Integrated longitudinal multiomics study identifies immune programs associated with acute COVID-19 severity and mortality.

BACKGROUNDPatients hospitalized for COVID-19 exhibit diverse clinical outcomes, with outcomes for some individuals diverging over time even though their initial disease severity appears similar to that of other patients. A systematic evaluation of molecular and cellular profiles over the full disease course can link immune programs and their coordination with progression heterogeneity.METHODSWe performed deep immunophenotyping and conducted longitudinal multiomics modeling, integrating 10 assays for 1,152 Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study participants and identifying several immune cascades that were significant drivers of differential clinical outcomes.RESULTSIncreasing disease severity was driven by a temporal pattern that began with the early upregulation of immunosuppressive metabolites and then elevated levels of inflammatory cytokines, signatures of coagulation, formation of neutrophil extracellular traps, and T cell functional dysregulation. A second immune cascade, predictive of 28-day mortality among critically ill patients, was characterized by reduced total plasma Igs and B cells and dysregulated IFN responsiveness. We demonstrated that the balance disruption between IFN-stimulated genes and IFN inhibitors is a crucial biomarker of COVID-19 mortality, potentially contributing to failure of viral clearance in patients with fatal illness.CONCLUSIONOur longitudinal multiomics profiling study revealed temporal coordination across diverse omics that potentially explain the disease progression, providing insights that can inform the targeted development of therapies for patients hospitalized with COVID-19, especially those who are critically ill.TRIAL REGISTRATIONClinicalTrials.gov NCT04378777.FUNDINGNIH (5R01AI135803-03, 5U19AI118608-04, 5U19AI128910-04, 4U19AI090023-11, 4U19AI118610-06, R01AI145835-01A1S1, 5U19AI062629-17, 5U19AI057229-17, 5U19AI125357-05, 5U19AI128913-03, 3U19AI077439-13, 5U54AI142766-03, 5R01AI104870-07, 3U19AI089992-09, 3U19AI128913-03, and 5T32DA018926-18); NIAID, NIH (3U19AI1289130, U19AI128913-04S1, and R01AI122220); and National Science Foundation (DMS2310836).

Increased Pediatric Respiratory Syncytial Virus Case Counts Following the Emergence of Severe Acute Respiratory Syndrome Coronavirus 2 Can Be Attributed to Changes in Testing.

BACKGROUND: Respiratory syncytial virus (RSV) circulation dropped markedly early in the COVID-19 pandemic, followed by a resurgence with heightened case counts. The "immunity debt" hypothesis proposes that the RSV-naїve pediatric population increased during the period of low transmission. However, the evidence supporting this hypothesis is limited, and the role of changing testing practices in the perceived surge has not been comprehensively evaluated. METHODS: We conducted a multicenter, retrospective analysis of 342 530 RSV encounters and 980 546 RSV diagnostic tests occurring at 32 US pediatric hospitals in 2013-2023. We used interrupted time series analysis to estimate pandemic-associated changes in RSV patient and test volume and to quantify changes in the proportions of patients requiring hospitalization, intensive care, or mechanical ventilation. We quantified the fraction of the shifts in case counts and in the age of diagnosed patients attributable to changes in testing. RESULTS: RSV patient volume increased 2.4-fold (95% confidence interval [CI]: 1.7, 3.5) in 2021-2023 relative to the pre-pandemic phase and was accompanied by an 18.9-fold increase (95% CI: 15.0, 23.9) in RSV test volume. Shifts in patient volume and in patient age were largely attributable to increased testing. The proportions of patients with RSV that required hospitalization, intensive care, or mechanical ventilation declined significantly across all patient age groups. CONCLUSIONS: A surge in RSV testing, rather than in viral circulation, likely underlies the increased case counts observed in 2021-2023. These findings warrant a critical assessment of the immunity debt hypothesis and highlight the importance of considering the testing denominator when surveillance strategies are dynamic.

Host-microbe multiomic profiling reveals age-dependent immune dysregulation associated with COVID-19 immunopathology.

