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Coordinated navigation within tissues is essential for cells of the innate immune system to reach the sites of inflammatory processes, but the signals involved are incompletely understood. Here we demonstrate that NG2(+) pericytes controlled the pattern and efficacy of the interstitial migration of leukocytes in vivo. In response to inflammatory mediators, pericytes upregulated expression of the adhesion molecule ICAM-1 and released the chemoattractant MIF. Arteriolar and capillary pericytes attracted and interacted with myeloid leukocytes after extravasating from postcapillary venules, 'instructing' them with pattern-recognition and motility programs. Inhibition of MIF neutralized the migratory cues provided to myeloid leukocytes by NG2(+) pericytes. Hence, our results identify a previously unknown role for NG2(+) pericytes as an active component of innate immune responses, which supports the immunosurveillance and effector function of extravasated neutrophils and macrophages.
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Molécula 1 de Adhesión Intercelular/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Leucocitos/inmunología , Factores Inhibidores de la Migración de Macrófagos/metabolismo , Pericitos/inmunología , Receptores de Reconocimiento de Patrones/inmunología , Anticuerpos Bloqueadores/farmacología , Arteriolas/inmunología , Capilares/inmunología , Comunicación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Células Cultivadas , Humanos , Inmunidad Innata , Mediadores de Inflamación/metabolismo , Molécula 1 de Adhesión Intercelular/genética , Oxidorreductasas Intramoleculares/genética , Oxidorreductasas Intramoleculares/inmunología , Leucocitos/efectos de los fármacos , Factores Inhibidores de la Migración de Macrófagos/genética , Factores Inhibidores de la Migración de Macrófagos/inmunología , Activación Neutrófila/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Vénulas/inmunologíaRESUMEN
Estimating strain on surfaces of deforming three-dimensional (3D) structures is a critical need in experimental mechanics. Although single-camera techniques excel at estimating deformation on a surface parallel to the imaging plane, they are prone to artifact for 3D motion because they cannot distinguish between out-of-plane motion and in-plane dilatation. Multiview (e.g., stereo) camera systems overcome this via a three-step process consisting of: (1) independent surface registration, (2) triangulation to estimate surface displacements, and (3) deformation estimation. However, existing methods are prone to errors associated with numerical differentiation when computing estimating strain fields from displacement fields unless regularization schemes are used. Such regularization schemes can introduce inaccuracy into strain estimation. Inspired by previous work which combined registration and deformation estimation into a single step for 2D images and 3D imaging stacks, we developed a theory for simultaneous image registration, 3D triangulation, and deformation estimation in a multiview system. The deformation estimation does not require numerical differentiation of displacement fields to estimate strain fields. We present here the theoretical foundations and derivation of two related implementations of this approach, and discuss their strengths and weaknesses.
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Imagenología Tridimensional , Algoritmos , Fantasmas de ImagenRESUMEN
Quantifying dynamic strain fields from time-resolved volumetric medical imaging and microscopy stacks is a pressing need for radiology and mechanobiology. A critical limitation of all existing techniques is regularization: because these volumetric images are inherently noisy, the current strain mapping techniques must impose either displacement regularization and smoothing that sacrifices spatial resolution, or material property assumptions that presuppose a material model, as in hyperelastic warping. Here, we present, validate, and apply the first three-dimensional (3D) method for estimating mechanical strain directly from raw 3D image stacks without either regularization or assumptions about material behavior. We apply the method to high-frequency ultrasound images of mouse hearts to diagnose myocardial infarction. We also apply the method to present the first ever in vivo quantification of elevated strain fields in the heart wall associated with the insertion of the chordae tendinae. The method shows promise for broad application to dynamic medical imaging modalities, including high-frequency ultrasound, tagged magnetic resonance imaging, and confocal fluorescence microscopy.
