Análisis económico de las vacunas 10-valente y 13-valente contra neumococo: revisión sistemática

Introducción: Las vacunas clásicamente han representado un método económico y eficaz para el control y prevención de múltiples enfermedades infecciosas. En los últimos años se han introducido nuevas vacunas contra neumococo a precios elevados, y los diferentes análisis económicos a nivel mundial de estas vacunas no muestran tendencias. El objetivo de este trabajo era resumir la evidencia existente a través de los diferentes estudios económicos evaluando las dos vacunas de segunda generación contra neumococo en la población a riesgo. Metodología: En este trabajo se realizo una revisión sistemática de la literatura en 8 bases de datos localizadas en diferentes partes del mundo y también que tuvieran literatura gris. Los artículos fueron inicialmente evaluados acorde a su titulo y resumen, posteriormente los elegidos se analizaron en su totalidad. Resultados: Se encontraron 404 artículos, de los cuales 20 fueron incluidos en el análisis final. Se encontró que la mayoría de los estudios se realizaron en áreas donde la enfermedad tiene una carga baja, como es Norte América y Europa, mientras que en los lugares del mundo donde la carga es mas alta, se realizaron pocos estudios. De igual manera se observo que la mayoría de los estudios mostraron por los menos ser costo efectivos respecto a la no vacunación, y en su totalidad las dos vacunas de segunda generación mostraron costo efectividad respecto a la vacunación con PCV-7. Los resultados de los estudios son muy heterogéneos, hasta dentro del mismo país, señalando la necesidad de guías para la conducción de este tipo de estudios. De igual manera, la mayoría de los estudios fueron financiados por farmacéuticas, mientras en un numero muy reducido por entes gubernamentales. Conclusiones: La mayoría de los estudios económicos sobre las vacunas de segunda generación contra neumococo han sido realizados en países con un alto índice de desarrollo económico y patrocinados por farmacéuticas. Dado que la mayoría de la carga de la enfermedad se encuentran en regiones con un menor nivel de desarrollo económico se deberían realizar mas en estas zonas. De igual manera, al ser la vacunación un asunto de salud publica y con un importante impacto económico los gobiernos deberían estar mas involucrados en los mismos.

Detection of Streptococcus pneumoniae strain cocolonization in the nasopharynx

Colonization with more than one distinct strain of the same species, also termed cocolonization, is a prerequisite for horizontal gene transfer between pneumococcal strains that may lead to change of the capsular serotype. Capsule switch has become an important issue since the introduction of conjugated pneumococcal polysaccharide vaccines. There is, however, a lack of techniques to detect multiple colonization by S. pneumoniae strains directly in nasopharyngeal samples. Two hundred eighty-seven nasopharyngeal swabs collected during the prevaccine era within a nationwide surveillance program were analyzed by a novel technique for the detection of cocolonization, based on PCR amplification of a noncoding region adjacent to the pneumolysin gene (plyNCR) and restriction fragment length polymorphism (RFLP) analysis. The numbers of strains and their relative abundance in cocolonized samples were determined by terminal RFLP. The pneumococcal carriage rate found by PCR was 51.6%, compared to 40.0% found by culture. Cocolonization was present in 9.5% (10/105) of samples, most (9/10) of which contained two strains in a ratio of between 1:1 and 17:1. Five of the 10 cocolonized samples showed combinations of vaccine types only (n = 2) or combinations of nonvaccine types only (n = 3). Carriers of multiple pneumococcal strains had received recent antibiotic treatment more often than those colonized with a single strain (33% versus 9%, P = 0.025). This new technique allows for the rapid and economical study of pneumococcal cocolonization in nasopharyngeal swabs. It will be valuable for the surveillance of S. pneumoniae epidemiology under vaccine selection pressure.

Serotype epidemiology of invasive pneumococcal disease in Swiss adults: A nationwide population-based study.

