Enfermedad invasiva por Haemophilus influenzae: reporte de 14 casos luego de un año de iniciada la pandemia por COVID-19 / Invasive Haemophilus influenzae disease: A report of 14 cases one year after the COVID-19 pandemic outbreak

El Haemophilus influenzae (Hi) causa enfermedad invasiva (EI). Se distinguen cepas capsuladas, como el serotipo b (Hib), y cepas no tipificables (HNT). Al año de declarada la pandemia por COVID-19, observamos un aumento de casos. Se describen las características clínico-epidemiológicas de niños con EI por Hi internados en el hospital (julio 2021-julio 2022). Hubo 14 casos; 12 previamente sanos. Aislamientos: Hib (n = 6), Hi serotipo a (n = 2), HNT (n = 5), 1 no se tipificó. Mediana de edad: 8,5 meses (RIC 4-21). Manifestaciones: meningitis (n = 5), neumonía (n = 6), celulitis (n = 2), artritis (n = 1). Nueve presentaron vacunación incompleta para Hib. Observamos un incremento de EI por Hi de 2,5 veces respecto a años previos. Estos datos sugieren el resurgimiento de Hib por la caída de las coberturas de vacunación y porque otras cepas de Hi no b están en aumento.

Haemophilus influenzae (Hi) causes invasive disease. There are encapsulated strains, such as serotype b (Hib), and non-typeable strains (NTHi). One year after the outbreak of the COVID-19 pandemic, the number of cases increased. In this report we describe the clinical and epidemiological characteristics of children hospitalized with invasive Hi disease (July 2021-July 2022). There were 14 cases; 12 were previously healthy children. Isolations: Hib (n = 6), Hi serotype a (n = 2), NTHi (n = 5); 1 case was not typified. Median age: 8.5 months (IQR: 4­21). Manifestations: meningitis (n = 5), pneumonia (n = 6), cellulitis (n = 2), arthritis (n = 1). Incomplete Hib immunization was observed in 9 children. Invasive Hi disease increased 2.5 times from previous years. These data suggest the reemergence of Hib due to a decline in vaccination coverage and an increase in other non-b-type Hi serotypes.

Niveles de protección contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos / Levels of protection against Haemophilus influenzae type b in Cuban children, adolescents and adults

La concentración de los anticuerpos contra el polisacárido capsular polirribosilribitol fosfato del Haemophilus influenzae tipo b se considera un buen indicador serológico para evaluar protección contra la enfermedad invasiva. Existen pocos reportes que estudien la inmunidad serológica en Cuba. El objetivo general de este estudio fue determinar los niveles de protección séricos contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos, en una muestra de 575 individuos. Se cuantificó la concentración de IgG anti-polirribosilribitol fosfato de Haemophilus influenzae tipo b mediante un inmunoensayo enzimático estandarizado y validado en el laboratorio de inmunología del Centro Nacional de Genética Médica, La Habana, Cuba. Se determinaron las concentraciones medias geométricas de anticuerpos y los niveles de protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b. La concentración media geométrica de IgG anti-polirribosilribitol fosfato fue de 1,94 μg/mL (IC95 por ciento 1,80; 2,08) y fue mayor en el grupo de 16 a 22 años. El porcentaje con protección de larga duración fue mayor para el sexo femenino que para el masculino (82,2 por ciento vs 71,4 por ciento; p=0,0339) entre los que poseían inmunidad natural. El grupo de sujetos nacidos en el periodo en que se vacunó con la vacuna conjugada cubana QUIMI-HIB® presentó concentraciones medias geométricas superiores (2,75 μg/mL, IC95 por ciento 2,00; 3,79). El 99,1 por ciento de los participantes presentó protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b, el 19,8 por ciento a corto plazo y el 79,3 por ciento protección de larga duración. El inmunoensayo validado para la cuantificación de IgG anti-polirribosilribitol fosfato podría emplearse en estudios de seroprevalencia. En los sujetos estudiados, se encontró un predominio de elevadas concentraciones de IgG anti- polirribosilribitol fosfato del Haemophilus influenzae tipo b que confieren protección de larga duración(AU)