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Corazón/diagnóstico por imagen , Imagenología Tridimensional , Animales , Corazón/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Músculos Papilares/diagnóstico por imagen , Músculos Papilares/patología , Músculos Papilares/fisiopatología , UltrasonografíaRESUMEN
Short-term fasting protects mice from lethal doses of chemotherapy through undetermined mechanisms. Herein, we demonstrate that fasting preserves small intestinal (SI) architecture by maintaining SI stem cell viability and SI barrier function following exposure to high-dose etoposide. Nearly all SI stem cells were lost in fed mice, whereas fasting promoted sufficient SI stem cell survival to preserve SI integrity after etoposide treatment. Lineage tracing demonstrated that multiple SI stem cell populations, marked by Lgr5, Bmi1, or HopX expression, contributed to fasting-induced survival. DNA repair and DNA damage response genes were elevated in SI stem/progenitor cells of fasted etoposide-treated mice, which importantly correlated with faster resolution of DNA double-strand breaks and less apoptosis. Thus, fasting preserved SI stem cell viability as well as SI architecture and barrier function suggesting that fasting may reduce host toxicity in patients undergoing dose intensive chemotherapy.
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Daño del ADN , Ayuno/metabolismo , Intestino Delgado/metabolismo , Intestino Delgado/patología , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Roturas del ADN de Doble Cadena , Reparación del ADN , Etopósido/administración & dosificación , Etopósido/efectos adversos , Femenino , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Intestino Delgado/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Células Madre/patologíaRESUMEN
Whether measured by MRI or direct cortical physiology, infraslow rhythms have defined state invariant cortical networks. The time scales of this functional architecture, however, are unlikely to be able to accommodate the more rapid cortical dynamics necessary for an active cognitive task. Using invasively monitored epileptic patients as a research model, we tested the hypothesis that faster frequencies would spectrally bind regions of cortex as a transient mechanism to enable fast network interactions during the performance of a simple hear-and-repeat speech task. We term these short-lived spectrally covariant networks functional spectral networks (FSNs). We evaluated whether spectrally covariant regions of cortex, which were unique in their spectral signatures, provided a higher degree of task-related information than any single site showing more classic physiologic responses (i.e., single-site amplitude modulation). Taken together, our results showing that FSNs are a more sensitive measure of task-related brain activation and are better able to discern phonemic content strongly support the concept of spectrally encoded interactions in cortex. Moreover, these findings that specific linguistic information is represented in FSNs that have broad anatomic topographies support a more distributed model of cortical processing.
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Corteza Cerebral/fisiología , Electroencefalografía , Humanos , Imagen por Resonancia MagnéticaRESUMEN
Immune-mediated pulmonary diseases are a significant public health concern. Analysis of leukocyte behavior in the lung is essential for understanding cellular mechanisms that contribute to normal and diseased states. Here, we used two-photon imaging to study neutrophil extravasation from pulmonary vessels and subsequent interstitial migration. We found that the lungs contained a significant pool of tissue-resident neutrophils in the steady state. In response to inflammation produced by bacterial challenge or transplant-mediated, ischemia-reperfusion injury, neutrophils were rapidly recruited from the circulation and patrolled the interstitium and airspaces of the lung. Motile neutrophils often aggregated in dynamic clusters that formed and dispersed over tens of minutes. These clusters were associated with CD115(+) F4/80(+) Ly6C(+) cells that had recently entered the lung. The depletion of blood monocytes with clodronate liposomes reduced neutrophil clustering in the lung, but acted by inhibiting neutrophil transendothelial migration upstream of interstitial migration. Our results suggest that a subset of monocytes serve as key regulators of neutrophil extravasation in the lung and may be an attractive target for the treatment of inflammatory pulmonary diseases.
