment, and prevention of monkeypox in children: an experts' consensus statement.

Monkeypox is a zoonotic disease. Since the first human monkeypox case was detected in 1970, it has been prevalent in some countries in central and western Africa. Since May 2022, monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide. As of September 14, 2022, there have been more than 58,200 human monkeypox cases, and there is community transmission. The cessation of smallpox vaccination in 1980, which had some cross-protection with monkeypox, resulted in a general lack of immunity to monkeypox, which caused global concern and vigilance. As of September 14, 2022, there are four monkeypox cases in China, including three in Taiwan province and one in Hong Kong city. Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications. In order to improve pediatricians' understanding of monkeypox and achieve early detection, early diagnosis, early treatment,  and early disposal, we have organized national authoritative experts in pediatric infection, respiratory, dermatology, critical care medicine, infectious diseases, and public health and others to formulate this expert consensus, on the basis of the latest "Clinical management and infection prevention and control for monkeypox" released by The World Health Organization, the "guidelines for diagnosis and treatment of monkeypox (version 2022)" issued by National Health Commission of the People's Republic of China and other relevant documents. During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis, differential diagnosis, treatment, discharge criteria, prevention, disposal process, and key points of prevention and control of suspected and confirmed cases.

Efficacy and safety of Lianhua Qingwen granule in the treatment of non-influenza viral pneumonia: a randomized, double-blind, placebo-controlled, multicenter clinical study.

Objective: To observe the effectiveness and safety of Lianhua Qingwen granule in the treatment of non-influenza viral pneumonia. Methods: This study was a multicenter, randomized, double-blind, placebo-controlled trial. Subjects who met the inclusion and exclusion criteria and were clinically diagnosed with viral pneumonia (negative for influenza virus) were randomly divided into the Lianhua Qingwen granule trial group and placebo control group. Patients in the trial group was given Lianhua Qingwen granule, 2 bags at a time, 3 times a day, and the controls were given placebo, with a treatment course of 7 days. Patients' clinical symptoms and signs, and treatment-associated adverse events were observed. Subjects should be included in the full analysis set (FAS) as long as they were all given the medication and had an effectiveness test performed after randomization. Subjects should be included in the Per Protocol Set (PPS),a subset of the total analysis set, which should contain those with strong compliance, no protocol violations, and complete baseline values for the primary indicators. Results: A total of 169 subjects were enrolled in 12 subcenters, including 151 (76 in the trial group and 75 in the control group) in the FAS and 140 (68 in the trial group and 72 in the control group) in the PPS. After 7 days of treatment, the clinical symptom relief rates were 82.98% (FAS) and 87.12% (PPS) in the trial group, and 75.11% (FAS) and 76.02% (PPS) in the control group, respectively. The clinical symptom relief rates in the trial group were significantly higher than those in the control group (p < 0.001). Significant improvements in single symptoms of cough and expectoration in the trial group were observed compared with the control group (p < 0.05). There were no statistical differences in fever, sputum color change, chest pain, muscle pain, dyspnea, chills, and thirst between the two groups (p > 0.05). Safety: There were no significant differences in body weight, vital signs, blood routine, urine routine, stool routine, and blood biochemical indicators (CK, AST, ALT, Cr, and Bun) between the two groups before and after treatment (p > 0.05). During treatment, there were no significant differences in the incidence of adverse events and serious adverse events between the two groups (p > 0.05). Conclusion: Lianhua Qingwen granules improved the clinical symptoms of patients with non-influenza virus pneumonia, especially ameliorating cough and expectoration. Lianhua Qingwen granules were associated with good safety.

Effectiveness of Lianhua Qingwen Capsule in Treatment of Asymptomatic COVID-19 Patients: A Randomized, Controlled Multicenter Trial.