The levels of antibodies directed against the capsular polysaccharide polyribosylribitol phosphate of Haemophilus influenzae type b are considered a good serological indicator to assess the immunity against invasive disease. In Cuba, there are few reports that study serological immunity. The general objective was to determine serum protection levels against Haemophilus influenzae type b in Cuban children, adolescents and adults, in a sample of 575 Cuban individuals. The concentration of IgG against Haemophilus influenzae type b was quantified by means of an indirect ELISA standardized and validated in the immunology laboratory of the National Center of Medical Genetics, Havana, Cuba. The geometric mean concentration of IgG anti- polyribosylribitol phosphate and the levels of protection against invasive Haemophilus influenzae type b disease were determined. The geometric mean concentration of IgG anti- polyribosylribitol phosphate was 1.94 μg/mL (95percentCI 1.80;2.08) and the group from 16 to 22 years old presented the highest. Among those with natural immunity, the percentage with long-term protection was higher for females vs. males (82.2percent vs. 71.4percent; p=0.0339). The group of subjects born in the period in which they were vaccinated with the Cuban conjugate vaccine QUIMI-HIB® presented higher geometric mean concentration (2.75 μg/mL, CI95percent 2.00; 3.79). The 99.1percent of the participants had protection against invasive Haemophilus influenzae type b disease, 19.8percent short-term and 79.3percent long-term protection. The ELISA for the quantification of anti- Haemophilus influenzae type b IgG antibodies, developed and validated, could be used in seroprevalence studies. In the subjects studied, there was a predominance of high IgG anti- Haemophilus influenzae type b polyribosylribitol phosphate concentration values that confer long-term protection(AU)

Caracterización del polirribosilribitol fosfato por cromatografía de exclusión molecular de alta eficacia con detección ultravioleta / Characterization of polyribosylribitol phosphate by high efficiency size exclusion chromatography with ultraviolet detection

Haemophilus influenzae tipo b es un importante patógeno del hombre causante de varias de las enfermedades invasivas en niños menores de cinco años, contra el cual fueron autorizadas las vacunas glicoconjugadas a partir del polirribosilribitol fosfato. Quimi-Hib® es la primera y única vacuna contra este patógeno que utiliza el polisacárido obtenido por síntesis química. El Ingrediente Farmacéutico Activo es producido por el Centro de Ingeniería Genética y Biotecnología y se obtiene a partir de su conjugación al toxoide tetánico. En el presente reporte se hizo una caracterización del polirribosilribitol fosfato mediante la técnica de cromatografía de exclusión molecular de alta eficacia con detección ultravioleta a 215 nm. En el estudio se evaluaron tres lotes y se determinó el perfil de elución en una columna SuperdexTM 75 10/300 GL Increase con un porciento de pureza de 77,42 ± 8,97 y una masa molar promedio de 7.381 Da ± 210,93. La principal impureza presente en el polirribosilribitol fosfato es el dimetilsulfóxido, disolvente utilizado en la reacción de activación con el éster N-hidroxisuccinimidilo del ácido β-maleimidopropiónico. El polirribosilribitol fosfato se purificó por filtración con un Amicon Ultra-15 de 2.000 Da hasta una pureza de 99,1 por ciento y se conjugó al toxoide tetánico. El rendimiento de la reacción de conjugación con el polisacárido purificado fue de 30,0 por ciento 1,77 el cual no muestra diferencias significativas con el control que fue 33,7 por ciento ± 3,57 demostrándose que el dimetilsulfóxido no afecta el desempeño de la reacción de conjugación(AU)

Haemophilus influenzae type b is an important human pathogen causing some invasive diseases in children less than five years of age. Glycoconjugate vaccines based on polyribosylribitol phosphate have been licensed against this bacterium. Quimi-Hib® is the first and only vaccine against this pathogen using the chemically synthesized polysaccharide. The Active Pharmaceutical Ingredient is produced by the Center for Genetic Engineering and Biotechnology and is obtained from its conjugation to tetanus toxoid. In the present report a characterization of polyribosylribitol phosphate was performed by high performance molecular exclusion chromatography with ultraviolet detection at 215 nm. Three batches were evaluated in the study and the elution profile was determined on a SuperdexTM 75 10/300 GL Increase column with a purity percentage of 77.42 ± 8.97 and an average molecular weight of 7,381 Da ± 210.93. The main impurity present in polyribosylribitol phosphate was dimethylsulfoxide, the solvent used in the activation reaction with N-hydroxysuccinimidyl ester of β-maleimidopropionic acid. Polyribosylribitol phosphate was purified by filtration using a 2,000 Da cut-off Amicon Ultra-15 to a purity of 99.1 percent and conjugated to tetanus toxoid. The yield of the conjugation reaction with the purified polysaccharide was 30.0 percent ± 1.77 which shows no significant difference with the control which was 33.7 percent ± 3.57 demonstrating that dimethylsulfoxide does not affect the performance of the conjugation reaction(AU)

Co-administration of routine paediatric vaccines in England often deviates from the immunisation schedule.

