Análisis económico de las vacunas del primer año de vida con componente pertussis en el contexto de la ini-ciativa mundial de erradicación de la poliomielitis en Argentina / Vaccination in children under 1 year with pertussis component in the context of the global initiative for the eradication of poliomyelitis in Argentina: economic analysis

INTRODUCCIÓN: La Iniciativa Mundial de Erradicación de la Polio promueve la introducción de vacuna de polio inactivada (IPV) en sus programas, con la posterior retirada de Sabin (bOPV). OBJETIVO: Construir un modelo de económico que compare diferentes esquemas de vacunación para la prevención de polio y tosferina en el primer año de vida. Material y MÉTODOS: Análisis de cuatro escenarios de vacunación del esquema primario para Argentina, en base a los precios de las vacunas, costos del programa y reactogenicidad de vacuna celular o acelular para Bordetella pertussis: - Escenario 1 (caso base): dos dosis de IPV, una dosis de bOPV y tres dosis de vacuna pentavalente (DTwP-HB-Hib); - Escenario 2: tres dosis IPV y de pentavalente; - Escenario 3: tres dosis de hexavalente (DTaP-HepB-IPV-Hib); - Escenario 4: dos dosis de hexavalente más una dosis de pentavalente más IPV. RESULTADOS: El costo incremental en base al escenario 1 fue de USD 3.716.671; 19.696.668 y 14.383.341 para los escenarios 2, 3 y 4, respectivamente. Para la reactogenicidad, la diferencia fue de USD -14.178.240 comparado el caso base con el escenario 3. DISCUSIÓN: La inversión de incorporación de full IPV y costos asociados se modifica según tipo de vacuna y reactogenicidad asociada al componente B. pertussis.

BACKGROUND: Global Polio Eradication Initiative promotes the introduction of inactivated polio vaccine (IPV) in its programs, with withdrawal of Sabin (bOPV). There is no an economic analysis of the investment related to the incorporation of IPV vaccines together with a whole cell Bordetella pertussis vaccine or combined with acellular hexavalent. AIM: An economic model that compares different vaccination schemes for the prevention of polio and pertussis in the first year of life was carried out. METHODS: Four vaccination scenarios for the primary scheme based on Argentina demographic and costs data were developed: - Scenario 1 (base case): two doses of IPV, one dose of bOPV and three doses of pentavalent (DTwP-HepB-Hib) vaccine; - Scenario 2: three doses of IPV plus three doses of pentavalent; - Scenario 3: three doses of hexavalent; - Scenario 4: two doses of hexavalent plus one dose of pentavalent plus IPV. RESULTS: The incremental cost based on scenario 1 was USD 3.716.671; 19.696.668 and 14.383.341 for scenarios 2, 3 and 4 respectively. In terms of reactogenicity savings was -14.178.240 compared base case with scenario 3. DISCUSSION: Full IPV introduction investment and costs associated were modified according to the type of vaccine and reactogenicity related with the B. pertussis component.

Poliomielitis, una historia de inicio triste y final feliz / Poliomyelitis, a story with a sad beginning and a happy ending

Se desarrollan los principales elementos históricos en el estudio y la lucha contra la poliomielitis, su aislamiento por Karl Landsteiner en 1909, la primera vacuna con virus muerto (Jonas Salk, 1955), la segunda vacuna con virus vivo atenuado (Albert Sabin, 1961) y la reducción paulatina de la polio en todo el mundo, hasta llegar a menos de 200 casos al año (virus salvaje)(AU)

The main historical events in the study and fight against polio are shown, its isolation by Karl Landsteiner in 1909, the development of the first vaccine with dead virus (Jonas Salk, 1955), the second vaccine with live attenuated virus (Albert Sabin, 1961) and the gradual reduction of polio worldwide, reaching less than 200 cases a year (wild virus)(AU)

Prevalence of neutralizing antibodies against poliovirus 1, 2, and 3 in healthcare professionals aged 20-50 years / Prevalência de anticorpos neutralizantes contra poliovírus 1, 2 e 3 em profissionais de saúde de 20 a 50 anos de idade

ABSTRACT Objective: To describe the prevalence of neutralizing antibodies against poliovirus (PV1, PV2, and PV3) in blood samples of healthcare professionals aged 20 to 50 years. Methods: Health professionals who serve children at Darcy Vargas Children's Hospital and the Department of Pediatrics of Irmandade da Santa Casa de São Paulo. The sample size was calculated at 323 participants. The Mantel-Haenszel chi-square was used to verify differences between groups. The neutralization reaction detected human poliovirus antibodies. For susceptible individuals, vaccination with the inactivated+triple acellular polio vaccine was performed, and neutralizing antibodies were re-dosed after one week. Results: 333 professionals were studied - 92.8% were immune to poliovirus 1, 86.5% to poliovirus 2, and 63.3% to poliovirus 3; 37% had titers less than 1:8 for any serotype, 5;1% had titers below 1:8 for all three. Vaccination with inactivated polio vaccine was performed for susceptible participants, and neutralizing antibodies were dosed after one week, showing increased titers for all polioviruses. Conclusions: Despite the detection of a significant percentage of individuals with low poliovirus antibody titer, the challenge with vaccination demonstrated immune response compatible with poliovirus immunity.