Background: Asymptomatic patients are unneglected sources in propagating transmission chain due to their high viral loads. However, treatments available based on symptoms seem not applicable to asymptomatic patients. In this study, the authors want to estimate the effectiveness of Lianhua Qingwen (LH) capsule on asymptomatic coronavirus disease 2019 (COVID-19) patients. Methods: A randomized controlled trial (RCT) was performed to explore the effectiveness and safety of LH capsule in treating asymptomatic COVID-19 patients. Patients were randomized to control group (isolated observation) and treatment group (LH, 4 capsules, thrice daily) for 14 days. The primary endpoints were the rate and time of nucleic acid turning negative during the isolation observation. Results: A total of 120 participants were included in the full analysis set (60 each in the control and treatment groups). Data showed that the rate of nucleic acid turning negative during the isolation observation in the treatment group was higher than that in the control group (rate difference: 21.66%, 95% confidence interval [CI]: 4.34 to 37.27, p = 0.0142). Patients in the treatment group have a shorter time of nucleic acid turning negative (7.5 vs. 14.5 days, p = 0.018). Moreover, the rate of clinical symptoms appearance in the treatment group was lower compared with that in the control group (rate difference: -31.67, 95% CI: -46.83 to -13.82, p = 0.0005). The proportion of confirmed mild and common cases in the treatment group was also lower (35.00% vs. 66.67%, p = 0.0005). No serious adverse events were documented. Conclusions: In this study, the authors illustrated that LH capsule is beneficial to asymptomatic COVID-19 patients. Considering the lack of interventions for treating asymptomatic COVID-19 patients at this stage, LH capsule could be considered as a choice. Chinese Clinical Trial Registry: ChiCTR2100042066.

Chinese expert consensus on immunoprophylaxis of common respiratory pathogens in children (2021 edition).

Respiratory tract infections are infectious diseases involving the respiratory tract (such as the sinuses, throat, airways or lungs), which are the common respiratory disorders in children. With the development of society and the improvement of economic conditions, great progress has been made in China in the prevention of common respiratory pathogens in children. As a result, the incidence and mortality of respiratory tract infections in children have dropped sharply in the past decades. However, there is still a certain gap compared with the international leading levels, which can be partly attribute to insufficient public awareness of vaccination, uneven vaccination services of vaccinators, and so on. On the basis of comprehensive analysis of the clinical evidence of immunoprophylaxis of common respiratory pathogens among children in China and abroad, combined with the clinical situation and the experience of experts, the consensus focuses on the characteristics of transmission, clinical manifestations and immunoprophylaxis of common respiratory pathogens in children, so as to provide reference for clinical practice. This consensus document applies to all Centers for Disease Control and Prevention (CDC) staff levels engaged in the prevention and control of related pathogens, vaccinators at vaccination sites, and medical staff in pediatric, respiratory, and infectious diseases departments at all levels in medical institutions.

Efficacy and Safety of Lianhua Qingke Tablets in the Treatment of Mild and Common-Type COVID-19: A Randomized, Controlled, Multicenter Clinical Study.

BACKGROUND: Lianhua Qingke (LH) tablets is an effective traditional Chinese medicine against various viral infections, especially in relieving coughing. However, its effects on COVID-19 are unknown. METHODS: To examine the therapeutic effectiveness of LH tablets in COVID-19 patients with mild and common types, a randomized, multicenter, controlled study was carried out. COVID-19 cases were randomized to undergo routine treatment with or without LH tablets (4 tablets, three times a day) for 14 days. The primary endpoints were the rate of achieving clinical symptom resolution and the corresponding time. RESULTS: There were 144 participants in the full analysis set (72 each in the LH and control groups). The LH group participants had elevated symptom alleviation rate at 14 days compared with control cases (FAS: 98.61% vs. 84.72%, p = 0.0026). In comparison with control group participants, the LH group participants had reduced median time to clinical symptom alleviation (median: 4 vs. 7 days, p < 0.0001). Higher resolution rates of coughing (98.44% vs. 84.51%, p = 0.0045) and expectoration (100% vs. 82.35%, p = 0.0268) were observed in the LH group. Times to recovery of fever (median: 2 vs. 3 days, p = 0.0007), coughing (median: 4 vs. 7 days, p < 0.0001), and expectoration (median: 3 vs. 6 days, p < 0.0001) were also notably shorter in the LH group. Moreover, the LH group had elevated improvement rates in chest computed tomography signs (FAS: 86.11% vs. 72.22%, p = 0.0402) and clinical cure at day 28 (FAS: 83.33% vs. 68.06%, p = 0.0326). However, no differences were found in the laboratory test and viral assay. Serious adverse events were not detected. CONCLUSION: These preliminary findings indicate LH tablets may be effective in symptomatic COVID-19, especially in relieving coughing. This trial was registered in Chinese Clinical Trial Registry (ChiCTR2100042069).