BACKGROUND In Switzerland, the heptavalent (PCV7) and 13-valent pneumococcal conjugate vaccine (PCV13) were recommended for all infants aged <2 years in 2007 and 2011, respectively. Due to herd effects, a protective impact on the invasive pneumococcal disease (IPD) rates in adults had been expected. METHODS Within this study, data from the nationwide mandatory surveillance was analyzed for all adult patients ≥16 years with IPD of known serotype/serogroup during 2003-2012. Trend (for IPD cases from 2003 to 2012) and logistic regression analyses (2007-2010) were performed to identify changes in serotype distribution and to identify the association of serotypes with age, clinical manifestations, comorbidities and case fatality, respectively. FINDINGS The proportion of PCV7 serotypes among all IPD cases (n=7678) significantly declined in adults from 44.7% (2003) before to 16.7% (2012) after the recommendation of PCV7 (P<0.001). In contrast, the proportion of non-PCV7 serogroup/serotypes increased for non-PCV13 but also PCV13 serotypes (not included in PCV7) at the same time. Serotype distribution varied significantly across ages, clinical manifestations and comorbidities. Serotype was furthermore associated with case fatality (P=0.001). In a multivariable logistic regression model, analyzing single serotypes showed that case-fatality was increased for the serotypes 3 (P=0.008), 19A (P=0.03) and 19F (P=0.005), compared to serotype 1 and 7F. CONCLUSION There was a significant decline in PCV7 serotypes among adults with IPD in Switzerland after introduction of childhood vaccination with PCV7. Pneumococcal serotypes were associated with case fatality, age, clinical manifestation and comorbidities of IPD in adults. These results may prove useful for future vaccine recommendations for adults in Switzerland.

Similar antibody concentrations in Filipino infants at age 9 months, after 1 or 3 doses of an adjuvanted, 11-valent pneumoccoccal diphtheria/tetanus-Conjugated Vaccine: a randomized controlled trial

In Filipino infants, 1 dose of an adjuvanted, 11-valent pneumococcal conjugate vaccine (serotypes 1, 4, 5, 7F, 9V, 19F, and 23F conjugated to tetanus protein; and serotypes 3, 6B, 14, and 18C conjugated to diphtheria toxoid) administered alone at age 18 weeks (11PncTD1) elicited similar antibody concentrations at age 9 months as those elicited by 3 doses (11PncTD3) administered concomitantly with national program vaccines, at ages 6, 10, and 14 weeks. Geometric mean antibody concentrations ranged from 0.36 mug/mL ( for serotype 18C) to 5.81 mug/mL (for serotype 4), for the 11PncTD1 vaccine, and from 0.32 mug/mL (for serotype 18C) to 5.01 mug/mL (for serotype 19F), for the 11PncTD3 vaccine. The proportion of infants with threshold antibody concentrations greater than or equal to0.35 mug/mL was also similar (ranges, 55.6%-100% for the 11PncTD1 vaccine and 42.9%-100% for the 11PncTD3 vaccine). The functional activity of antibodies expressed as opsonophagocytic activity titers was similar in the 11PncTD1 and 11PncTD3 groups. This finding is an important one for countries with financial constraints and high pneumococcal disease burden.

Genetic diversity and epidemiology of antimicrobial resistant Streptococcus pneumoniae isolates

Dissertation presented to obtain a Ph.D. degree in Biology, speciality in Microbiology, by Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Methods and challenges for the health impact assessment of vaccination programs in Latin America

ABSTRACT OBJECTIVE To describe methods and challenges faced in the health impact assessment of vaccination programs, focusing on the pneumococcal conjugate and rotavirus vaccines in Latin America and the Caribbean. METHODS For this narrative review, we searched for the terms "rotavirus", "pneumococcal", "conjugate vaccine", "vaccination", "program", and "impact" in the databases Medline and LILACS. The search was extended to the grey literature in Google Scholar. No limits were defined for publication year. Original articles on the health impact assessment of pneumococcal and rotavirus vaccination programs in Latin America and the Caribbean in English, Spanish or Portuguese were included. RESULTS We identified 207 articles. After removing duplicates and assessing eligibility, we reviewed 33 studies, 25 focusing on rotavirus and eight on pneumococcal vaccination programs. The most frequent studies were ecological, with time series analysis or comparing pre- and post-vaccination periods. The main data sources were: health information systems; population-, sentinel- or laboratory-based surveillance systems; statistics reports; and medical records from one or few health care services. Few studies used primary data. Hospitalization and death were the main outcomes assessed. CONCLUSIONS Over the last years, a significant number of health impact assessments of pneumococcal and rotavirus vaccination programs have been conducted in Latin America and the Caribbean. These studies were carried out few years after the programs were implemented, meet the basic methodological requirements and suggest positive health impact. Future assessments should consider methodological issues and challenges arisen in these first studies conducted in the region.

Insights into the epidemiology of drug-resistant Streptococcus pneumoniae and closely-related streptococci in the era of conjugate vaccines

In Portugal, the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) has led to significant changes in the population structure of Streptococcus pneumoniae. However, the levels of antimicrobial resistance have not decreased and have been a matter of concern. (...)

