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Currently, the number of vehicles in circulation continues to increase steadily, leading to a parallel increase in vehicular accidents. Among the many causes of these accidents, human factors such as driver drowsiness play a fundamental role. In this context, one solution to address the challenge of drowsiness detection is to anticipate drowsiness by alerting drivers in a timely and effective manner. Thus, this paper presents a Convolutional Neural Network (CNN)-based approach for drowsiness detection by analyzing the eye region and Mouth Aspect Ratio (MAR) for yawning detection. As part of this approach, endpoint delineation is optimized for extraction of the region of interest (ROI) around the eyes. An NVIDIA Jetson Nano-based device and near-infrared (NIR) camera are used for real-time applications. A Driver Drowsiness Artificial Intelligence (DD-AI) architecture is proposed for the eye state detection procedure. In a performance analysis, the results of the proposed approach were compared with architectures based on InceptionV3, VGG16, and ResNet50V2. Night-Time Yawning–Microsleep–Eyeblink–Driver Distraction (NITYMED) was used for training, validation, and testing of the architectures. The proposed DD-AI network achieved an accuracy of 99.88% with the NITYMED test data, proving superior to the other networks. In the hardware implementation, tests were conducted in a real environment, resulting in 96.55% and 14 fps on average for the DD-AI network, thereby confirming its superior performance.

A restorative process, where the nonmetallic fraction from e-waste printed circuit boards is reused as a raw material for the conformation of a new polymer matrix composite with increased properties favoring its industrial applications, is proposed with a zero residues approach. Low density polyethylene pellets and nonmetallic fraction particles were mixed, and due to the generation of static electricity during the mixing process, the nonmetallic particles became attached to the polyethylene pellets; the blended material was fed into a screw extruder, producing filaments of the new composite. Mechanical properties increased as the particles content increased, presenting an ultimate tensile strength going from 20 for the raw low-density polyethylene to more than 60 MPa, and a yield strength that goes from 10 to 50 MPa on the composite with 6.0 wt.% particles. Also, the flammability of the composite improved, reducing its linear burning rate and increasing the time between detachment of two consecutive drops. Nonmetallic fraction particles were oriented in the extrusion direction and had a good adhesion with the polyethylene matrix. These composites can be employed for the production of prototypes using additive manufacture.

Electronic waste stream grows day by day; printed circuit boards are a kind of solid waste that accounts for 6% of electronic waste. When these are discarded, they can cause soil, water, and air contamination; however, if recycled, these can be considered as a secondary source of metals. Physical comminution of printed circuit boards generates particles with sizes smaller than 250 µm, which are typically not included in the recycling process because they are considered as dust and unvaluable; nevertheless, precious and base metals can be found in these particles. The concentration of metals like silver, among others, from these particles can be achieved by reverse froth flotation in a flotation column followed by magnetic separation of the tails products. A mass balance of the flotation column feed, concentrate, and tails indicates that using a pulp modified with 5 ppm methyl isobutyl carbinol plus 5 g/ton oleic acid (both biodegradable reagents), the concentration of the products improved, resulting in recoveries of 86.13 and 13.87% in the concentrate and tails zones, respectively, with a grade of 74.4% in the tails flow. Magnetic separation of the tails product increases slightly the concentration of silver, reaching a silver grade of 74.5%, a recovery amount similar to those obtained employing complex and environmentally unfriendly processes.

La situación de confinamiento ha expuesto a los ciudadanos a una gran cantidad de información sobre el COVID-19, tanto oficial como extraoficial, con diferentes fuentes y distintos grados de confiabilidad. La incertidumbre conduce a una mayor búsqueda de información y de ello depende la salud de los ciudadanos. En el presente estudio se explorarán los procesos de mediación que intervienen en la relación que produce la confianza en actores vinculados con la pandemia de COVID-19, así como el consumo de medios sobre las medidas de prevención que toma la ciudadanía para su cuidado. El análisis se hace a partir de una muestra representativa de 1211 ciudadanos mexicanos. Entre los principales resultados se encuentra que los ciudadanos están muy informados sobre el COVID-19, presentan un elevado nivel de consumo de medios y tienen un fuerte grado de confianza institucional, particularmente en los organismos no gubernamentales. En lo que respecta a las medidas de prevención, estas se asocian con la confianza que tienen en los empleados del sector salud. Asimismo, en cuanto a la aceptación de planteamientos tanto falsos como verdaderos, se encuentra que estos se relacionan con la toma de medidas de prevención para mitigar los efectos de la pandemia.