Age is a major risk factor for severe coronavirus disease 2019 (COVID-19), yet the mechanisms behind this relationship have remained incompletely understood. To address this, we evaluated the impact of aging on host immune response in the blood and the upper airway, as well as the nasal microbiome in a prospective, multicenter cohort of 1031 vaccine-naïve patients hospitalized for COVID-19 between 18 and 96 years old. We performed mass cytometry, serum protein profiling, anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays, and blood and nasal transcriptomics. We found that older age correlated with increased SARS-CoV-2 viral abundance upon hospital admission, delayed viral clearance, and increased type I interferon gene expression in both the blood and upper airway. We also observed age-dependent up-regulation of innate immune signaling pathways and down-regulation of adaptive immune signaling pathways. Older adults had lower naïve T and B cell populations and higher monocyte populations. Over time, older adults demonstrated a sustained induction of pro-inflammatory genes and serum chemokines compared with younger individuals, suggesting an age-dependent impairment in inflammation resolution. Transcriptional and protein biomarkers of disease severity differed with age, with the oldest adults exhibiting greater expression of pro-inflammatory genes and proteins in severe disease. Together, our study finds that aging is associated with impaired viral clearance, dysregulated immune signaling, and persistent and potentially pathologic activation of pro-inflammatory genes and proteins.

Increased pediatric RSV case counts following the emergence of SARS-CoV-2 are attributable to increased testing.

Background: The incidence of respiratory syncytial virus (RSV) dropped markedly early in the COVID-19 pandemic, followed by a resurgence with heightened case counts. The "immunity debt" hypothesis proposes that the RSV-naive pediatric population increased during the period of low transmission, resulting in a subsequent increased risk of infection. However, the evidence supporting this hypothesis is limited, and no studies have comprehensively evaluated the role of changing respiratory viral testing practices in the perceived surge. Methods: We conducted a multicenter, retrospective analysis of 342,530 RSV encounters and 980,546 RSV diagnostic tests occurring at 32 United States pediatric hospitals between 2013 and 2023. We used interrupted time series analysis to estimate pandemic-associated changes in RSV patient and testing volume, and to quantify changes in the proportions of patients admitted from the emergency department (ED), admitted to the intensive care unit (ICU), and receiving mechanical ventilation. We quantified the fraction of the observed shifts in case counts and in the age of diagnosed patients attributable to changes in RSV testing practices. Finally, we analyzed 524,404 influenza virus encounters and 1,768,526 influenza diagnostic tests to address the specificity of the findings to RSV. Findings: RSV patient volume increased 2.4-fold (95% CI: 1.7, 3.5) in 2021-2023 relative to the pre-pandemic phase, and was accompanied by an 18.9-fold increase (95% CI: 15.0, 23.9) in RSV test volume. Over two-thirds of the apparent shifts in patient volume and in patient age were attributable to increased testing, which was concentrated among older pediatric patients. The proportions of patients with RSV requiring hospitalization, intensive care, or mechanical ventilation declined significantly across all patient age groups. These declines were not observed for patients with influenza virus. Interpretation: A surge in RSV testing, rather than in viral circulation, likely underlies the increased case counts observed in 2021-2023. We identify expected consequences of increased testing, including the diagnosis of less severe cases and a shift in the patient age distribution. These findings warrant a critical assessment of the immunity debt hypothesis, while highlighting the importance of considering the testing denominator when surveillance strategies are dynamic. Funding: National Institutes of Health & Howard Hughes Medical Institute.

Host-Microbe Multiomic Profiling Reveals Age-Dependent COVID-19 Immunopathology.