RESUMO Objetivo: Descrever a prevalência de anticorpos neutralizantes contra poliovírus (tipos 1, 2 e 3) em amostra de sangue de profissionais de saúde com idade de 20 a 50 anos. Métodos: Profissionais de saúde que atendem crianças do Hospital Infantil Darcy Vargas e do Departamento de Pediatria da Irmandade da Santa Casa de São Paulo. O tamanho da amostra foi de 323 participantes. Os anticorpos contra poliovírus humanos foram detectados pela reação de neutralização. Para os indivíduos suscetíveis, foram administradas vacina para poliomielite inativada+tríplice e nova dosagem de anticorpos neutralizantes após uma semana. Utilizou-se o teste do qui-quadrado de Mantel-Haenszel para verificar as diferenças entre os grupos. Resultados: Foram estudados 333 profissionais - 92,8% eram imunes ao poliovírus 1; 86,5%, ao poliovírus 2; 63,57%, ao poliovírus 3; 37% apresentaram títulos inferiores a 1:8 para qualquer sorotipo; 5,1% tinham títulos abaixo de 1:8 para os três. Após a vacinação dos suscetíveis, houve elevação dos títulos para todos os poliovírus. Conclusões: Apesar da detecção de percentual significativo de indivíduos com baixo título de anticorpos para poliovírus, o desafio da vacinação demonstrou resposta imune robusta compatível.

Estado actual de la poliomielitis en Latinoamérica

Resumen La vacuna oral contra el poliovirus (OPV) ha sido fundamental en controlar la epidemia de poliomielitis, y destaca por su seguridad, eficacia, facilidad de administración oral y bajo costo. Sin embargo, a pesar de estas ventajas, al tratarse de una vacuna con virus vivos atenuados, existe la posibilidad de mutaciones que confieran neurovirulencia. Por ende, es importante la vigilancia de parálisis flácida aguda (PFA), ya sea asociada a las vacunas atenuadas (VAPP) o a los virus derivados de vacunas (VDPV). En esta revisión presentamos datos importantes de Latinoamérica en los últimos años, donde se revisan los datos de VDPV de transmisión comunitaria, de origen ambiguo y asociadas con inmunodeficiencias. Debido a la presencia de VDPV, es importante fortalecer el sistema de vigilancia epidemiológica por PFA, con datos muy inferiores a los recomendados en estos últimos años en las Américas. Adicionalmente, es fundamental mejorar las coberturas vacunales para reducir la cantidad de lactantes en riesgo de adquirir poliomielitis. En consecuencia, presentamos las tasas de cobertura vacunal con la vacuna inactivada contra el poliovirus (IPV) en la región y analizamos los programas de vacunación contra la poliomielitis en concordancia con las recomendaciones de la Sociedad Latinoamericana de Infectología Pediátrica (SLIPE; mínimo 3 dosis de IPV) y del Grupo de Expertos en Asesoramiento Estratégico (SAGE) sobre Inmunización de la OMS (mínimo 2 dosis de IPV). El estudio concluye con recomendaciones de los autores para el cambio de OPV a uso exclusivo de IPV, para aumentar las coberturas vacunales y para reforzar la vigilancia por PFA en la región.

Abstract Oral poliovirus vaccine (OPV) has been instrumental in controlling the polio epidemic, and stands out for its safety, efficacy, ease of oral administration, and low cost. However, despite these advantages, as it is a live attenuated virus vaccine, there is the possibility of mutations that confer neurovirulence. Therefore, surveillance for acute flaccid paralysis (AFP) is important, whether associated with live vaccines (VAPP) or vaccine-derived viruses (VDPV). In this review we present important data from Latin America in recent years, where data on VDPV of community transmission, of ambiguous origin and associated with immunodeficiencies are reviewed. Due to the presence of VDPV, it is important to strengthen the epidemiological surveillance system for AFP, with data much lower than those recommended in recent years in the Americas. Additionally, it is essential to improve vaccination coverage to reduce the number of infants at risk of acquiring poliomyelitis. Consequently, we present the vaccination coverage rates with the inactivated vaccine against poliovirus (IPV) in the region and analyze the vaccination programs against poliomyelitis in accordance with the recommendations of the Latin American Society of Pediatric Infectious Diseases (SLIPE; minimum 3 doses of IPV) and the WHO Strategic Advisory Expert Group (SAGE) on Immunization (minimum 2 doses of IPV). The study concludes with recommendations from the authors for the change from OPV to exclusive use of IPV, to increase vaccination coverage and to strengthen surveillance for AFP in the region.