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Pulmón/citología , Microscopía/métodos , Monocitos/citología , Neutrófilos/citología , Animales , Quimiotaxis de Leucocito , Ratones , FotonesRESUMEN
Background: Age and certain medical/social conditions are risk factors for invasive pneumococcal disease (IPD). For prevention of IPD, the National Advisory Committee on Immunization (NACI) has recommended the 23-valent polysaccharide pneumococcal vaccine, PNEU-P-23, for adults 65 years of age and older and adults over 18 years of age living with certain underlying conditions. NACI has also recommended 13-valent conjugate pneumococcal vaccine, PNEU-C-13, for adults; however, in publicly funded programs, this recommendation is limited to individuals with risk factors for IPD. Two new conjugate vaccines, PNEU-C-15 and PNEU-C-20, have been authorized by Health Canada for prevention of IPD in adults. This article summarizes NACI public health recommendations for pneumococcal vaccines in adults given these new conjugate vaccines that provide additional serotype coverage over PNEU-C-13. Methods: Key studies evaluating the immunogenicity and safety of PNEU-C-15 and PNEU-C-20 were reviewed. The Grading of Recommendations, Assessment, Development and Evaluations framework methodology was used to assess the certainty of evidence. Results: The PNEU-C-15 and PNEU-C-20 vaccines showed comparable immune responses, and safety profiles for all mild, moderate, and severe adverse events, to the currently used vaccines. No data were available on the efficacy or effectiveness of PNEU-C-15 or PNEU-C-20. Economic evidence and feasibility assessments supported the use of the PNEU-C-20 vaccine. Conclusion: NACI recommends PNEU-C-20 for adults 65 years of age and older, 50-64 years of age and living with factors placing them at higher risk of pneumococcal disease, and 18-49 years of age with immunocompromising conditions, with PNEU-C-15+PNEU-P-23 an alternative.
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We explore the use of deep convolutional neural networks (CNNs) trained on overhead imagery of biomass sorghum to ascertain the relationship between single nucleotide polymorphisms (SNPs), or groups of related SNPs, and the phenotypes they control. We consider both CNNs trained explicitly on the classification task of predicting whether an image shows a plant with a reference or alternate version of various SNPs as well as CNNs trained to create data-driven features based on learning features so that images from the same plot are more similar than images from different plots, and then using the features this network learns for genetic marker classification. We characterize how efficient both approaches are at predicting the presence or absence of a genetic markers, and visualize what parts of the images are most important for those predictions. We find that the data-driven approaches give somewhat higher prediction performance, but have visualizations that are harder to interpret; and we give suggestions of potential future machine learning research and discuss the possibilities of using this approach to uncover unknown genotype × phenotype relationships.
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We conducted a case-control study to describe the clinical and epidemiologic characteristics of an outbreak of pandemic (H1N1) 2009 at a Canadian military cadet training center. We found that asthma and obesity confer greater risk for infection. Viral shedding was detected by PCR up to 18 days after symptom onset.
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Brotes de Enfermedades , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Gripe Humana/epidemiología , Personal Militar , Adolescente , Adulto , Asma/epidemiología , Canadá/epidemiología , Estudios de Casos y Controles , Tos/diagnóstico , Tos/epidemiología , Femenino , Fiebre/diagnóstico , Fiebre/epidemiología , Humanos , Masculino , Obesidad/epidemiología , Factores de Riesgo , Esparcimiento de VirusRESUMEN
The Council for the International Organizations of Medical Sciences (CIOMS) and WHO working group on pharmacovigilance defines five cause specific AEFI which includes an immunization anxiety-related reaction. Historically this term has been used to describe a range of symptoms and signs that may arise after immunization that are related to "anxiety" about the immunization. However, the term "anxiety" does not adequately capture all the elements of this cause specific AEFI. In 2015, the Global Advisory Committee for Vaccine Safety convened an expert working group with the purpose of redefining, preventing and managing this particular AEFI. The term "Immunization Stress-Related Response" is proposed to replace the former terminology. We present a manual that redefines this AEFI and present a framework for prevention, diagnosis and management in both an individual and also when such events occur as clusters and affect multiple individuals. Since such mass events can result in cessation of immunization programmes and/or a loss of public confidence, a communication response is essential.