Age is a major risk factor for severe coronavirus disease-2019 (COVID-19), yet the mechanisms responsible for this relationship have remained incompletely understood. To address this, we evaluated the impact of aging on host and viral dynamics in a prospective, multicenter cohort of 1,031 patients hospitalized for COVID-19, ranging from 18 to 96 years of age. We performed blood transcriptomics and nasal metatranscriptomics, and measured peripheral blood immune cell populations, inflammatory protein expression, anti-SARS-CoV-2 antibodies, and anti-interferon (IFN) autoantibodies. We found that older age correlated with an increased SARS-CoV-2 viral load at the time of admission, and with delayed viral clearance over 28 days. This contributed to an age-dependent increase in type I IFN gene expression in both the respiratory tract and blood. We also observed age-dependent transcriptional increases in peripheral blood IFN-γ, neutrophil degranulation, and Toll like receptor (TLR) signaling pathways, and decreases in T cell receptor (TCR) and B cell receptor signaling pathways. Over time, older adults exhibited a remarkably sustained induction of proinflammatory genes (e.g., CXCL6) and serum chemokines (e.g., CXCL9) compared to younger individuals, highlighting a striking age-dependent impairment in inflammation resolution. Augmented inflammatory signaling also involved the upper airway, where aging was associated with upregulation of TLR, IL17, type I IFN and IL1 pathways, and downregulation TCR and PD-1 signaling pathways. Metatranscriptomics revealed that the oldest adults exhibited disproportionate reactivation of herpes simplex virus and cytomegalovirus in the upper airway following hospitalization. Mass cytometry demonstrated that aging correlated with reduced naïve T and B cell populations, and increased monocytes and exhausted natural killer cells. Transcriptional and protein biomarkers of disease severity markedly differed with age, with the oldest adults exhibiting greater expression of TLR and inflammasome signaling genes, as well as proinflammatory proteins (e.g., IL6, CXCL8), in severe COVID-19 compared to mild/moderate disease. Anti-IFN autoantibody prevalence correlated with both age and disease severity. Taken together, this work profiles both host and microbe in the blood and airway to provide fresh insights into aging-related immune changes in a large cohort of vaccine-naïve COVID-19 patients. We observed age-dependent immune dysregulation at the transcriptional, protein and cellular levels, manifesting in an imbalance of inflammatory responses over the course of hospitalization, and suggesting potential new therapeutic targets.

Features of acute COVID-19 associated with post-acute sequelae of SARS-CoV-2 phenotypes: results from the IMPACC study.

Post-acute sequelae of SARS-CoV-2 (PASC) is a significant public health concern. We describe Patient Reported Outcomes (PROs) on 590 participants prospectively assessed from hospital admission for COVID-19 through one year after discharge. Modeling identified 4 PRO clusters based on reported deficits (minimal, physical, mental/cognitive, and multidomain), supporting heterogenous clinical presentations in PASC, with sub-phenotypes associated with female sex and distinctive comorbidities. During the acute phase of disease, a higher respiratory SARS-CoV-2 viral burden and lower Receptor Binding Domain and Spike antibody titers were associated with both the physical predominant and the multidomain deficit clusters. A lower frequency of circulating B lymphocytes by mass cytometry (CyTOF) was observed in the multidomain deficit cluster. Circulating fibroblast growth factor 21 (FGF21) was significantly elevated in the mental/cognitive predominant and the multidomain clusters. Future efforts to link PASC to acute anti-viral host responses may help to better target treatment and prevention of PASC.

Enhancing Pressure Injury Surveillance Using Natural Language Processing.

OBJECTIVE: This study assessed the feasibility of nursing handoff notes to identify underreported hospital-acquired pressure injury (HAPI) events. METHODS: We have established a natural language processing-assisted manual review process and workflow for data extraction from a corpus of nursing notes across all medical inpatient and intensive care units in a tertiary care pediatric center. This system is trained by 2 domain experts. Our workflow started with keywords around HAPI and treatments, then regular expressions, distributive semantics, and finally a document classifier. We generated 3 models: a tri-gram classifier, binary logistic regression model using the regular expressions as predictors, and a random forest model using both models together. Our final output presented to the event screener was generated using a random forest model validated using derivation and validation sets. RESULTS: Our initial corpus involved 70,981 notes during a 1-year period from 5484 unique admissions for 4220 patients. Our interrater human reviewer agreement on identifying HAPI was high ( κ = 0.67; 95% confidence interval [CI], 0.58-0.75). Our random forest model had 95% sensitivity (95% CI, 90.6%-99.3%), 71.2% specificity (95% CI, 65.1%-77.2%), and 78.7% accuracy (95% CI, 74.1%-83.2%). A total of 264 notes from 148 unique admissions (2.7% of all admissions) were identified describing likely HAPI. Sixty-one described new injuries, and 64 describe known yet possibly evolving injuries. Relative to the total patient population during our study period, HAPI incidence was 11.9 per 1000 discharges, and incidence rate was 1.2 per 1000 bed-days. CONCLUSIONS: Natural language processing-based surveillance is proven to be feasible and high yield using nursing handoff notes.

Improving anthropometric measurements in hospitalized children: A quality-improvement project.