Notable efforts have been devoted to the development of biomechanical models of the spine, so the development of a motion system to control the spine becomes expressively relevant. This paper presents a fuzzy controller to manipulate the movement of a 3D robotic mechanism of the lumbar spine, which is driven by tendons. The controller was implemented in Matlab/Simulink R2023a software, MathWorks (Brazil), considering mathematical modeling based on the Lagrangian methodology for simulating the behavior of the lumbar spine dynamic movement. The fuzzy controller was implemented to perform movements of two joints of the 3D robotic mechanism, which consists of five vertebrae grouped into two sets, G1 and G2. The mechanism’s movements are carried out by four servomotors which are driven by readings from two sensors. For control, the linguistic variables of position, velocity and acceleration were used as controller inputs and the torque variables were used for the controller output. The experimental tests were carried out by running the fuzzy controller directly on the 3D physical model (external to the simulation environment) to represent flexion and extension movements analogous to human movements.

Synthetic aperture radar (SAR) raw data do not have a direct application; therefore, SAR raw signal processing algorithms are used to generate images that are used for various required applications. Currently, there are several algorithms focusing SAR raw data such as the range-Doppler algorithm, Chirp Scaling algorithm, and Omega-k algorithm, with these algorithms being the most used and traditional in SAR raw signal processing. The most prominent algorithm that operates in the frequency domain for focusing SAR raw data obtained by a synthetic aperture radar with large synthetic apertures is the Omega-k algorithm, which operates in the two-dimensional frequency domain; therefore, in this paper, we used the Omega-k algorithm to produce SAR images and modify the Omega-k algorithm by adding the Doppler factor to improve the accuracy of SAR raw data processing obtained by the continuous wave and pulsed frequency modulated linear frequency modulated radar system from the surfaces of interest. On the other hand, for the case of unmanned aerial vehicle-borne linear frequency modulated continuous wave (LFM-CW) SAR systems, we added motion compensation to the modified Omega-k algorithm. Finally, the testing and validation of the developed Omega-k algorithm used simulated and real SAR raw data for both pulsed synthetic aperture and continuous wave radars. The real SAR raw data used for the validation of the modified Omega-k algorithm were the raw data obtained by the micro advanced synthetic aperture radar (MicroASAR) system, which is an LFM-CW synthetic aperture radar installed on board an unmanned aerial system and the raw data obtained by European remote sensing (ERS-2) satellite with a synthetic aperture radar installed.

Evaluation of the effects of feeding NutraGen supplement (NutraGen, NTG; Phibro Animal Health, Teaneck, NJ, USA) on growth performance, energetic efficiency, carcass characteristcs, and characteristics of digestion in calf-fed Holstein steers fed a conventional growing-finishing diet. Trial 1 evaluated growth performance, dietary energetics and carcass characteristics. Two hundred Holstein steer calves (134 ± 5 kg) were blocked by initial body weight (BW) and randomly assigned to 40 pens (5 steers/pen). Dietary treatments consisted of a steam-flaked corn-based growing-finishing diet supplemented with 0, 0.2, 0.4, or 0.6% NTG (DM basis). In trial 2, four Holstein steers (170 ±6 kg) with cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square experiment to evaluate digestibility and ruminal characteristics using the treatments from trial 1. Compared to non-supplemented cattle, NTG increased BW (2.0%, P = 0.02) and tended to increase ADG (3.6%, P = 0.07) during the initial 56 d period. However, there were no treatment effects on overall growth performance and efficiency of dietary energy utilization after the first 56 days (P > 0.10). Supplementation of NTG increased (linear effect; P ≤ 0.03) longissimus muscle area and kidney, pelvic, and heart fat. There was no effect (P ≥ 0.05) of NTG supplementation on other carcass characteristics, liver abscess incidence, or liver abscess scars. Supplementation decreased the molar proportion of ruminal propionate (P = 0.05) and tended to increase acetate:propionate molar ratio (P = 0.09). However, there was no effect of NTG supplementation on ruminal and total tract diet digestion. NTG increased performance of Holstein steers during the first 56 d on feed in the feedlot. In addition, the steers had an increase in KPH fat and LM area, indicating that the additive induced change in metabolism of the steers.