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Ansiedad , Vacunación/psicología , Vacunas , Humanos , Programas de Inmunización , Vacunación/efectos adversos , Vacunas/efectos adversosRESUMEN
BACKGROUND: Measurement of plant traits with precision and speed on large populations has emerged as a critical bottleneck in connecting genotype to phenotype in genetics and breeding. This bottleneck limits advancements in understanding plant genomes and the development of improved, high-yielding crop varieties. RESULTS: Here we demonstrate the application of deep learning on proximal imaging from a mobile field vehicle to directly estimate plant morphology and developmental stages in wheat under field conditions. We developed and trained a convolutional neural network with image datasets labeled from expert visual scores and used this "breeder-trained" network to classify wheat morphology and developmental stages. For both morphological (awned) and phenological (flowering time) traits, we demonstrate high heritability and very high accuracy against the "ground-truth" values from visual scoring. Using the traits predicted by the network, we tested genotype-to-phenotype association using the deep learning phenotypes and uncovered novel epistatic interactions for flowering time. Enabled by the time-series high-throughput phenotyping, we describe a new phenotype as the rate of flowering and show heritable genetic control for this trait. CONCLUSIONS: We demonstrated a field-based high-throughput phenotyping approach using deep learning that can directly measure morphological and developmental phenotypes in genetic populations from field-based imaging. The deep learning approach presented here gives a conceptual advancement in high-throughput plant phenotyping because it can potentially estimate any trait in any plant species for which the combination of breeder scores and high-resolution images can be obtained, capturing the expert knowledge from breeders, geneticists, pathologists, and physiologists to train the networks.
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Bases de Datos de Ácidos Nucleicos , Aprendizaje Profundo , Flores , Regulación de la Expresión Génica de las Plantas , Estudios de Asociación Genética , Genotipo , Triticum , Flores/genética , Flores/metabolismo , Triticum/genética , Triticum/metabolismoRESUMEN
Pharmacovigilance is defined as the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other possible drug-related problems.1 While current models of pharmacovigilance, with their tools and methodologies, were developed for prescription drugs, safety surveillance is just as important for over-the-counter health products such as dietary supplements. The practice of pharmacovigilance is challenging in itself; however, there are unique challenges associated with dietary supplements.2.
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Seguridad de Productos para el Consumidor , Suplementos Dietéticos/efectos adversos , Seguridad del Paciente , Farmacovigilancia , Fitoterapia/efectos adversos , Preparaciones de Plantas/efectos adversos , Control de Calidad , Pruebas de Toxicidad , Animales , Seguridad de Productos para el Consumidor/normas , Suplementos Dietéticos/normas , Predicción , Humanos , Seguridad del Paciente/normas , Fitoterapia/normas , Fitoterapia/tendencias , Preparaciones de Plantas/normas , Mejoramiento de la Calidad , Medición de Riesgo , Pruebas de Toxicidad/normas , Pruebas de Toxicidad/tendenciasRESUMEN
We describe the presenting features and long-term outcome of an unusual cluster of pediatric acute flaccid paralysis cases that occurred in Canada during the 2014 enterovirus D68 outbreak. Children (n = 25; median age 7.8 years) presenting to Canadian centers between July 1 and October 31, 2014, and who met diagnostic criteria for acute flaccid paralysis were evaluated retrospectively. The predominant presenting features included prodromal respiratory illness (n = 22), cerebrospinal fluid lymphocytic pleocytosis (n = 18), pain in neck/back (n = 14) and extremities (n = 10), bowel/bladder dysfunction (n = 9), focal central gray matter lesions found in all regions of the spinal cord within the cohort (n = 16), brain stem lesions (n = 8), and bulbar symptoms (n = 5). Enterovirus D68 was detectable in nasopharyngeal specimens (n = 7) but not in cerebrospinal fluid. Acute therapies (corticosteroids, intravenous immunoglobulins, plasmapheresis) were well tolerated with few side effects. Fourteen of 16 patients who were followed beyond 12 months post onset had neurologic deficits but showed ongoing clinical improvement and motor recovery.
