Publications by authors named "James Chappell"

Background: Guidelines state that all hospitalized children with suspected or confirmed influenza receive prompt treatment with influenza-specific antivirals. We sought to determine the frequency of, and factors associated with, antiviral receipt among hospitalized children.

Methods: We conducted active surveillance of children presenting with fever or respiratory symptoms from 1 December 2016 to 31 March 2020 at 7 pediatric medical centers in the New Vaccine Surveillance Network.

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SARS-CoV-2 has undergone repeated and rapid evolution to circumvent host immunity. However, outside of prolonged infections in immunocompromised hosts, within-host positive selection has rarely been detected. The low diversity within-hosts and strong genetic linkage among genomic sites make accurately detecting positive selection difficult.

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In a population-based birth cohort study of respiratory syncytial virus surveillance in the United States, 897/1,680 (53.4%) children were infected during infancy; 25 (2.8%) of those were hospitalized.

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The Cold Spring Harbor Laboratory (CSHL) Summer Course on Synthetic Biology, established in 2013, has emerged as a premier platform for immersive education and research in this dynamic field. Rooted in CSHL's rich legacy of biological discovery, the course offers a comprehensive exploration of synthetic biology's fundamentals and applications. Led by a consortium of faculty from diverse institutions, the course structure seamlessly integrates practical laboratory sessions, exploratory research rotations, and enriching seminars by leaders in the field.

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Article Synopsis
  • Rotavirus was a major cause of gastroenteritis in US children until the introduction of vaccines in 2006, which led to significant reductions in severe cases.
  • A study from 2009 to 2022 analyzed vaccine effectiveness (VE) using data from children with acute gastroenteritis, revealing a 78% effectiveness rate against severe rotavirus-related medical visits.
  • The effectiveness varied by severity of disease, showing 94% effectiveness against very severe cases, with younger children benefiting the most from vaccination.
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Isolation of symptomatic infectious persons can reduce influenza transmission. However, virus shedding that occurs without symptoms will be unaffected by such measures. Identifying effective isolation strategies for influenza requires understanding the interplay between individual virus shedding and symptom presentation.

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Households are a primary setting for transmission of SARS-CoV-2. We examined the role of prior SARS-CoV-2 immunity on the risk of infection in household close contacts. Households in the United States with an individual who tested positive for SARS-CoV-2 during September 2021-May 2023 were enrolled if the index case's illness began ≤6 days prior.

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Enzymes that produce volatile metabolites can be coded into genetic circuits to report nondisruptively on microbial behaviors in hard-to-image soils. However, these enzyme reporters remain challenging to apply in gene transfer studies due to leaky off states that can lead to false positives. To overcome this problem, we designed a reporter that uses ribozyme-mediated gene-fragment complementation of a methyl halide transferase (MHT) to regulate the synthesis of methyl halide gases.

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Article Synopsis
  • The study assessed the effectiveness of the updated 2023-2024 COVID-19 vaccine against hospitalization for two variant lineages, XBB and JN, in hospitalized patients across 26 hospitals in the U.S. between October 2023 and March 2024.
  • The results indicated a vaccine effectiveness (VE) of 54.2% against XBB and 32.7% against JN, suggesting that the JN lineage may have some level of immune escape.
  • However, the severity of cases with the JN lineage was not significantly worse compared to those with the XBB lineage, indicating similar risks of severe outcomes like ICU admission and death.
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Background: Understanding how symptoms are associated with SARS-CoV-2 culture positivity is important for isolation and transmission control guidelines.

Methods: Individuals acutely infected with SARS-CoV-2 in Tennessee and their household contacts were recruited into a prospective study. All participants self-collected nasal swabs daily for 14 days and completed symptom diaries from the day of illness onset through day 14 postenrollment.

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Article Synopsis
  • Human rotaviruses have limited ability to grow in most cell lines, with the VP4 protein being crucial for their attachment and replication.
  • Researchers studied 50 clinical specimens from five key rotavirus genotypes, passing them through monkey kidney cells to observe adaptations.
  • They discovered conserved mutations in the VP4 protein that could help in understanding rotavirus biology and potentially aid in vaccine development.
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Introduction: Traditional surveillance systems may underestimate the burden caused by respiratory syncytial virus (RSV). Capture-recapture methods provide alternatives for estimating the number of RSV-related hospitalizations in a population.