BACKGROUND: The objective of this quality-improvement project was to increase documentation rates of anthropometrics (measured weight, length/height, and body mass index [BMI], which are critical to identify patients at malnutrition (undernutrition) risk) from <50% to 80% within 24 hours of hospital admission for pediatric patients. METHODS: Multidisciplinary champion teams on surgical, cardiac, and intensive care (ICU) pilot units were established to identify and iteratively test interventions addressing barriers to documentation from May 2016 to June 2018. Percentage of patients with documented anthropometrics <24 h of admission was assessed monthly by statistical process control methodology. Percentage of patients at malnutrition (undernutrition) risk by anthropometrics was compared by χ2 for 4 months before and after intervention. RESULTS: Anthropometric documentation rates significantly increased (P < 0.001 for all): BMI, from 11% to 89% (surgical), 33% to 57% (cardiac), and 16% to 51% (ICU); measured weight, from 24% to 88% (surgical), 69% to 83% (cardiac), and 51% to 67% (ICU); and length/height, from 12% to 89% (surgical), 38% to 57% (cardiac), and 26% to 63% (ICU). Improvement hospital-wide was observed (BMI, 42% to 70%, P < 0.001) with formal dissemination tactics. For pilot units, moderate/severe malnutrition (undernutrition) rates tripled (1.2% [24 of 2081] to 3.4% [81 of 2374], P < 0.001). CONCLUSION: Documentation of anthropometrics on admission substantially improved after establishing multidisciplinary champion teams. Goal rate (80%) was achieved within 26 months for all anthropometrics in the surgical unit and for weight in the cardiac unit. Improved documentation rates led to significant increase in identification of patients at malnutrition (undernutrition) risk.

Integrated longitudinal multi-omics study identifies immune programs associated with COVID-19 severity and mortality in 1152 hospitalized participants.

Hospitalized COVID-19 patients exhibit diverse clinical outcomes, with some individuals diverging over time even though their initial disease severity appears similar. A systematic evaluation of molecular and cellular profiles over the full disease course can link immune programs and their coordination with progression heterogeneity. In this study, we carried out deep immunophenotyping and conducted longitudinal multi-omics modeling integrating ten distinct assays on a total of 1,152 IMPACC participants and identified several immune cascades that were significant drivers of differential clinical outcomes. Increasing disease severity was driven by a temporal pattern that began with the early upregulation of immunosuppressive metabolites and then elevated levels of inflammatory cytokines, signatures of coagulation, NETosis, and T-cell functional dysregulation. A second immune cascade, predictive of 28-day mortality among critically ill patients, was characterized by reduced total plasma immunoglobulins and B cells, as well as dysregulated IFN responsiveness. We demonstrated that the balance disruption between IFN-stimulated genes and IFN inhibitors is a crucial biomarker of COVID-19 mortality, potentially contributing to the failure of viral clearance in patients with fatal illness. Our longitudinal multi-omics profiling study revealed novel temporal coordination across diverse omics that potentially explain disease progression, providing insights that inform the targeted development of therapies for hospitalized COVID-19 patients, especially those critically ill.

Inferring Viral Transmission Pathways from Within-Host Variation.

Genome sequencing can offer critical insight into pathogen spread in viral outbreaks, but existing transmission inference methods use simplistic evolutionary models and only incorporate a portion of available genetic data. Here, we develop a robust evolutionary model for transmission reconstruction that tracks the genetic composition of within-host viral populations over time and the lineages transmitted between hosts. We confirm that our model reliably describes within-host variant frequencies in a dataset of 134,682 SARS-CoV-2 deep-sequenced genomes from Massachusetts, USA. We then demonstrate that our reconstruction approach infers transmissions more accurately than two leading methods on synthetic data, as well as in a controlled outbreak of bovine respiratory syncytial virus and an epidemiologically-investigated SARS-CoV-2 outbreak in South Africa. Finally, we apply our transmission reconstruction tool to 5,692 outbreaks among the 134,682 Massachusetts genomes. Our methods and results demonstrate the utility of within-host variation for transmission inference of SARS-CoV-2 and other pathogens, and provide an adaptable mathematical framework for tracking within-host evolution.

Relationship of Heterologous Virus Responses and Outcomes in Hospitalized COVID-19 Patients.