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Encéfalo/diagnóstico por imagen , Enterovirus Humano D , Infecciones por Enterovirus/complicaciones , Paraplejía/terapia , Potenciales de Acción/fisiología , Adolescente , Corticoesteroides/uso terapéutico , Canadá , Niño , Preescolar , Electromiografía , Infecciones por Enterovirus/fisiopatología , Femenino , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Lactante , Masculino , Músculo Esquelético/fisiopatología , Conducción Nerviosa/fisiología , Paraplejía/diagnóstico por imagen , Paraplejía/tratamiento farmacológico , Paraplejía/virología , Plasmaféresis , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
INTRODUCTION: Active transportation opportunities and infrastructure are an important component of a community's design, livability, and health. Features of the built environment influence active transportation, but objective study of the natural experiment effects of built environment improvements on active transportation is challenging. The purpose of this study was to develop and present a novel method of active transportation research using webcams and crowdsourcing, and to determine if crosswalk enhancement was associated with changes in active transportation rates, including across a variety of weather conditions. METHODS: The 20,529 publicly available webcam images from two street intersections in Washington, DC, USA were used to examine the impact of an improved crosswalk on active transportation. A crowdsource, Amazon Mechanical Turk, annotated image data. Temperature data were collected from the National Oceanic and Atmospheric Administration, and precipitation data were annotated from images by trained research assistants. RESULTS: Summary analyses demonstrated slight, bi-directional differences in the percent of images with pedestrians and bicyclists captured before and after the enhancement of the crosswalks. Chi-square analyses revealed these changes were not significant. In general, pedestrian presence increased in images captured during moderate temperatures compared to images captured during hot or cold temperatures. Chi-square analyses indicated the crosswalk improvement may have encouraged walking and biking in uncomfortable outdoor conditions (P < 0.5). CONCLUSION: The methods employed provide an objective, cost-effective alternative to traditional means of examining the effects of built environment changes on active transportation. The use of webcams to collect active transportation data has applications for community policymakers, planners, and health professionals. Future research will work to validate this method in a variety of settings as well as across different built environment and community policy initiatives.
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In 1999, the Global Advisory Committee on Vaccine Safety (GACVS) was established by the World Health Organization (WHO) to provide independent scientific advice on issues relating to the safety of vaccines and immunization. Fifteen years onward, we conducted a multi-faceted review to evaluate the impact, reach and challenges facing GACVS, including the role GACVS plays in informing global, regional and WHO member state vaccine policy. The methods included measures of organizational structure, citation impact, themes approached, and a discussion by previous and current members to evaluate past, present and future challenges. Given the increasing range of data sources and the deployment of many new vaccines, the Committee is facing the complex task of identifying the best available evidence for recommendations on vaccine safety. To help meet the increased demand for public transparency in decision making, GACVS-structured methodology for evidence-based decisions is evolving. GACVS also promotes best practices and capacity building for timely and accurate risk assessment; risk communications; outreach to help countries maintain and, if needed, rebuild public trust in vaccines; and advocacy for bridging the major gaps in vaccine safety capacity globally.
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Comités Consultivos/organización & administración , Seguridad de Productos para el Consumidor , Vacunas/normas , Política de Salud , Humanos , Organización Mundial de la SaludRESUMEN
Immunization in pregnancy provides a promising contribution to globally reducing neonatal and under-five childhood mortality and morbidity. Thorough assessment of benefits and risks for the primarily healthy pregnant women and their unborn babies is required. The GAIA project was formed in response to the call of the World Health Organization for a globally concerted approach to actively monitor the safety of vaccines and immunization in pregnancy programs. GAIA aims to improve the quality of outcome data from clinical vaccine trials in pregnant women with a specific focus on the needs and requirements for safety monitoring in LMIC. In the first year of the project, a large and functional network of experts was created. The first outputs include a guidance document for clinical trials of immunization in pregnancy, a basic data collection guide, ten case definitions of key obstetric and neonatal health outcomes, an ontology of key terms and a map of pertinent disease codes. The GAIA Network is designed as an open and growing forum for professionals sharing the GAIA vision and aim. Based on the initial achievements, tools and services are developed to support investigators and strengthen immunization in pregnancy programs with specific focus on LMIC.