Este artículo presenta el análisis de la historia de desarrollo de una empresa, ahora internacional, en donde sus creadores supieron aprovechar la situación del entorno, así como la red de relaciones que establecieron para lograr la innovación, el desarrollo de nuevos productos y a la apertura de mercados. El objetivo de este trabajo es analizar la importancia que tiene el capital relacional para lograr un impacto positivo en el desempeño de la empresa y su desarrollo y crecimiento. El estudio se realiza con base en el concepto de capital relacional desde tres componentes: el humano, el objetivo y el colectivo.

Drowsiness detection is an important task in road safety and other areas that require sustained attention. In this article, an approach to detect drowsiness in drivers is presented, focusing on the eye region, since eye fatigue is one of the first symptoms of drowsiness. The method used for the extraction of the eye region is Mediapipe, chosen for its high accuracy and robustness. Three neural networks were analyzed based on InceptionV3, VGG16 and ResNet50V2, which implement deep learning. The database used is NITYMED, which contains videos of drivers with different levels of drowsiness. The three networks were evaluated in terms of accuracy, precision and recall in detecting drowsiness in the eye region. The results of the study show that all three convolutional neural networks have high accuracy in detecting drowsiness in the eye region. In particular, the Resnet50V2 network achieved the highest accuracy, with a rate of 99.71% on average. For better visualization of the data, the Grad-CAM technique is used, with which we obtain a better understanding of the performance of the algorithms in the classification process.

Tomando en cuenta el proceso electoral 2017-2018, se utilizó una base de datos de 1 957 760 tuits para conocer cómo caracterizaron los usuarios de Twitter las posturas ideológicas de los candidatos y de la candidata a la Presidencia de México. Se observó una construcción altamente polarizada de la elección en torno a dos constructos ideológicos sobresimplificados: el populismo y el neoliberalismo. En general, los usuarios utilizaron encuadres negativos para describir las posiciones ideológicas de los candidatos que fueron mencionados en sus tuits. / Taking the 2017-2018 electoral process into consideration, a database that comprised 1 957 760 tweets was resorted to in order to find out how twitter users characterized the presidential candidates’ ideological postures. A highly polarized construction of the election around two oversimplified ideological constructs: populism and neoliberalism. By and large, twitter users used negative framings to describe the ideological stances of the candidates mentioned in their tweets.

La reforma electoral de 2014 le otorgó al Instituto Nacional Electoral (INE) la rectoría en la organización de los comicios locales en México, lo cual suscitó dudas respecto a su relación con los organismos públicos locales electorales (OPLES). Por ello, el presente trabajo tiene como objetivo caracterizar la coordinación entre el INE y el Instituto Estatal Electoral de Hidalgo (IEEH) durante la organización de las elecciones de la entidad en 2015-2016. Al sistematizar las experiencias de 39 servidores electorales mediante grupos de enfoque, se percibieron deficiencias importantes en la profesionalización de los funcionarios locales. Por lo anterior, el INE tuvo que aportar la experiencia de su personal y hacer uso de su autoridad para garantizar el apego a la normatividad durante el proceso. /

In this article, a combination of rectangular loop array and slot radiator for multiband applications is presented. The antenna is configured by arranging, concentrically, a set of rectangular loop radiators excited by electromagnetic coupling provided by a dumbbell slot. The size of the loops is calculated to obtain the desired resonant frequencies, which are almost independent of the adjacent rings. The exciting slot is designed to operate in a wideband frequency range to cover the upper desired resonance. In addition, to obtain directive radiation patterns, a reflector shaped like a box is introduced, giving a stable gain, radiation pattern shape, and port matching at the selected frequencies. The configuration presents great results, since to the authors’ knowledge, even a similar configuration given in the open literature presents some disadvantages compared to this one; moreover, not just any structure can be employed as the resonating elements, obtaining multiband behavior at the same time.