Vaccine co-administration can facilitate the introduction of new vaccines in immunisation schedules and improve coverage. We analysed real life data to quantify the extent of routine paediatric vaccine co-administrations as recommended and as never recommended in the immunisation schedule in England, and assessed factors for recommended and never recommended vaccine co-administrations. Immunisation data for all scheduled routine paediatric vaccines between 2008 and 2018 was obtained from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We included 6'257'828 doses administered to 1'005'827 children. Twenty-one percent of vaccines were given separately, 79% were co-administered. Sixty-four percent of vaccines scheduled for co-administration were co-administered as recommended while 15% were administered separately. Among all vaccine co-administrations, 75% happened as recommended in the schedule, 4% were never recommended, while 21% deviated from the schedule. Vaccine co-administration according to the schedule varied greatly between vaccines. Forty-eight percent of English children received at least one of their vaccine co-administrations not as recommended in the immunisation schedule, with 19% of children receiving none of their co-administered vaccines as recommended. Late administration of one or more vaccines increased the odds for deviated co-administrations (OR 1.60) and strongly increased the odds for never recommended co-administrations (OR 5.34). Differences between genders, NHS regions, and IMD quintiles were statistically significant but small. Suboptimal co-administration rates for routine paediatric vaccines are a missed opportunity and should be optimised by concerted public health action.

Health care professionals' preference for a fully liquid, ready-to-use hexavalent vaccine in Spain.

Vaccination is an effective health intervention for the prevention of infectious diseases. This study aims to evaluate the response provided by nurses toward the use of ready-to-use (RTU) formulations of hexavalent vaccines and measures to prevent errors during the vaccination process. This observational, descriptive, cross-sectional study took place from March to May 2018. It included 201 interviews with nurses from health centers in Madrid (70), Murcia (59), and Andalusia (72), who had administered RTU vaccines in the last 12 months. Approximately 91.6% of nurses provided a positive feedback for the use of RTU vaccines. The most significant concerns experienced by nurses were during the preparation and administration of vaccines; 84.1% versus 18.9% of nurses felt that the risk of making mistakes was lower while using RTU vaccines compared with non-reconstituted (lyophilized) vaccines, and 74.1% versus 22.4% of nurses felt ease at preparing RTU vaccines compared with lyophilized vaccines. A total of 66.7% of nurses believed that there were risks associated with the preparation of lyophilized vaccines (administration risk [42.8%] and risk of needle injury [42.3%]). Risk percentages reduced to 4% and 9.5%, respectively, with the use of the RTU vaccines. Therefore, nurses adopted an average of seven steps to reduce the risk of errors. The average time saved during the administration of the vaccines was 1.1 min. In summary, nurses highlighted the need for administering vaccines using RTU formulations for ensuring the safety of the recipients, preventing errors, and saving time during the vaccination process.

Efficacy and Safety of Revaccination against Tetanus, Diphtheria, Haemophilus influenzae Type b and Hepatitis B Virus in a Prospective Cohort of Adult Recipients of Allogeneic Hematopoietic Stem Cell Transplantation.

Data on immunogenicity and safety of the recommended revaccination schedule against diphtheria, tetanus, poliomyelitis, pertussis, Haemophilus influenzae type b (Hib), and hepatitis B in adult allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients are limited. This prospective single-center cohort study (April 2014 to March 2018) included adult allo-HSCT recipients referred to a dedicated vaccinology consultation and vaccinated with the pediatric combined diphtheria, tetanus, acellular pertussis, hepatitis B virus, inactivated poliovirus, and Haemophilus influenzae type b (DTaP(±HB)-IPV-Hib) vaccine (3 doses 1 month apart, booster dose 1 year later). The proportion of responders to tetanus, diphtheria, Hib, and hepatitis B vaccine and geometric mean concentrations (GMCs) of antibodies were assessed before and up to 24 months after vaccination. A total of 106 patients were vaccinated at a median (interquartile range) time of 12.4 (10 to 18.4) months post-transplant. At 5.3 (4.8 to 6.6) and 23.1 (21.1 to 25.1) months after vaccine initiation, high and sustained rates of protective antibody titers were achieved for tetanus (97.8% [95% confidence interval (95% CI), 92.4% to 99.7%], n = 91/93 and 100% [95% CI, 92% to 100%], n = 44/44), diphtheria (94.6% [95% CI, 87.9% to 98.2%], n = 88/93 and 90.9% [95% CI, 78.3% to 97.5%], n = 40/44), Hib (96.6% [95% CI, 90.4% to 99.3%], n = 85/88 and 93% [95% CI, 80.9% to 98.5%], n = 40/43), and hepatitis B (83.5% [95% CI, 73.5% to 90.9%], n = 66/79 and 81.1% [95% CI, 64.8% to 92%], n = 30/37). Underlying disease, stem cell source, chronic graft-versus-host-disease, and extracorporeal photopheresis differentially influenced GMCs of tetanus, diphtheria, and hepatitis B antibodies after 3 doses but not in the long term (24 months). Six (5.7%) patients experienced mild side effects. The pediatric DTaP(±HB)-IPV-Hib vaccine was safe and effective in eliciting a sustained protective humoral response in adult allo-HSCT recipients. Hepatitis B revaccination might be optimized by using higher antigen doses.

Haemophilus influenzae type b capsular polysaccharide antibody levels in Japanese young patients with hematological malignancies and asplenia.