Integrating Chinese and western medicine for COVID-19: A living evidence-based guideline (version 1).

BACKGROUND: The coronavirus disease 2019 (COVID-19) has turned into a pandemic and resulted in huge death tolls and burdens. Integrating Chinese and western medicine has played an important role in the fight against the COVID-19 pandemic. PURPOSE: We aimed to develop a living evidence-based guideline of integrating Chinese and western medicine for COVID-19. STUDY DESIGN: Living evidence-based guideline. METHODS: This living guideline was developed using internationally recognized and accepted guideline standards, dynamically monitoring the release of new clinical evidence, and quickly updating the linked living systematic review, evidence summary tables, and recommendations. Modified Delphi method was used to reach consensus for all recommendations. The certainty of the evidence, resources, and other factors were fully considered, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of evidence and the strength of recommendations. RESULTS: The first version of this living guidance focuses on patients who are mild or moderate COVID-19. A multidisciplinary guideline development panel was established. Ten clinical questions were identified based on the status of evidence and a face-to-face experts' consensus. Finally, nine recommendations were reached consensus, and were formulated from systematic reviews of the benefits and harms, certainty of evidence, public accessibility, policy supports, feedback on proposed recommendations from multidisciplinary experts, and consensus meetings. CONCLUSION: This guideline panel made nine recommendations, which covered five traditional Chinese medicine (TCM) prescription granules/decoction (MXXFJD, QFPD, XFBD, TJQW, and JWDY), three Chinese patent medicines (LHQW granules/capsule, JHQG granules, and LHQK granules), and one Chinese herbal injection (XBJ injection). Of them, two were strongly recommended (LHQW granules/capsule and QFPD decoction), and five were weakly recommended (MXXFJD decoction, XFBD decoction, JHQG granules, TJQW granules, and JWDY decoction) for the treatment of mild and moderate COVID-19; two were weakly recommended against (XBJ injection and LHQK granules) the treatment of mild and moderate COVID-19. The users of this living guideline are most likely to be clinicians, patients, governments, ministries, and health administrators.

Impact of immune checkpoint molecules on FoxP3+ Treg cells and related cytokines in patients with acute and chronic brucellosis.

BACKGROUND: The immunoregulatory functions of regulatory T cells (Tregs) in the development and progression of some chronic infectious diseases are mediated by immune checkpoint molecules and immunosuppressive cytokines. However, little is known about the immunosuppressive functions of Tregs in human brucellosis, which is a major burden in low-income countries. In this study, expressions of immune checkpoint molecules and Treg-related cytokines in patients with acute and chronic Brucella infection were evaluated to explore their impact at different stages of infection. METHODS: Forty patients with acute brucellosis and 19 patients with chronic brucellosis admitted to the Third People's Hospital of Linfen in Shanxi Province between August 2016 and November 2017 were enrolled. Serum and peripheral blood mononuclear cells were isolated from patients before antibiotic treatment and from 30 healthy subjects. The frequency of Tregs (CD4+ CD25+ FoxP3+ T cells) and expression of CTLA-4, GITR, and PD-1 on Treg cells were detected by flow cytometry. Levels of Treg-related cytokines, including IL-35, TGF-ß1, and IL-10, were measured by customised multiplex cytokine assays using the Luminex platform. RESULTS: The frequency of Tregs was higher in chronic patients than in healthy controls (P = 0.026) and acute patients (P = 0.042); The frequency of CTLA-4+ Tregs in chronic patients was significantly higher than that in healthy controls (P = 0.011). The frequencies of GITR+ and PD-1+ Tregs were significantly higher in acute and chronic patients than in healthy controls (P < 0.05), with no significant difference between the acute and chronic groups (all P > 0.05). Serum TGF-ß1 levels were higher in chronic patients (P = 0.029) and serum IL-10 levels were higher in acute patients (P = 0.033) than in healthy controls. We detected weak correlations between serum TGF-ß1 levels and the frequencies of Tregs (R = 0.309, P = 0.031) and CTLA-4+ Tregs (R = 0.302, P = 0.035). CONCLUSIONS: Treg cell immunity is involved in the chronicity of Brucella infection and indicates the implication of Tregs in the prognosis of brucellosis. CTLA-4 and TGF-ß1 may contribute to Tregs-mediated immunosuppression in the chronic infection stage of a Brucella infection.