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Salud Global , Inmunización/efectos adversos , Embarazo , Vacunas/efectos adversos , Ensayos Clínicos como Asunto , Femenino , Humanos , Vacunas/administración & dosificación , Organización Mundial de la SaludRESUMEN
PROBLEM/CONDITION: Vaccines are usually administered to healthy persons who have substantial expectations for the safety of the vaccines. Adverse events after vaccinations occur but are generally rare. Some adverse events are unlikely to be detected in prelicensure clinical trials because of their low frequency, the limited numbers of enrolled subjects, and other study limitations. Therefore, postmarketing monitoring of adverse events after vaccinations is essential. The cornerstone of monitoring safety is review and analysis of spontaneously reported adverse events. REPORTING PERIOD COVERED: This report summarizes the adverse events reported to the Vaccine Adverse Event Reporting System (VAERS) from January 1, 1991, through December 31, 2001. DESCRIPTION OF SYSTEMS: VAERS was established in 1990 under the joint administration of CDC and the Food and Drug Administration (FDA) to accept reports of suspected adverse events after administration of any vaccine licensed in the United States. VAERS is a passive surveillance system: reports of events are voluntarily submitted by those who experience them, their caregivers, or others. Passive surveillance systems (e.g., VAERS) are subject to multiple limitations, including underreporting, reporting of temporal associations or unconfirmed diagnoses, and lack of denominator data and unbiased comparison groups. Because of these limitations, determining causal associations between vaccines and adverse events from VAERS reports is usually not possible. Vaccine safety concerns identified through adverse event monitoring nearly always require confirmation using an epidemiologic or other (e.g., laboratory) study. Reports may be submitted by anyone suspecting that an adverse event might have been caused by vaccination and are usually submitted by mail or fax. A web-based electronic reporting system has recently become available. Information from the reports is entered into the VAERS database, and new reports are analyzed weekly. VAERS data stripped of personal identifiers can be reviewed by the public by accessing http://www.vaers.org. The objectives of VAERS are to 1) detect new, unusual, or rare vaccine adverse events; 2) monitor increases in known adverse events; 3) determine patient risk factors for particular types of adverse events; 4) identify vaccine lots with increased numbers or types of reported adverse events; and 5) assess the safety of newly licensed vaccines. RESULTS: During 1991-2001, VAERS received 128,717 reports, whereas >1.9 billion net doses of human vaccines were distributed. The overall dose-based reporting rate for the 27 frequently reported vaccine types was 11.4 reports per 100,000 net doses distributed. The proportions of reports in the age groups <1 year, 1-6 years, 7-17 years, 18-64 years, and >/= years were 18.1%, 26.7%, 8.0%, 32.6%, and 4.9%, respectively. In all of the adult age groups, a predominance among the number of women reporting was observed, but the difference in sex was minimal among children. Overall, the most commonly reported adverse event was fever, which appeared in 25.8% of all reports, followed by injection-site hypersensitivity (15.8%), rash (unspecified) (11.0%), injection-site edema (10.8%), and vasodilatation (10.8%). A total of 14.2% of all reports described serious adverse events, which by regulatory definition include death, life-threatening illness, hospitalization or prolongation of hospitalization, or permanent disability. Examples of the uses of VAERS data for vaccine safety surveillance are included in this report. INTERPRETATION: As a national public health surveillance system, VAERS is a key component in ensuring the safety of vaccines. VAERS data are used by CDC, FDA, and other organizations to monitor and study vaccine safety. CDC and FDA use VAERS data to respond to public inquiries regarding vaccine safety, and both organizations have published and presented vaccine safety studies based on VAERS data. VAERS data are also used by the Advisory Committee on Immunization Practices and the Vaccine and Related Biological Products Advisory Committee to evaluate possible adverse events after vaccinations and to develop recommendations for precautions and contraindications to vaccinations. Reviews of VAERS reports and the studies based on VAERS reports during 1991-2001 have demonstrated that vaccines are usually safe and that serious adverse events occur but are rare. PUBLIC HEALTH ACTIONS: Through continued reporting of adverse events after vaccination to VAERS by health-care providers, public health professionals, and the public and monitoring of reported events by the VAERS working group, the public health system will continue to be able to detect rare but potentially serious consequences of vaccination. This knowledge facilitates improvement in the safety of vaccines and the vaccination process.