Individuals with immunosuppressive condition have a high risk of invasive Haemophilus influenzae type b (Hib) infection. In Japan, routine Hib vaccination program for children under 5 years old was introduced in December 2008. However, the national policy does not make provision for individuals aged ≥5 years who have medical conditions associated with a high risk of invasive Hib disease to receive Hib vaccine. We measured serum anti-polyribosylribitol phosphate specific (anti-PRP) antibodies to Hib in patients aged ≥5 years with hematological malignancies and asplenia and evaluated their levels of anti-PRP antibodies in post administration of Hib vaccine era. A total of 65 patients (48 with hematological malignancies, and 17 with asplenia) were included in this study, of which 84% had not received Hib vaccine. In addition, 95.4% had short-term protective levels of anti-PRP antibodies (defined as ≥0.15 µg/mL) and 41.5% had long-term protective levels of anti-PRP antibodies (defined as ≥1.0 µg/mL). Five patients had low anti-PRP antibody levels despite a history of Hib vaccination. Our results suggest that young patients with underlying diseases such as hematological malignancies and asplenia may be at risk of invasive Hib disease. Hence, we recommend they should receive Hib vaccines even if they are over the age limit for routine Hib vaccination program.

Epiglotitis por Haemophilus influenzae tipo b en la era de la vacunación: caso clínico pediátrico / Epiglottitis due to Haemophilus influenzae type b in the vaccination era: pediatric clinical case

La epiglotitis aguda infecciosa es infrecuente en la actualidad, debido a la vacunación contra su principal agente etiológico, el Haemophilus influenzae b. Se requiere alto índice de sospecha ante el cuadro clínico de dificultad respiratoria, estridor, disfonía y fiebre. Se presenta a un niño de 2 años, previamente sano, con esquema de vacunas completas, con dificultad respiratoria aguda y estridor laríngeo, en el que, al momento de realizar la intubación, se realizó el diagnóstico de epiglotitis aguda. Con hemocultivos positivos para Haemophilus influenzae b, cumplió 13 días de tratamiento con ceftriaxona, con hemocultivos de control y cultivo de líquido cefalorraquídeo negativo.

Acute infectious epiglottitis is infrequent at present due to vaccination for its main etiologic agent, Haemophilus influenzae b (Hib). It must be taken into account when we make a differential diagnosis in a child whose clinical symptoms are respiratory distress, stridor, dysphonia and fever. We report a 2-year-old child, previously healthy, whose vaccination calendar was complete, and whose clinical presentation included respiratory distress and stridor; at the moment of the intubation the laryngoscopy showed an acute epiglottitis. Blood cultures were taken, which were positive for Hib. He was treated with ceftriaxone during 13 days, and the control blood cultures and cerebrospinal fluid were negative.

Review of epiglottitis in the post Haemophilus influenzae type-b vaccine era.

BACKGROUND: This study reviewed the demographics, presentation, management, complications and outcomes of acute epiglottitis post Haemophilus influenzae type-b vaccine introduction in Australia. METHODS: Retrospective review of acute epiglottitis at four Victorian tertiary centres from 2011 to 2016 was conducted. Patient characteristics, presentation, investigations, management, complications and outcomes were recorded. Subgroup analysis aiming to identify risk factors for patients requiring acute airway management was performed. RESULTS: Eighty-seven adult and six paediatric cases were identified. The most frequent clinical findings in adults were sore throat (88.5%), dysphagia (71.3%), odynophagia (57.5%), dysphonia (56.3%) and fever (55.2%); 75.9% required intensive care unit admission. Airway compromise requiring intubation occurred in 27.6%, with 12.5% of these patients undergoing emergency surgical airways. Stridor, hypoxia, shortness of breath, odynophagia and lymphadenopathy were statistically more frequent amongst cases requiring airway intervention (P < 0.05). Cultures revealed mixed results with no aetiological pattern. H. influenzae type-b was never cultured. Amongst paediatric cases, fever, tachycardia and stridor were frequently observed and all were admitted to intensive care unit. Two of six required intubation and one underwent surgical intervention. There were no deaths, but one patient suffered a hypoxic brain injury. CONCLUSION: Modern epiglottitis is not the disease previously encountered by clinicians. With changing demographics and varying organisms, management is adapting to reflect this. Complications are rare, and symptomatology at presentation aids earlier recognition of patients who may require airway protection.

Progress in Vaccine-Preventable and Respiratory Infectious Diseases-First 10 Years of the CDC National Center for Immunization and Respiratory Diseases, 2006-2015.

The need for closer linkages between scientific and programmatic areas focused on addressing vaccine-preventable and acute respiratory infections led to establishment of the National Center for Immunization and Respiratory Diseases (NCIRD) at the Centers for Disease Control and Prevention. During its first 10 years (2006-2015), NCIRD worked with partners to improve preparedness and response to pandemic influenza and other emergent respiratory infections, provide an evidence base for addition of 7 newly recommended vaccines, and modernize vaccine distribution. Clinical tools were developed for improved conversations with parents, which helped sustain childhood immunization as a social norm. Coverage increased for vaccines to protect adolescents against pertussis, meningococcal meningitis, and human papillomavirus-associated cancers. NCIRD programs supported outbreak response for new respiratory pathogens and oversaw response of the Centers for Disease Control and Prevention to the 2009 influenza A(H1N1) pandemic. Other national public health institutes might also find closer linkages between epidemiology, laboratory, and immunization programs useful.