The clinical trajectory of COVID-19 may be influenced by previous responses to heterologous viruses. We examined the relationship of Abs against different viruses to clinical trajectory groups from the National Institutes of Health IMPACC (Immunophenotyping Assessment in a COVID-19 Cohort) study of hospitalized COVID-19 patients. Whereas initial Ab titers to SARS-CoV-2 tended to be higher with increasing severity (excluding fatal disease), those to seasonal coronaviruses trended in the opposite direction. Initial Ab titers to influenza and parainfluenza viruses also tended to be lower with increasing severity. However, no significant relationship was observed for Abs to other viruses, including measles, CMV, EBV, and respiratory syncytial virus. We hypothesize that some individuals may produce lower or less durable Ab responses to respiratory viruses generally (reflected in lower baseline titers in our study), and that this may carry over into poorer outcomes for COVID-19 (despite high initial SARS-CoV-2 titers). We further looked at longitudinal changes in Ab responses to heterologous viruses, but found little change during the course of acute COVID-19 infection. We saw significant trends with age for Ab levels to many of these viruses, but no difference in longitudinal SARS-CoV-2 titers for those with high versus low seasonal coronavirus titers. We detected no difference in longitudinal SARS-CoV-2 titers for CMV seropositive versus seronegative patients, although there was an overrepresentation of CMV seropositives among the IMPACC cohort, compared with expected frequencies in the United States population. Our results both reinforce findings from other studies and suggest (to our knowledge) new relationships between the response to SARS-CoV-2 and Abs to heterologous viruses.

Incidence of Hospital-Acquired Conditions During Pediatric Clinical Research Inpatient Hospitalizations: A Matched Cohort Study.

OBJECTIVES: In this matched cohort study using data from pediatric hospitals, we compared the incidence of hospital-acquired conditions (HACs) during clinical research hospitalizations to nonresearch hospitalizations. METHODS: Using Pediatric Health Information System data for inpatient discharges January 2017-June 2022, we matched research hospitalizations (identified by International Classification of Diseases, Tenth Revision, diagnosis code) to nonresearch hospitalizations within hospital on age (±3 y), sex, discharge year (±2), and All Patients Refined Diagnosis Related Groups classification, severity of illness (±1), and risk of mortality (±1). We calculated the incidence (per 1000 discharges) and incidence rate (per 10,000 patient days) of HAC identified by International Classification of Diseases, Tenth Revision, codes and compare research versus nonresearch using logistic and Poisson regression, accounting for matching using generalized estimating equations and adjusting for sociodemographic factors and hospital utilization. RESULTS: We matched 7000 research hospitalizations to 26,447 nonresearch from 28 hospitals. Median age was 6.0 years (interquartile range, 10.6 y). Median length of stay was 4.0 days (interquartile range, 11.0 days) with longer stays among research hospitalizations ( P < 0.001). Incidence of HAC among research hospitalizations was 13.1 versus 7.2 per 1000 for nonresearch ( P < 0.001) and incidence rate 6.7 versus 4.5 per 10,000 patient days. Adjusting for sociodemographic and clinical factors, research stays had 1.65 times the odds of any HAC (95% confidence interval, 1.27-2.16; P < 0.001) and 1.38 times the incidence rate (95% confidence interval, 1.09-1.75; P = 0.009). CONCLUSIONS: Our findings indicate that pediatric research hospitalizations are more likely to experience HACs compared with nonresearch hospitalizations. These findings have important safety implications for pediatric inpatient clinical research that warrant further study.

A protocol for high-throughput screening for immunomodulatory compounds using human primary cells.

High-throughput screening is a powerful platform that can rapidly provide valuable cytotoxic, immunological, and phenotypical information for thousands of compounds. Human peripheral blood mononuclear cells (PBMCs) cultured in autologous plasma can model the human immune response. Here, we describe a protocol to stimulate PBMCs for 72 h and measure cytokine secretion via AlphaLISA assays and cell surface activation marker expression via flow cytometry. Cryopreserved PBMCs are incubated for 72 h with various small molecule libraries and the supernatants are harvested to rapidly measure secretion levels of key cytokines (tumor necrosis factor alpha, interferon gamma, interleukin 10) via the AlphaLISA assay. Almost simultaneously, the cells can be fixated and stained using antibodies against innate immune activation markers (CD80, CD86, HLA-DR, OX40) for analysis via flow cytometry. This multiplexed readout workflow can directly aid in the phenotypic identification and discovery of novel immunomodulators and potential vaccine adjuvant candidates. For complete details on the use and execution of this protocol, please refer to Chew et al.1.