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Vacunas/efectos adversos , Adolescente , Adulto , Sistemas de Registro de Reacción Adversa a Medicamentos , Anciano , Niño , Preescolar , Bases de Datos Factuales , Femenino , Síndrome de Guillain-Barré/epidemiología , Síndrome de Guillain-Barré/etiología , Humanos , Lactante , Intususcepción/epidemiología , Intususcepción/etiología , Masculino , Persona de Mediana Edad , Estados Unidos/epidemiologíaRESUMEN
The Vaccine Adverse Event Reporting System (VAERS) is administered by the Food and Drug Administration and CDC and is a key component of postlicensure vaccine safety surveillance. Its primary function is to detect early warning signals and generate hypotheses about possible new vaccine adverse events or changes in frequency of known ones. VAERS is a passive surveillance system that relies on physicians and others to voluntarily submit reports of illness after vaccination. Manufacturers are required to report all adverse events of which they become aware. There are a number of well-described limitations of such reporting systems. These include, for example, variability in report quality, biased reporting, underreporting and the inability to determine whether a vaccine caused the adverse event in any individual report. Strengths of VAERS are that it is national in scope and timely. The information in VAERS reports is not necessarily complete nor is it verified systematically. Reports are classified as serious or nonserious based on regulatory criteria. Reports are coded by VAERS in a uniform way with a limited number of terms using a terminology called COSTART. Coding is useful for search purposes but is necessarily imprecise. VAERS is useful in detecting adverse events related to vaccines and most recently was used for enhanced reporting of adverse events in the national smallpox immunization campaign. VAERS data have always been publicly available. However, it is essential for users of VAERS data to be fully aware of the strengths and weaknesses of the system. VAERS data contain strong biases. Incidence rates and relative risks of specific adverse events cannot be calculated. Statistical significance tests and confidence intervals should be used with great caution and not routinely. Signals detected in VAERS should be subjected to further clinical and descriptive epidemiologic analysis. Confirmation in a controlled study is usually required. An understanding of the system's defined objectives and inherent drawbacks is vital to the effective use of VAERS data in vaccine safety investigations.
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Seguridad de Productos para el Consumidor , Vacunación/efectos adversos , Vacunas/administración & dosificación , Vacunas/efectos adversos , Sistemas de Registro de Reacción Adversa a Medicamentos , Centers for Disease Control and Prevention, U.S. , Preescolar , Femenino , Humanos , Lactante , Masculino , Medición de Riesgo , Estadística como Asunto , Estados Unidos , Vacunación/métodosRESUMEN
Recent papers in Expert Opinion on Drug Safety arrived at different conclusions about the safety of hepatitis B vaccines. In one of these, review of the epidemiological literature failed to confirm the serious allegations raised with respect to vaccination. In the other, review of case reports and the authors' analytical method suggested serious adverse events are associated with the vaccine. In particular, they suggested a strong relationship with multiple sclerosis, the adverse event that has been the focus of several epidemiological investigations and has been found not to be related to vaccination. The method, using data from reported cases, attempted to compute relative and attributable risks using adult Td vaccine as a comparator. The authors made errors in assumptions about the data, including inappropriate use of controls and inappropriate application of epidemiology, rendering the conclusions invalid. Passive reporting data should be analysed with care and used only for hypothesis generation - anything more requires robust epidemiological study.