An ELISA method to estimate the mono ADP-ribosyltransferase activities: e.g in pertussis toxin and vaccines.

ADP-ribosyltransferase activities have been observed in many prokaryotic and eukaryotic species and viruses and are involved in many cellular processes, including cell signalling, DNA repair, gene regulation and apoptosis. In a number of bacterial toxins, mono ADP-ribosyltransferase is the main cause of host cell cytotoxicity. Several approaches have been used to analyse this biological system from measuring its enzyme products to its functions. By using a mono ADP-ribose binding protein we have now developed an ELISA method to estimate native pertussis toxin mono ADP-ribosyltransferase activity and its residual activities in pertussis vaccines as an example. This new approach is easy to perform and adaptable in most laboratories. In theory, this assay system is also very versatile and could measure the enzyme activity in other bacteria such as Cholera, Clostridium, E. coli, Diphtheria, Pertussis, Pseudomonas, Salmonella and Staphylococcus by just switching to their respective peptide substrates. Furthermore, this mono ADP-ribose binding protein could also be used for staining mono ADP-ribosyl products resolved on gels or membranes.

Surgical management of cervical spine deformity in chondrodysplasia punctata.

OBJECTIVE Chondrodysplasia punctata (CDP), a rare skeletal dysplasia, can lead to cervical spine instability and deformity. However, an optimal neurosurgical intervention has yet to be established. Thus, a retrospective study was conducted to assess the efficacy of various surgical interventions for children with CDP. METHODS The authors retrospectively reviewed 9 cases of CDP in which cervical decompression with or without posterior fusion was performed between April 2007 and May 2016. Patient demographics, preoperative clinical conditions, radiographic findings, surgical procedures, and the postoperative course were analyzed in detail. RESULTS A total of 12 operations were carried out in 9 patients (8 male, 1 female) during the study period. The patients' ages at the initial surgery ranged from 2 months to 2 years. Seven of the children had CDPX1, 1 had CDPX2, and 1 had tibia-metacarpal type CDP (CDP-TM). The lesion occurred at the craniovertebral junction (CVJ) in 7 cases and involved a subaxial deformity in 2 cases. The initial surgery was C-1 laminectomy with occipitocervical fusion (OCF) followed by halo external fixation in 5 cases, OCF alone in 1 case, and C-1 laminectomy alone in 3 cases. Three children required additional surgery. In one of these cases, a staged operation was required because the patient's head was too small to attach a halo ring at the time of the initial procedure (C-1 laminectomy). In another case, OCF was performed 11 months after C-1 laminectomy because of intramedullary signal change on serial MRI, although the child remained asymptomatic. In the third case, additional posterior fusion was performed 17 months after an initial laminectomy and OCF due to newly developed cervical dislocation caudal to the original fusion. This last patient required a third operation 9 months after the second because of deep wound infection. Surgery improved the motor function of all 7 children with CDPX1, but 3 children who had already suffered respiratory failure preoperatively required continued respiratory support. At the time of this report, 7 of the 9 children were alive and in stable condition. One child died due to restrictive respiratory insufficiency, and another died in an accident unrelated to CDP. CONCLUSIONS Surgical decompression with or without fusion for CVJ and subaxial cervical lesions in infants and toddlers with CDP generally saves lives and increases the likelihood of motor function recovery. However, in this case series the patients' preoperative condition had a strong effect on postoperative respiratory function. The surgery was not straightforward, and a second operation was required in some cases. Nevertheless, the findings indicate that early surgical intervention for CDP with cervical involvement is feasible, suggesting that the role of neurosurgery should be reevaluated.

Meningitis por Haemophilus influenzae b: ¿estamos ante una reemergencia? 24 años de experiencia en un hospital pediátrico / Haemophilus influenzae type B meningitis: Is there a re-emergence? 24 years of experience in a children's hospital