Effective early antiretroviral therapy in perinatal-HIV infection reduces subsequent plasma inflammatory profile.

BACKGROUND: The long-term immunologic effects of antiretroviral therapy (ART) in children with perinatally-acquired HIV (PHIV) have not been fully elucidated. Here, we investigated how the timing of ART initiation affects the long-term immune profile of children living with PHIV by measuring immunomodulatory plasma cytokines, chemokines, and adenosine deaminases (ADAs). METHODS: 40 PHIV participants initiated ART during infancy. 39 participant samples were available; 30 initiated ART ≤6 months (early-ART treatment); 9 initiated ART >6 months and <2 years (late-ART treatment). We compared plasma cytokine and chemokine concentrations and ADA enzymatic activities between early-ART and late-ART treatment 12.5 years later and measured correlation with clinical covariates. RESULTS: Plasma concentrations of 10 cytokines and chemokines (IFNγ, IL-12p70, IL-13, IL-17A, IL-IRA, IL-5, IL-6, and IL-9 as well as CCL7, CXCL10), ADA1, and ADA total were significantly higher in late-ART compared to early-ART treatment. Furthermore, ADA1 was significantly positively correlated with IFNγ, IL-17A, and IL-12p70. Meanwhile, total ADA was positively correlated with IFNγ, IL-13, IL-17A, IL-1RA, IL-6, and IL-12p70 as well as CCL7. CONCLUSIONS: Elevation of several pro-inflammatory plasma analytes in late-ART despite 12.5 years of virologic suppression compared to early-ART treatment suggests that early treatment dampens the long-term plasma inflammatory profile in PHIV participants. IMPACT: This study examines differences in the plasma cytokine, chemokine, and ADA profiles 12.5 years after treatment between early (≤6months) and late (>6 months and <2 years) antiretroviral therapy (ART) treatment initiation in a cohort of European and UK study participants living with PHIV. Several cytokines and chemokines (e.g., IFNγ, IL-12p70, IL-6, and CXCL10) as well as ADA-1 are elevated in late-ART treatment in comparison to early-ART treatment. Our results suggest that effective ART treatment initiated within 6 months of life in PHIV participants dampens a long-term inflammatory plasma profile as compared to late-ART treatment.

Multi-omic longitudinal study reveals immune correlates of clinical course among hospitalized COVID-19 patients.

The IMPACC cohort, composed of >1,000 hospitalized COVID-19 participants, contains five illness trajectory groups (TGs) during acute infection (first 28 days), ranging from milder (TG1-3) to more severe disease course (TG4) and death (TG5). Here, we report deep immunophenotyping, profiling of >15,000 longitudinal blood and nasal samples from 540 participants of the IMPACC cohort, using 14 distinct assays. These unbiased analyses identify cellular and molecular signatures present within 72 h of hospital admission that distinguish moderate from severe and fatal COVID-19 disease. Importantly, cellular and molecular states also distinguish participants with more severe disease that recover or stabilize within 28 days from those that progress to fatal outcomes (TG4 vs. TG5). Furthermore, our longitudinal design reveals that these biologic states display distinct temporal patterns associated with clinical outcomes. Characterizing host immune responses in relation to heterogeneity in disease course may inform clinical prognosis and opportunities for intervention.

Comparative Impact Analysis of Low-Deductible Insurance Versus In-house Hospital Assumption of Risk and Management on Medical Malpractice Claims.