Perceived Psychological Feelings Make Important Contributions to the Symptoms of Common Mental Disorders of Medical Staff During the COVID-19.

OBJECTIVE: Lack of information about mental health status among medical staff during the epidemic of COVID-19 in China is one of the major barriers to psychological interventions. This paper aims to evaluate the contributions of perceived psychological feelings to the symptoms of common mental disorders among medical staff during the epidemic of COVID-19 in China. METHOD: A large sample of medical staff based on a non-probability sampling design was collected from February 17 to 24, 2020. The symptoms of common mental disorders were screened based on self-reported instruments to evaluate psychological distress, anxious symptoms, and depressive symptoms during the past week. Perceived psychological feelings were based on self-report. Logistic regressions and elastic net regularizations were used to evaluate the independent effect of the psychological feelings controlled by hospitals and participants characteristics. RESULTS: Totally 4,677 medical staff completed the survey. The prevalence of psychological distress, anxious symptoms, and depressive symptoms were 15.9% (95% CI 14.8-16.9), 16.0% (95% CI 15.0-17.1), and 34.6% (95% CI 33.2-35.9). Feelings of having adequate personal protective equipment, receiving enough emotional supports from both family members and colleagues were significantly associated with fewer symptoms of common mental disorders, while the feelings of overloaded work and insufficient rest times contributed to more psychological problems. CONCLUSIONS: Psychological feelings make important contributions to the symptoms of common mental disorders of medical staff during the epidemic of COVID-19. Strategies of psychological aids or interventions could be developed based on these feelings.

Analysis of antibiotic usage for viral community-acquired pneumonia in adults.

The rationale for the antibiotic treatment of viral community-acquired pneumonia (CAP) in adults was analyzed to develop a clinical reference standard for this condition. Clinical data from 166 patients diagnosed with viral pneumonia across 14 hospitals in Beijing from November 2010 to December 2017 were collected. The indications for medications were evaluated, and the rationale for the use of antibiotics was analyzed. A total of 163 (98.3%) patients with viral pneumonia were treated with antibiotics. A combination of C-reactive protein (CRP) and procalcitonin (PCT) was used as markers to analyze the possible indications for antibiotic use. With threshold levels set at 0.25 µg/L for PCT and 20 mg/L for CRP, the rate of unreasonable use of antibiotics was 55.2%. By contrast, at a CRP level threshold of 60 mg/L, the rate of antibiotic misuse was 77.3%. A total of 39 of the 163 (23.9%) patients did not meet the guidelines for drug selection for viral CAP in adults. The unreasonable use of antibacterial drugs for the treatment of viral CAP in adults is a serious concern. Clinicians must reduce the unnecessary use of antibiotics.

Development and validation of a prediction model for early identification of critically ill elderly COVID-19 patients.

In this study, we established a simple and practical tool for early identification of potentially high-risk individuals among elderly COVID-19 patients. Included were 2106 laboratory-confirmed COVID-19 patients aged 60 years and above in 30 provinces of mainland China. Using discrimination (the area under the receiver-operator characteristic curve [AUC]) and calibration (Hosmer-Lemeshow goodness-of-fit test and calibration plots), a nomogram for predicting critically ill cases was developed, and its performance was examined using an internal validation cohort (444 patients) and external cohort (770 patients). The proportion of critically ill patients was 11.8% (248/2106). The most common symptoms at the onset of illness were fever (66.6%), cough (34.1%), fatigue (23.3%), and expectoration (23.6%). Older age, history of chronic obstructive pulmonary disease, fever, fatigue, shortness of breath, and lymphocyte percentage lower than 20% at admission were associated with increased risk of becoming critically ill. The AUCs for the six-variable-based nomogram were 0.77 (95% CI: 0.73-0.82), 0.73 (95% CI: 0.67-0.79), and 0.77 (95% CI: 0.71-0.83) in the development, internal validation, and external validation cohorts, respectively. This six-variable-based nomogram could potentially serve as a practical and reliable tool for early identification of elderly COVID-19 patients at high risk of becoming critically ill.