El estudio del comportamiento electoral, en lo que se refiere a la manera en cómo los ciudadanos toman la decisión de por quién votar en una democracia, es un tema que adquiere relevancia en México a partir de las elecciones de 1988, derivado del surgimiento de fuerzas políticas que pueden competir electoralmente contra el partido hegemónico: el Partido Revolucionario Institucional (PRI). Debido a lo reciente de este acontecimiento, muchas de las investigaciones realizadas en el país sobre este campo de estudio corresponden a esfuerzos aislados y poco sistematizados. Por esta razón, el objetivo del presente trabajo es sistematizar, mediante una revisión documental, el conocimiento disponible en México sobre el comportamiento electoral de los votantes mexicanos. De esta revisión se concluye que los estudios electorales en México han buscado adaptar a la realidad del país los constructos y las teorías creadas y probadas en Estados Unidos. Esta adaptación ha resultado positiva la mayoría de las veces y hoy existen instituciones y asociaciones académicas que han consolidado este campo de estudio. / The study of electoral behavior regarding how citizens decide who to vote for in a democracy has become important in Mexico since the 1988 elections. That is because in that year, political forces emerged that were able to compete at the polls with the Institutional Revolutionary Party (PRI), until then hegemonic. Since this is still very recent, many of the initial research projects in this field in Mexico have been isolated efforts that were not very systematic. For this reason, the aim of this article is to systematize the information available in Mexico about voter behavior through a review of the literature. This review concludes that electoral studies in Mexico have attempted to adapt to Mexico’s situation constructs and theories created and tested in the United States. This adaptation has been positive in most cases, and today institutions and academic institutions exist that have consolidated this field of study.

La vigencia de la división del trabajo imperante entre el norte y el sur, bajo el actual escenario de globalización económica, esta siendo modificada, por la a nueva tendencia en la que cualquier producto, (sea materia prima, manufacturado o servicio) puede ser producido en muchos países y regiones gracias en primer lugar al descenso en los costos de transporte, de telecomunicaciones, laborales, ambientales, que configuran unas ventajas de localización; pero además, a que luego del fracaso de la OMC desde la Ronda del Milenio hasta la de Doha y el fallido intento de la construcción de la Zona de Libre Comercio de las Américas (ALCA), la estrategia comercial de los EUA se ha centrado en impulsar acuerdos bilaterales de nueva generación TLC cuyo objetivo es lograr avanzar en una marco normativo que le garantice trato nacional y no discriminatorio al capital productivo extranjero (inversión extranjera), la estandarización de las normas técnicas, fitosanitarias, la defensa de los derechos de propiedad, entre otras.____________________ABSTRACT:The work division that exists between North and South, in this stage of economic globalization, it’s being modified by the new world tendency in which any product (raw materials, manufactured products or services) can be produced in many countries and regions, thanks to: in first place, the lowering of transportation , telecommunications, working and environmental costs, that create localization advantages; in second place, the breakdown of the WTO since the Millennium Round to Doha Round and the failure FTTA has made that the USA commercial strategy focus on Bilateral Agreements of the new generation such as the FTA, which proposes to advance in legal issues that guaranties not to discriminate the foreign investment, the standardization of technique and sanitary and phytosanitary measures and the intellectual property rights defence, among others.

La pérdida de valores es uno de los principales desencadenantes de conductas negativas en niñas, niños y jóvenes. Este fenómeno se atribuye en parte, a que valores sociales primordiales no se enseñan ni promueven en la familia, la escuela ni en el medio donde se desenvuelven estas personas. De ahí el interés de analizar el potencial que tiene en la educación básica la educación física y el deporte, como medios para apoyar y promover el desarrollo de valores sociales positivos; además, de que su presencia en el sistema educativo nacional contribuye al desarrollo del carácter, la personalidad, y la forma de pensar y actuar la persona. El artículo propone que los componentes del Programa de Educación Física permiten la enseñanza y el fomento de valores como la tolerancia y la identidad, entre otros. Se concluye que la educación física, por medio de las actividades lúdicas, recreativas y deportivas proporciona espacios para fomentar hábitos y valores que fortalecen la voluntad para alcanzar una mejor salud física, equilibrio psicosocial y, por consiguiente, una adecuada calidad de vida.

Objetivos: Evaluar la sensibilidad, especificidad y valores predictivos de la prueba rapida basada en la deteccion de la pLDH (OptiMALR) kit individual para el diagnostico de malaria en areas endemicas del Peru. Materiales y metodos: Estudio transversal realizado con pacientes febriles atendidos en centros de salud de la selva norte del Peru (San Martin y Loreto), de abril a diciembre de 2001. A cada paciente se le realizo la gota gruesa, la prueba OptiMALR y densidad parasitaria en forma ciega, por personal local capacitado y luego en el Laboratorio Nacional de Referencia de Malaria. Se calculo la sensibilidad (S), especificidad (E), valor predictivo positivo (VPP) y valor predictivo negativo(VPN) de la prueba OptiMALR en relacion a la gota gruesa para el diagnostico de malaria global y segun especie (P.falciparum y P.vivax). Resultados: Se incluyeron 346 muestras, 170 positivas. La prueba OptiMALR tuvo niveles de S=95,7%, E=97,1%, VPP=97,7%, VPN=95,3% independientemente de la especie. Para P.falciparum tuvo S=90,5%, E=97,3%, VPP=67,9 y VPN=99.4%; en tanto que para P.vivax S=92,0%, E=99,0%, VPP=98,7% y VPN=93,5%. Las sensibilidades estratificadas por parasitemia fueron 97,0% (5000 parasitos/¥ìL), 99% (100-5000 p/¥ìL) y 50% (