Introducción. Haemophilus influenzae b era la principal causa de meningitis bacteriana en menores de 5 años. Después de la introducción de la vacuna al calendario (1998), se observó un descenso significativo de la incidencia, pero, en los últimos años, hubo un aumento. Los objetivos de este estudio fueron describir las características y analizar la curva epidémica de los casos de meningitis por Haemophilus influenzae b (MHib) comparando los períodos pre- y posvacunación. Material y métodos. Estudio de series temporales. Se incluyeron todos los pacientes internados por MHib en el Hospital de Niños "R. Gutiérrez" (enero de 1992-mayo de 2016). Se compararon las tasas de hospitalización antes (prevacunación) y después (posvacunación) de la introducción de la vacuna. Se dividió la etapa posvacunación en tres períodos similares. Resultados. Fueron admitidos 85 pacientes con MHib (73,3% prevacunación). Las características clínicas y sociodemográficas de los casos en ambos períodos no mostraron diferencias. Prevacunación: 10,5 casos/año; y posvacunación: 0,7 casos/año. A partir de 2014, se observó un aumento. Tasa de letalidad: 4,8% (todos prevacunación). Datos posvacunación (n= 15): 40% del esquema primario completo, 40% del esquema atrasado para la edad. Reducción global de la tasa hospitalaria de MHib de 89,8% (IC 95%: -82,79-93,96%; p < 0,001) en el período posvacunación. Al analizar los diferentes períodos posvacunación, se observa una caída en la reducción a lo largo del tiempo. Conclusiones. Se observó una disminución muy importante de las hospitalizaciones por MHib pos introducción de la vacuna, pero, en los últimos años, se evidenció un aumento de estos casos sin modificaciones en las características de los pacientes.

Introduction. Haemophilus influenzae type B (Hib) used to be the main cause of bacterial meningitis in children younger than 5 years old. Following the introduction of the Hib vaccine in the immunization schedule (1998), its incidence reduced significantly but it has increased over the last years. The objectives of this study included describing the characteristics and analyzing the epidemic curve of Haemophilus influenzae type B (Hib) meningitis by comparing the pre- and postimmunization periods. Material and methods. Time-series study. All patients hospitalized with Hib meningitis at Hospital de Niños "R. Gutiérrez" (January 1992-May 2016). Hospitalization rates were compared before (pre-immunization) and after (post-immunization) the introduction of the Hib vaccine. The post-immunization period was divided into three similar periods. Results. Eighty-five patients with Hib meningitis were admitted (73.3% in the pre-immunization period). No differences were observed in relation to the clinical and sociodemographic characteristics of cases in both periods. Pre-immunization: 10.5 cases/year; postimmunization: 0.7 cases/year. As of 2014, the rate has increased. Lethality rate: 4.8% (all preimmunization). Post-immunization data (n= 15): 40% had completed their primary immunization schedule, 40% were delayed on the immunization schedule for their age. Overall reduction in the hospital rate of Hib meningitis by 89.8% (95% confidence interval: -82.79-93.96%, p < 0.001) in the post-immunization period. The analysis of the different post-immunization periods shows a decline in reduction over time. Conclusions. A very significant reduction in hospitalizations due to Hib meningitis was observed after the Hib vaccine was introduced; however, over the past years, the number of cases has increased although no changes have been observed in patient characteristics.

Budget impact analysis of vaccination against Haemophilus influenzae type b as a part of a Pentavalent vaccine in the childhood immunization schedule of Iran.

BACKGROUND: Health decision makers need to know the impact of the development of a new intervention on the public health and health care costs so that they can plan for economic and financial objectives. The aim of this study was to determine the budget impact of adding Haemophilus influenzae type b (Hib) as a part of a Pentavalent vaccine (Hib-HBV-DTP) to the national childhood immunization schedule of Iran. METHODS: An excel-based model was developed to determine the costs of including the Pentavalent vaccine in the national immunization program (NIP), comparing the present schedule with the previous one (including separate DTP and hepatitis B vaccines). The total annual costs included the cost of vaccination (the vaccine and syringe) and the cost of Hib treatment. The health outcome was the estimated annual cases of the diseases. The net budget impact was the difference in the total annual cost between the two schedules. Uncertainty about the vaccine effectiveness, vaccination coverage, cost of the vaccine, and cost of the diseases were handled through scenario analysis. RESULTS: The total cost of vaccination during 5 years was $18,060,463 in the previous program and $67,774,786 in the present program. Inclusion of the Pentavalent vaccine would increase the vaccination cost about $49 million, but would save approximately $6 million in the healthcare costs due to reduction of disease cases and treatment costs. The introduction of the Pentavalent vaccine resulted in a net increase in the healthcare budget expenditure across all scenarios from $43.4 million to $50.7 million. CONCLUSIONS: The results of this study showed that the inclusion of the Pentavalent vaccine in the NIP of Iran had a significant impact on the health care budget and increased the financial burden on the government. Budget impact of including Pentavalent vaccine in the national immunization schedule of Iranᅟ.

Immunogenicity and safety of a fully liquid aluminum phosphate adjuvanted Haemophilus influenzae type b PRP-CRM197-conjugate vaccine in healthy Japanese children: A phase III, randomized, observer-blind, multicenter, parallel-group study.