Etiology of community-acquired pneumonia in hospitalized children based on WHO clinical guidelines

Rapport de synthèse: Enjeux de la recherche : La pneumonie communautaire chez l'enfant est un problème de santé publique considérable. Elle est responsable de 2 millions de mort par année, 70% survenant dans les pays en voie de développement. Sous nos latitudes son incidence est de 40/1000 enfants par année, ce qui représente une morbidité importante. Deux difficultés surviennent lorsqu'on cherche à diagnostiquer une pneumonie. La première est de distinguer une pneumonie bactérienne d'une virale, particulièrement chez les petits enfants où les infections virales des voies respiratoires inférieures sont fréquentes. L'OMS a définit la pneumonie selon des critères exclusivement cliniques et une étude effectuée à Lausanne en 2000 a montré que ces critères peuvent être utilisés dans nos contrées. La seconde difficulté est de définir l'agent causal de la pneumonie, ceci pour plusieurs raisons : L'aspiration endotrachéale, seul examen fiable, ne peut être obtenue de routine chez l'enfant vu son caractère invasif, la culture des secrétions nasopharyngées reflète la flore physiologique de la sphère ORL et une bactériémie n'est présente que dans moins de 10% des pneumonies. L'étiologie de la pneumonie reste souvent inconnue, et de ce fait plusieurs enfants reçoivent des antibiotiques pour une infection non bactérienne ce qui contribue au développement de résistances. L'objectif de cette étude était d'effectuer une recherche extensive de l'agent causal de la pneumonie et de déterminer quels facteurs pourraient aider le clinicien à différencier une pneumonie virale de bactérienne, en corrélant l'étiologie avec la sévérité clinique et les marqueurs de l'inflammation. Contexte de la recherche : II s'agissait d'une étude prospective, multicentrique, incluant les enfants âgés de 2 mois à 5 ans hospitalisés pour une pneumonie, selon les critères de l'OMS, dans le service de pédiatrie de Lausanne et Genève entre mars 2003 et Décembre 2005, avant l'implantation de la vaccination antipneumococcique de routine. Chaque enfant, en plus des examens usuels, bénéficiait d'une recherche étiologique extensive : Culture virale et bactérienne, PCR (Mycoplasma Pneumoniae, Chlamydia Pneumoniae, Virus Influenza A et B, RSV A et B, Rhinovirus, Parainfluenza 1-3, enterovirus, human metapneumovirus, coronavirus OC43, E229 ; et NL 63) et détection d'AG viraux dans les sécrétions nasopharyngées ; sérologies virales et bactériennes à l'entrée et 3 semaines après la sortie (AG Influenza A et B, Parainfluenza 1,2 et 3, RSV, Adenovirus, M.Pneumoniae et S.Pneumoniae). Conclusions : Un agent pathogène a été découvert chez 86% des 99 patients retenus confirmant le fait que plus la recherche étiologique est étendue plus le pourcentage d'agent causal trouvé est élevé. Une infection bactérienne a été découverte chez 53% des patients dont 45% avaient une infection à S. Pneumoniae confirmant l'importance d'une vaccination antipneumococcique de routine. La déshydratation et les marqueurs de l'inflammation tels que la C-Reactive Protein et la Procalcitonine étaient significativement plus élevés dans les pneumonies bactériennes. Aucune corrélation n'a été trouvée entre le degré de sévérité de la pneumonie et l'étiologie. L'étude a confirmé la haute prévalence d'infections virales (67%) et de co-infection (33%) dans la pneumonie de l'enfant sans que l'on connaisse le rôle réel du virus dans la pathogenèse de la pneumonie. Perspectives : d'autres études à la suite de celle-ci devraient être effectuées en incluant les patients ambulatoires afin de déterminer, avec un collectif plus large de patient, une éventuelle corrélation entre sévérité clinique et étiologie. Abstract : Community-acquired pneumonia (CAP) is a major cause of death in developing countries and of morbidity in developed countries. The objective of the study was to define the causative agents among children hospitalized for CAP defined by WHO guidelines and to correlate etiology with clinical severity and surrogate markers. Investigations included an extensive etiological workup. A potential causative agent was detected in 86% of the 99 enrolled patients, with evidence of bacterial (53%), viral (67%), and mixed (33%) infections. Streptococcus pneumoniae was accounted for in 46% of CAP. Dehydration was the only clinical sign associated with bacterial pneumonia. CRP and PCT were significantly higher in bacterial infections. Increasing the number of diagnostic tests identifies potential causes of CAP in up to 86% of children, indicating a high prevalence of viruses and frequent co-infections. The high proportion of pneumococcal infections re-emphasizes the importance of pneumococcal immunization.