We construct a uniform in time asymptotic behavior, describing the interaction of two isothermal shock waves with the same direction of motion. The main result is that any smooth regularization of the problem implies the realization of the stable scenario of interaction. In particular, the rarefaction wave appearance is described.

By introducing a natural reducibility definition for zero curvature equations, we give a Floquet representation for such systems and show applications to the reducibility problem for quasiperiodic 2-dimensional linear systems and to fiberwise linear dynamical systems on trivial vector bundles.

A proposed technique for size reduction of a conventional inverted-F antenna (IFA) and a planar inverted-F antenna (PIFA) by employing a reactive load generated by a short-circuited stub is presented. The reduction factor of both antennas is around 30%, and the main parameters of the devices are preserved, including a fractional bandwidth of 4% and a gain of −2 dB. Both antennas operate around 1.5 GHz.

Este trabajo intenta mostrar la pervivencia de Lucrecio en unos pocos momentos de la tradición: en el reemplazo de la religión grecolatina por la cristiana, en la renovada convivencia de ambas creencias a partir del Humanismo (con su repercusión en la pintura del Renacimiento), y su reaparición, explí­cita o silente, en la producción de Jorge Luis Borges

Las distintas actividades sociales de relevancia se cumplen a través de organizaciones muy variadas (culturales, de la salud, de la educación, económicas, religiosas, etc. y también las del Estado), con distinta naturaleza jurídica, diversidad de intereses predominantes y formas de funcionar. Esto hoy está claramente desarrollado (se habla de la “era de la organización”), pero siempre hubo organizaciones, división de tareas y actuación de “directores o gerentes”. La organización tiene una dimensión general de validez para todo tipo de empresa, en una visión especialmente interna, referente a aquella división.

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This article presents a symmetrical reduced-size eight-element MIMO antenna array with high electromagnetic isolation among radiators. The array utilizes easy-to-build techniques to cover the n77 and n78 new radio (NR) bands. It is based on an octagonal double-negative metamaterial split-ring resonator (SRR), which enables a size reduction of over 50% for the radiators compared to a conventional disc monopole antenna by increasing the slow-wave factor. Additionally, due to the extreme proximity between the radiating elements in the array, the modal significance ( MS ) method was employed to identify which propagation modes had the most impact on the electromagnetic coupling among elements. This approach aimed to mitigate their effect by using an electromagnetic barrier, thereby enhancing electromagnetic isolation. The electromagnetic barriers, implemented with strip lines, achieved isolation values exceeding 20 dB for adjacent elements (<0.023 λ) and approaching 40 dB for opposite ones (<0.23 λ) after analyzing the surface current distribution by the MS method. The elements are arranged in axial symmetry, forming an octagon with each antenna port located on a side. The array occupies an area of 0.32 λ 2 at 3.5 GHz, significantly smaller than previously published works. It exhibits excellent performance for MIMO applications, demonstrating an envelope correlation coefficient ( ECC ) below 0.0001, a total active reflection coefficient ( TARC ) lower than -10 dB for various incoming signals with random phases, and a diversity gain ( DG ) close to 20 dB.

Background: Infants less than 6 months of age are at high risk for influenza disease and influenza-related complications, but no vaccine is licensed for this population., Methods: A double-blind, randomized, placebo-controlled trial was conducted in 1375 healthy US infants 6 to 12 weeks of age. Subjects received 2 doses of trivalent inactivated influenza vaccine (TIV, Fluzone, sanofi pasteur; N = 915) or placebo (N = 460) 1 month apart in combination with indicated concomitant vaccines. Solicited adverse events were collected for 7 days following vaccination, and unsolicited adverse events for 28 days. Hemagglutination-inhibition antibodies to all 3 vaccine strains were measured following the second TIV/placebo dose., Results: No significant differences were seen between TIV and placebo groups for any safety outcome. Fever > or =38 degrees C within 3 days of vaccination was seen in 11.2% versus 11.7% of TIV versus placebo recipients. Serious adverse events within 28 days were reported in 1.9% of TIV and 1.5% of placebo recipients. Antibody responses to childhood vaccines were similar in both groups. Increased influenza-specific antibody responses in TIV recipients compared with placebo recipients were seen against all 3 strains in TIV recipients (P < 0.001), with better responses to influenza A strains noted. Reciprocal geometrical mean titer to H1N1, H3N2, and B were 33, 95, and 11 in TIV recipients versus 7, 9, and 5 for placebo recipients. Over 90% of TIV recipients had antibody > or =1:40 for at least 1 vaccine strain and 49.6% for 2 strains, versus 16.4% and 0.9% in placebo-recipients., Conclusions: TIV administered to young infants beginning at 6 to 12 weeks of age is safe and immunogenic.