BACKGROUND: Broad use of monovalent Haemophilus influenzae type b (Hib) conjugate vaccines based on the capsular polysaccharide polyribosyl-ribitol phosphate (PRP), has significantly reduced invasive Hib disease burden in children worldwide, particularly in children aged <1year. In Japan, PRP conjugated to tetanus toxoid (PRP-T) vaccine has been widely used since the initiation of public funding programs followed by a routine vaccination designation in 2013. METHODS: We compared the immunogenicity and safety of PRP conjugated to a non-toxic diphtheria toxin mutant (PRP-CRM197) vaccine with the PRP-T vaccine when administered subcutaneously to healthy Japanese children in a phase III study. Additionally, we evaluated the immunogenicity and safety profiles of a diphtheria-tetanus acellular pertussis (DTaP) combination vaccine when concomitantly administered with either PRP-CRM197 or PRP-T vaccines. The primary endpoint was the "long-term seroprotection rate", defined as the group proportion with anti-PRP antibody titers ⩾1.0µg/mL, after the primary series. RESULTS: Long-term seroprotection rates were 99.3% in the PRP-CRM197 group and 95.6% in the PRP-T group. The intergroup difference (PRP-CRM197 group - PRP-T group) was 3.7% (95% confidence interval: 0.099-7.336), demonstrating that PRP-CRM197 vaccine was non-inferior to PRP-T vaccine (p<0.0001). Furthermore, the "short-term seroprotection rate" (anti-PRP antibody titer ⩾0.15µg/mL) before booster vaccination was higher in the PRP-CRM197 group than in PRP-T. Concomitant administration of PRP-CRM197 vaccine with DTaP vaccine showed no differences in terms of immunogenicity compared with concomitant vaccination with PRP-T vaccine and DTaP vaccine. Although CRM197 vaccine had higher local reactogenicity, overall, both Hib vaccines had acceptable safety and tolerability profiles. CONCLUSION: The immunogenicity of PRP-CRM197 vaccine administered subcutaneously as a three-dose primary series in children followed by a booster vaccination 1year after the primary series induced protective levels of Hib antibodies with no safety or tolerability concerns. CLINICAL TRIAL REGISTRY: Registered on ClinicalTrials.gov: NCT01379846.

Timing of Haemophilus influenzae type b vaccination after cardiac surgery.

BACKGROUND: The best time for vaccination in infants with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery is unclear, but it is important to prevent Haemophilus influenzae type b (Hib) infection in infants with CHD after CPB surgery. To identify the best time for Hib vaccination in infants with CHD after CPB surgery, we investigated the immunological status, and the efficacy and safety of Hib vaccination after CPB surgery. METHODS: Sixteen subjects who underwent surgical correction of ventricular septal defect with CPB were investigated. Immunological status and cytokines were analyzed before surgery, 2 months after surgery, and before Hib booster vaccination. Hib-specific IgG was also measured to evaluate the effectiveness of vaccination. RESULTS: Immunological status before and 2 months after surgery (e.g. whole blood cells and lymphocyte subset profile) was within the normal range and no subjects had hypercytokinemia. Additionally, all subjects who received Hib vaccination at 2-3 months after CPB surgery had effective serum Hib-specific IgG level for protection against Hib infection without any side-effects. CONCLUSIONS: CPB surgery does not influence acquired immunity and Hib vaccination may be immunologically safe to perform at 2 months after CPB surgery. Hib vaccination at 2-3 months after CPB surgery was effective in achieving immunization for infants with simple left-right shunt-type CHD.

Validation of infant immunization billing codes in administrative data.

Ontario has a single payer provincial health insurance program. Administrative data may provide a potentially robust source of information for post-marketing vaccine studies. Vaccine-specific immunization billing codes were introduced in 2011. Our objective was to validate Ontario's universal health care administrative datasets to assess infant immunization status. Electronic medical record data from the Electronic Medical Record Administrative data Linked Database (EMRALD) was used as the reference standard to calculate performance characteristics of the Ontario Health Insurance Plan (OHIP) database vaccine-specific and general immunization codes for 4 primary infant immunizations: diphtheria, tetanus, acellular pertussis, inactivated polio, Haemophilus influenzae type B (DTaP-IPV-Hib) combination vaccine, pneumococcal conjugate vaccine, measles, mumps, rubella (MMR) vaccine, and meningococcal conjugate serogroup C vaccine. OHIP billing claims had specificity ranging from 81% to 92%, sensitivity 70% to 83%, positive predictive value (PPV) 97% to 99%, and negative predictive value (NPV) 13% to 46% for identifying the various specific vaccines in administrative data. For cohorts vaccinated in the new code introduction phase, using both the vaccine-specific and general codes had higher sensitivity than the vaccine-specific codes alone. In conclusion, immunization billing claims from administrative data in Ontario had high specificity and PPV, moderate sensitivity, and low NPV. This study identifies some of the applications of utilizing administrative data for post-marketing vaccine studies. However, limitations of these data decrease their utility for measuring vaccine coverage and effectiveness. Therefore, the establishment of a comprehensive and linkable immunization registry should be a provincial priority.

Parent and provider perspectives on immunization: are providers overestimating parental concerns?