Nasopharyngeal carriage of individual Streptococcus pneumoniae serotypes during pediatric radiologically confirmed community acquired pneumonia following PCV7 introduction in Switzerland.

BACKGROUND: Community-acquired pneumonia (CAP) is a serious cause of morbidity among children in developed countries. The real impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal pneumonia is difficult to assess accurately. METHODS: Children aged ≤16 years with clinical and radiological pneumonia were enrolled in a multicenter prospective study. Children aged ≤16 years admitted for a minor elective surgery was recruited as controls. Nasopharyngeal samples for PCR serotyping of S. pneumoniae were obtained in both groups. Informations on age, gender, PCV7 vaccination status, day care/school attendance, siblings, tobacco exposure were collected. RESULTS: In children with CAP (n=236), 54% of the nasopharyngeal swabs were PCR-positive for S. pneumoniae compared to 32% in controls (n=105) (p=0.003). Serotype 19A was the most common pneumococcal serotype carried in children with CAP (13%) and in controls (15%). Most common serotypes were non-vaccine types (39.4% for CAP and 47.1% for controls) and serotypes included only in PCV13 (32.3% for CAP and 23.5% for controls). There was no significant difference in vaccine serotype distribution between the two groups. In fully vaccinated children with CAP, the proportion of serotypes carried only in PCV13 was higher (51.4%) than in partially vaccinated or non vaccinated children (27.6% and 28.6% respectively, p=0.037). CONCLUSIONS: Two to 4 years following introduction of PCV7, predominant S. pneumoniae serotypes carried in children with CAP were non PCV7 serotypes, and the 6 new serotypes included in PCV13 accounted for 51.4% of carried serotypes in fully vaccinated children.

Enfermedad neumocócica invasiva en adultos: Cambios en la presentación clinica y evolución tras la introducción del la vacuna neumococica conjugada heptavalente en niños

La introducción de la vacuna neumocócica conjugada ha modificado los serotipos causantes de enfermedad neumocócica invasiva (ENI). El objetivo de este estudio fue analizar las diferencias en la presentación clínica entre la época pre y postvacunal. Realizamos un estudio observacional de todos los adultos hospitalizados con ENI, entre 1997 y 2001 (periodo prevacunal), y de 2006 a 2009 (periodo postvacunal). Comparamos la incidencia, la distribución de serotipos y la presentación clínica entre ambos periodos. Nuestros hallazgos sugieren que la aparición de nuevos serotipos puede asociarse con un aumento de la incidencia de ENI, especialmente en adultos jóvenes, y una mayor severidad en la presentación.

Niveles de anticuerpos bactericidas frente a meningococo C tras la vacunación de niños de 2 a 6 años de edad en Andalucía.

BACKGROUND In 1997, 18.5% of the cases of Meningococcal Disease caused b serogroup C in Andalusia were children between 2 and 4 years of age; ages where the initial immune response and the duration of the capsular A + C meningococcal polysaccharide vaccine is less than in older age groups. Research was designed in order to measure the immune response produced by this vaccine in children from 2 to 6 years of age and to compare it with the natural immunity present in unvaccinated children. METHODS I. Dual monitoring study: a) groups of children vaccinated previously and control groups, b) groups of children who were going to be vaccinated, for pre and post-vaccination (1, 6 and 12 months) analysis and a control group. II. The bactericidal activity was measured according to the standardised protocol of the CDC with regard to the strain of N. meningitidis C-11. The sera with bactericidal activity (TAB) > 1:8 were considered to be protective. RESULTS 1 and 2 months following vaccination, the proportion of TAB > 1:8 was significantly higher than that of the control group (65.6% and 73% in comparison to 2.2% and 12%). In the pre-vaccine and post-vaccine (after 6, 7, 12 and 13 months) verification, no significant difference between vaccinated individuals and controls was observed. CONCLUSIONS The differences between vaccinated and unvaccinated individuals 1 and 2 months following vaccination indicate seroconversion in the vaccinated individuals. For the age group of between 2 to 6 years of age, the bactericidal activity acquired decline quickly, as, after 6 months, differences between this group and the control group are no longer observed.

Etiology of community-acquired pneumonia in hospitalized children based on WHO clinical guidelines.