OBJECTIVES: Claims management is critical to ensure the safe and high-quality medical care for which liability insurers and/or hospitals are responsible. The aim of this research is to determine whether increasing hospital malpractice risk exposure, with increasing deductibles, has an impact on malpractice claims and payouts. METHODS: The study was conducted at a single tertiary hospital, the Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy. Payouts on closed reported and registered claims were analyzed during 4-study periods, which ranged from 1.5 million euro annual aggregate deductibles entirely managed by the insurance company to 5 million euro annual aggregate deductibles entirely managed by the hospital. We retrospectively analyzed 2034 medical malpractice claims submitted between January 1, 2007, and August 31, 2021. Four periods were examined depending on the claims management model adopted, ranging from total outsourcing to the insurer (period A) to an almost total hospital assumption of risk method (period D). RESULTS: We found that progressive hospital assumption of risk is associated with a decrease in the incidence of medical malpractice claims (average variation per year: -3.7%; P = 0.0029 if the 2 initial periods and the 2 last periods-characterized by the highest risk retention-are respectively aggregated and compared), an initial decrease in the mean claims cost followed by an increase that is still lower than the national increase (-5.4% on average), and an increase in the total claims cost (when compared with the period where the insurer solely managed claims). We also found that the rate of increase in payouts was less than the national average. CONCLUSIONS: The assumption of more malpractice risk by the hospital was associated with the adoption of numerous patient safety and risk management initiatives. The decrease in claims incidence could be due to the implementation of patient safety policies, while the cost increase could be attributed to inflation and rising costs of healthcare services and claims. Notably, only the hospital assumption of risk model with a high-deductible insurance coverage is sustainable for the studied hospital, while also being profitable for the insurer. In conclusion, as hospitals progressively assumed more risk and management responsibility of malpractice claims, there was a progressive decrease in the total number of claims, and a less rapid rise in claim payouts as compared with the national average. Even a small assumption of risk appeared to elicit meaningful changes in claim filings and payouts.

Volume and Severity of Pediatric COVID-19 Hospitalizations in the United States.

OBJECTIVES: Using administrative data from pediatric hospitals in the United States, we examined trends in coronavirus disease 2019 (COVID-19) hospitalizations and severity of disease among children. METHODS: We extracted data from the Pediatric Health Information System for hospitalized patients less than 12 years old with COVID-19 (identified by primary or secondary International Classification of Diseases-10 diagnosis code U07.1) admitted from April 2020 to August 2022. We examined weekly trends in COVID hospitalization volume overall and by ICU utilization as a measure of severe disease and by COVID diagnosis hierarchy (primary versus secondary) as a proxy for incidental admissions. We estimated the annualized trend in the ratio of hospitalizations requiring, versus not requiring, ICU care and the trend in ratio of hospitalizations with a primary versus secondary COVID diagnosis. RESULTS: We included 38 160 hospitalizations across 45 hospitals. Median age was 2.4 years (interquartile range = 0.7-6.6). Median length of stay was 2.0 days (interquartile range = 1-4). ICU-level care was required for 18.9% and 53.8% had a primary diagnosis of COVID-19. The ratio of ICU to non-ICU admissions declined by 14.5% annually (95% confidence interval: -21.7% to -7.26%; P < .001), whereas the ratio of primary to secondary diagnosis was stable (11.7% annually; 95% confidence interval: -8.83% to 32.4%; P = .26). CONCLUSIONS: Periodic increases in pediatric COVID-19 hospitalizations with are evident. However, there is no evidence of corresponding increase in severity of illness that may provide context for recent reports of increasing pediatric COVID hospitalizations in addition to health policy implications.

Carbohydrate fatty acid monosulphate: oil-in-water adjuvant enhances SARS-CoV-2 RBD nanoparticle-induced immunogenicity and protection in mice.

Development of SARS-CoV-2 vaccines that protect vulnerable populations is a public health priority. Here, we took a systematic and iterative approach by testing several adjuvants and SARS-CoV-2 antigens to identify a combination that elicits antibodies and protection in young and aged mice. While demonstrating superior immunogenicity to soluble receptor-binding domain (RBD), RBD displayed as a protein nanoparticle (RBD-NP) generated limited antibody responses. Comparison of multiple adjuvants including AddaVax, AddaS03, and AS01B in young and aged mice demonstrated that an oil-in-water emulsion containing carbohydrate fatty acid monosulphate derivative (CMS:O/W) most effectively enhanced RBD-NP-induced cross-neutralizing antibodies and protection across age groups. CMS:O/W enhanced antigen retention in the draining lymph node, induced injection site, and lymph node cytokines, with CMS inducing MyD88-dependent Th1 cytokine polarization. Furthermore, CMS and O/W synergistically induced chemokine production from human PBMCs. Overall, CMS:O/W adjuvant may enhance immunogenicity and protection of vulnerable populations against SARS-CoV-2 and other infectious pathogens.