OBJECTIVES: Data are limited on whether providers understand parental attitudes to recommended childhood immunizations. We determined parental attitudes and assessed how accurately providers estimated parental opinions. METHODS: Survey of parents and providers (pediatricians, nurses, medical assistants) in randomly selected practices in Houston, Texas. Surveys assessed demographics, perceptions of immunization importance, safety and efficacy, and acceptability of vaccine delivery. Providers estimated parental responses. RESULTS: 401 parents (82% mothers, 12% fathers, 6% other) and 105 providers participated. Parents thought vaccines were important for health (median score 9.5; 0=not important, 10=extremely important) but also were concerned regarding vaccine safety and side effects (8.9 on 0-10 scale). 309 (77%) agreed that vaccines effectively prevent disease. Route of administration mattered to 147 (37%), who preferred injection (9.0) over oral (7.3) or intranasal (4.8) routes. Although parents would prefer three or fewer injections per visit, preventing more diseases (189 [47.6%]) was more important than number of injections (167 [42.3%]) when deciding the number of vaccines allowed per visit. White parents rated vaccines less important in preventing some illnesses than did non-white (P≤0.006 for meningitis, hepatitis, HPV, influenza and rotavirus) and rated number of injections per visit more important than number of diseases prevented (51.6% white versus 34.2% non-white; P 0.002). Providers underestimated parental attitudes toward vaccine importance (particularly influenza and HPV), and overestimated the proportion of parents who thought route of administration mattered (63%) and that number of injections per visit was the most important factor (76%) around parental vaccine decisions (P<0.001 for parent-provider mismatch). CONCLUSIONS: Most surveyed parents believe vaccines are important for child health and rate disease prevention higher than number of injections entailed. Providers underestimate the importance of some vaccines to parents and overestimate parental concerns regarding route of administration. Future research should focus on how this mismatch impacts parental vaccine decisions.

Post-licensure rapid immunization safety monitoring program (PRISM) data characterization.

BACKGROUND: The Post-Licensure Rapid Immunization Safety Monitoring (PRISM) program is the immunization safety monitoring component of FDA's Mini-Sentinel project, a program to actively monitor the safety of medical products using electronic health information. FDA sought to assess the surveillance capabilities of this large claims-based distributed database for vaccine safety surveillance by characterizing the underlying data. METHODS: We characterized data available on vaccine exposures in PRISM, estimated how much additional data was gained by matching with select state and local immunization registries, and compared vaccination coverage estimates based on PRISM data with other available data sources. We generated rates of computerized codes representing potential health outcomes relevant to vaccine safety monitoring. Standardized algorithms including ICD-9 codes, number of codes required, exclusion criteria and location of the encounter were used to obtain the background rates. RESULTS: The majority of the vaccines routinely administered to infants, children, adolescents and adults were well captured by claims data. Immunization registry data in up to seven states comprised between 5% and 9% of data for all vaccine categories with the exception of 10% for hepatitis B and 3% and 4% for rotavirus and zoster respectively. Vaccination coverage estimates based on PRISM's computerized data were similar to but lower than coverage estimates from the National Immunization Survey and Healthcare Effectiveness Data and Information Set. For the 25 health outcomes of interest studied, the rates of potential outcomes based on ICD-9 codes were generally higher than rates described in the literature, which are typically clinically confirmed cases. CONCLUSION: PRISM program's data on vaccine exposures and health outcomes appear complete enough to support robust safety monitoring.

Haemophilus influenzae type B in an immunocompetent, fully vaccinated ALL survivor.

A 7-year-old boy with a history of recurrent acute lymphoblastic leukemia (ALL), in remission, presented to primary care clinic after 2 days of progressive right hip pain with weight-bearing activities. He was otherwise asymptomatic at the time of presentation. Blood cultures revealed Gram-negative diplococci, which prompted an MRI that was significant for a hip joint effusion and femoral head bone marrow edema. The patient had no sick contacts and no significant past medical history other than ALL. The patient had been given all recommended childhood vaccinations. Arthrocentesis and needle biopsy of the femoral neck were not diagnostic for malignancy and revealed only mild hip joint inflammation, leading to a diagnosis of osteomyelitis. The organism in the original blood culture was identified as Haemophilus influenzae type b, ß-lactamase negative. Review of the patient's medical records showed a history of complete immunization to Haemophilus influenzae type b. An immunologic evaluation was made to determine if the patient retained immunity from his other vaccinations. Pathogen-specific antibody testing revealed detectable antibodies to polio but not measles, mumps, rubella, varicella-zoster virus, tetanus, diphtheria, pertussis, or hepatitis B. This loss of immunologic memory appears to be a rarely described side effect of ALL chemotherapy. There is currently no protocol to evaluate the immunologic memory of patients who underwent chemotherapy for ALL or to revaccinate them after their treatment. It is unclear whether the loss of immunologic memory is genuinely rare or is underdiagnosed because affected patients are protected by herd immunity.