Community-acquired pneumonia (CAP) is a major cause of death in developing countries and of morbidity in developed countries. The objective of the study was to define the causative agents among children hospitalized for CAP defined by WHO guidelines and to correlate etiology with clinical severity and surrogate markers. Investigations included an extensive etiological workup. A potential causative agent was detected in 86% of the 99 enrolled patients, with evidence of bacterial (53%), viral (67%), and mixed (33%) infections. Streptococcus pneumoniae was accounted for in 46% of CAP. Dehydration was the only clinical sign associated with bacterial pneumonia. CRP and PCT were significantly higher in bacterial infections. Increasing the number of diagnostic tests identifies potential causes of CAP in up to 86% of children, indicating a high prevalence of viruses and frequent co-infections. The high proportion of pneumococcal infections re-emphasizes the importance of pneumococcal immunization.

Hospital costs related to streptococcal meningitis among children in Sao Jose dos Campos, Sao Paulo State, Brazil

Knowledge of hospital costs is highly important for public health decision-making. This study aimed to estimate direct hospital costs related to pneumococcal meningitis in children 13 years or younger in the city of Sao Jose dos Campos, Sao Paulo State, Brazil, from January 1999 to December 2008. Data were obtained from medical records. Hospital costs were calculated according to the mixed method for measurement of quantities of items with identified costs and value attribution to items consumed (micro-costing and gross-costing). All costs were calculated according to monetary values for November 2009 and in Brazilian currency (Real). Epi Info 3.5.1 was used for frequencies and means analysis. Forty-one cases were reported. Direct hospital costs varied from R$ 1,277.90 to R$ 19,887.56 (mean = R$ 5,666.43), or 10 to 20 times the mean cost of hospitalization for other diseases. Hospital staff labor was the highest cost, followed by medication, procedures, supplies, and lab tests.

Moraxella catarrhalis - pathogen or commensal?

Moraxella catarrhalis is an exclusively human commensal and mucosal pathogen. Its role as a disease-causing organism has long been questioned. Today, it is recognized as one of the major causes of acute otitis media in children, and its relative frequency of isolation from both the nasopharynx and the middle ear cavity has increased since the introduction of the heptavalent pneumococcal conjugate vaccine, which is associated with a shift in the composition of the nasopharyngeal flora in infants and young children. Although otitis media caused by M. catarrhalis is generally believed to be mild in comparison with pneumococcal disease, numerous putative virulence factors have now been identified and it has been shown that several surface components of M. catarrhalis induce mucosal inflammation. In adults with chronic obstructive pulmonary disease (COPD), M. catarrhalis is now a well-established trigger of approximately 10% of acute inflammatory exacerbations.Although the so-called cold shock response is a well-described bacterial stress response in species such as Escherichia coli, Bacillus subtilis or - more recently - Staphylococcus aureus, M. catarrhalis is the only typical nasopharyngeal pathogen in which this response has been investigated. Indeed, a 3-h 26°C cold shock, which may occur physiologically, when humans inspire cold air for prolonged periods of time, increases epithelial cell adherence and enhances proinflammatory host responses and may thus contribute to the symptoms referred to as common cold, which typically are attributed to viral infections.

Serotype/serogroup-specific antibiotic non-susceptibility of invasive and non-invasive Streptococcus pneumoniae, Switzerland, 2004 to 2014.

Concurrent analysis of antibiotic resistance of colonising and invasive Streptococcus pneumoniae gives a more accurate picture than looking at either of them separately. Therefore, we analysed 2,129 non-invasive and 10,996 invasive pneumococcal isolates from Switzerland from 2004 to 2014, which spans the time before and after the introduction of the heptavalent (PCV7) and 13-valent (PCV13) conjugated pneumococcal polysaccharide vaccines. Serotype/serogroup information was linked with all antibiotic resistance profiles. During the study period, the proportion of non-susceptible non-invasive and invasive isolates significantly decreased for penicillin, ceftriaxone, erythromycin and trimethoprim/sulfamethoxazole (TMP-SMX). This was most apparent in non-invasive isolates from study subjects younger than five years (penicillin (p = 0.006), erythromycin (p = 0.01) and TMP-SMX (p = 0.002)). Resistant serotypes/serogroups included in PCV7 and/or PCV13 decreased and were replaced by non-PCV13 serotypes (6C and 15B/C). Serotype/serogroup-specific antibiotic resistance rates were comparable between invasive and non-invasive isolates. Adjusted odds ratios of serotype/serogroup-specific penicillin resistance were significantly higher in the west of Switzerland for serotype 6B (1.8; 95% confidence interval (CI): 1.4-4.8), 9V (3.4; 95% CI: 2.0-5.7), 14 (5.3; 95% CI: 3.8-7.5), 19A (2.2; 95% CI: 1.6-3.1) and 19F (3.1; 95% CI: 2.1-4.6), probably due to variations in the antibiotic consumption.