Methods: Capture-recapture methods were used to estimate the number of RSV-related hospitalizations in adults in Middle Tennessee from two independent hospitalization surveillance systems during consecutive respiratory seasons from 2016-2017 to 2019-2020.

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Objective: Acute gastroenteritis (AGE) is the second leading cause of death in children worldwide. Objectively evaluating disease severity is critical for assessing future interventions. We used data from a large, prospective surveillance study to assess risk factors associated with severe presentation using modified Vesikari score (MVS) and Clark score (CS) of severity.

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Importance: On June 21, 2023, the Centers for Disease Control and Prevention recommended the first respiratory syncytial virus (RSV) vaccines for adults aged 60 years and older using shared clinical decision-making. Understanding the severity of RSV disease in adults can help guide this clinical decision-making.

Objective: To describe disease severity among adults hospitalized with RSV and compare it with the severity of COVID-19 and influenza disease by vaccination status.

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Objective: Evaluate the association between provider-ordered viral testing and antibiotic treatment practices among children discharged from an ED or hospitalized with an acute respiratory infection (ARI).

Design: Active, prospective ARI surveillance study from November 2017 to February 2020.

Setting: Pediatric hospital and emergency department in Nashville, Tennessee.

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Article Synopsis
  • In September 2023, the CDC recommended the updated 2023-2024 monovalent XBB.1.5 COVID-19 vaccine for everyone aged 6 months and older to help prevent COVID-19, including severe cases.
  • An analysis of vaccine effectiveness (VE) found that during the first 59 days after vaccination, the VE against COVID-19-related emergency department visits was 51%, which dropped to 39% after 60-119 days.
  • The updated COVID-19 vaccine showed increased protection, with VE against hospitalizations being 52% and 43% between two networks, supporting CDC's guidelines for vaccination.
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Pediatric hematopoietic cell transplant (HCT) recipients exhibit poor serologic responses to influenza vaccination early after transplant. To facilitate the optimization of influenza vaccination timing, we sought to identify B- and T-cell subpopulations associated with influenza vaccine immunogenicity in this population. We used mass cytometry to phenotype peripheral blood mononuclear cells collected from pediatric HCT recipients enrolled in a multicenter influenza vaccine trial comparing high- and standard-dose formulations over 3 influenza seasons (2016-2019).

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Article Synopsis
  • Respiratory syncytial virus (RSV) is a major cause of respiratory illnesses in young children, divided into two main subtypes: A and B, which circulate variably around the world without a clear link to severity of illness.
  • A study conducted from 2016 to 2020 involving nearly 6400 RSV-positive children under 5 years old in the US found that more children were infected with RSV-A compared to RSV-B, with RSV-A linked to higher hospitalization rates.
  • Results underscore that while RSV-A and RSV-B show similar clinical impacts, their prevalence varies by season and region, emphasizing the need for ongoing surveillance, especially with new prevention options on the horizon.
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  • Prolonged SARS-CoV-2 infections may pose a risk for the development of mutated variants, particularly in immunocompromised individuals, but the specific types of immunosuppressive conditions that increase this risk have not been extensively studied.
  • A study conducted across five US medical centers involved 150 immunocompromised patients to identify factors contributing to extended SARS-CoV-2 infections through regular testing and genetic sequencing.
  • Results showed that patients with B-cell dysfunction and those who had solid organ transplants or HIV had longer durations of infection compared to those with autoimmune conditions, indicating varying risks based on the type of immunosuppression.
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While the research community continues to develop novel proposals for intrinsic biocontainment of genetically engineered organisms, translation to real-world deployment faces several challenges.

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Background And Objectives: Factors prompting clinicians to request viral testing in children are unclear. We assessed patterns prompting clinicians to perform viral testing in children discharged from an emergency department (ED) or hospitalized with an acute respiratory infection (ARI).

Methods: Using active ARI surveillance data collected from November 2017 through February 2020, children aged between 30 days and 17 years with fever or respiratory symptoms who had a research respiratory specimen tested were included.

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