Background: Although children less than 6 months of age have the highest risk for hospitalization related to influenza infection, influenza vaccine is not approved for these children., Methods: In an open-label, off-season study, healthy 6 to 12 week and 6-month-old children received 2 doses of the 2004 to 2005 trivalent inactivated influenza vaccine (TIV) administered 1 month apart along with other routine pediatric vaccines. Safety was assessed by parental diaries (n = 393). Immunogenicity analyses (n = 293) were performed on sera obtained before vaccination and 1 month after the second dose of TIV. Outcomes included the frequencies of subjects with injection site and systemic reactions and seroprotection rates to TIV antigens., Results: Injection site reactions and fevers were generally mild and resolved within 3 days. Postvaccination seroprotection rates (titer > or = 1:40) in the 6- to 12-week-old and 6-month-old groups were 46% and 69% to A/New Caledonia (H1N1), 59% and 79% to A/Wyoming (H3N2), and 5% and 22% to B/Jiangsu (P < 0.001, all comparisons). For seronegative 6- to 12-week-olds whose mothers had not received TIV during pregnancy, postvaccination seroprotective titers to A/New Caledonia (H1N1) were achieved in 70% (38/54) and to A/Wyoming (H3N2) in 68% (23/34) of infants., Conclusions: TIV was well tolerated and safe when administered to children at both 6 to 12 weeks and 6 months of age. The antibody response was lower in the younger children, probably related to antibody suppression from passively acquired antibodies from mothers. In 6- to 12-week-olds without preexisting antibody, seroresponses to influenza A antigens approached those of 6-month-old children.

To improve immune responses to influenza vaccine, a trivalent inactivated vaccine containing 60 microg of the HA of each component (A/H3N2, A/H1N1, B) was compared to a licensed vaccine containing 15 microg of the HA of each. More local and systemic reactions were reported by subjects given the high dosage but only local pain and myalgias were significantly increased. The high dosage vaccine induced a higher frequency of serum antibody increases (> or =4-fold) in both hemagglutination-inhibiting (HAI) and neutralization tests for all three vaccine viruses in the total group as well as subjects vaccinated and those not vaccinated the previous year. Mean titers of antibody attained, the magnitude of antibody increases and the frequencies of persons with final HAI antibody titers > or =1:32, > or =1:64, and > or =1:128 were all greater for the high dosage group in both serologic tests, for all groups, and for all vaccine viruses. These increased immune responses should provide increased protection against influenza in the elderly.

This study assessed the safety and immunogenicity of a pediatric formulation of the 2003-2004 inactivated, trivalent, split virion influenza vaccine, administered in a 2-dose schedule in healthy children ages 6-36 months, of whom 94% had protective titers (> or =1/40) to at least 1 antigen. The 2003-2004 split virion influenza vaccine was safe and immunogenic in young children.

Healthy children aged < or =2 years have hospitalization rates during influenza periods 12 times those of older children and comparable to rates in the elderly population. In 2003, killed influenza vaccines were "recommended" for children with high-risk conditions and were "encouraged" for children aged 6-23 months. Studies involving several thousand children show that split-virus vaccines are safe and immunogenic in healthy children aged > or =6 months and in high-risk children. In children aged < or =9 years, 2 doses of vaccine are required initially to achieve maximum protection. Studies of children aged 6 months to 15 years show vaccine efficacies of 31%-91% against influenza A and 45% against influenza B. Among children attending day care, a reduction in the rate of acute otitis media of 32%-36% was demonstrated. Studies suggest that use of killed vaccines among children is cost-saving. In conclusion, the data show that killed influenza vaccines in children are safe, immunogenic, effective, and potentially cost-saving.