Padronização de teste para quantificar anticorpos anti-poliovírus utilizando vírus vacinal / Standardization of a test for quantifying the antibodies against poliovirus using the vaccine virus

A poliomielite é uma doença endêmica no Afeganistão e no Paquistão, apesar dos esforços para ser erradicada, representando uma ameaça para outros países principalmente devido às viagens internacionais. A Organização Mundial da Saúde (OMS) tem como objetivo erradicar a poliomielite causada pelo poliovírus selvagem no mundo. O requisito essencial para a erradicação da poliomielite é a eliminação da cepa do poliovírus selvagem, que é empregada no teste padrão-ouro. Com o intuito de auxiliar na erradicação do poliovírus selvagem, o objetivo deste estudo foi modificar o teste padrão-ouro usando o poliovírus derivado da vacina oral atenuada. Foram testados 63 soros pelo ensaio de neutralização utilizando-se antígenos vacinais. A concordância do sorotipo 1 (k=0,74) foi considerada substancial, enquanto o sorotipo 2 (k=1,00) e sorotipo 3 (k= 0,95) foram consideradas quase perfeitas. A sensibilidade dos testes de soroneutralização utilizando os sorotipos 1, 2 e 3 foi de 94,83%, 100,00% e 100,00%, respectivamente. Em conclusão, o ensaio com antígenos vacinais pode ser usado como procedimento laboratorial seguro, especialmente em estudos de vigilância em larga escala. (AU)

Poliomyelitis is an endemic disease in Afghanistan and Pakistan in despite of the efforts to eradicate it, and it represents a threat to other countries mainly due to the international trips. The World Health Organization (WHO) aims at eradicating the polio disease worldwide. An essential requirement for eradicating the poliomyelitis is the elimination of the wild poliovirus strain, which is employed in the gold standard test. As a support for the eradication of wild poliovirus, the present study aimed at modifying the gold standard test by using poliovirus derived from the oral attenuated vaccine. Sixty-three sera samples were tested by neutralization assay using vaccine antigens. The degree of agreement of the serotype 1 (k=0.74) was considered substantial, while the serotype 2 (k=1.00) and 3 (k= 0.95) showed almost perfect agreement. The sensitivity of serotypes 1, 2 and 3 was 94.83%, 100.00% and 100.00%, respectively. In conclusion, the assay with the vaccine antigens can be used as a safe application, especially for large-scale surveillance studies. (AU)

Remarks on the possibility of introducing the fractionated dose of the inactivated poliomyelitis vaccine in the Latin American Child Immunization Schedule

Abstract Given that the last notified case of poliomyelitis due to wild poliovirus type 2 was in 1999, in 2012, the Strategic Advisory Group of Experts on Immunization (SAGE) of the World Health Organization (WHO) recommended the withdrawal of the type 2 component of oral polio vaccine (OPV) and the introduction of a bivalent OPV (bOPV) in all countries by 2016. WHO recommended also that the withdrawal should be preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunization schedules. The introduction of IPV prior to the change of the bOPV in 2016 to trivalent OPV (tOPV) was based on the concept of ensuring that a substantial proportion of the population would be protected against type 2 polio after the removal of the type 2 OPV. However, the world's two producers of IPV (Bilthoven Biologicals and Sanofi) have faced problems in the production of this vaccine and therefore reported a reduction of the global supply of IPV. In response to the potential shortage of IPV, at a meeting held on March 10 2017, the SAGE and Technical Advisory Group (TAG) of the Pan American Health Organization (PAHO) urged the countries in the Latin American region to replace the routine administration of the full doses of inactivated polio vaccine (IPV-C) in the immunization schedule (administered by intramuscular route), administering a fraction of the full dose in two intradermal shots (IPV-f). The possibility of this strategy was analyzed by opinion leaders convened by the Paraguayan Society of Pediatrics with the support of the Latin American Society of Pediatric Infectious Diseases (SLIPE) and Latin American Association of Pediatrics (ALAPE). This document presents the results of the discussion.

Consideraciones referente a la posibilidad de introducir la dosis fraccionada de la vacuna antipoliomielitis inactivada en el calendario de Inmunizaciones del Niño Latinoamericano / Remarks on the possibility of the introduction of fractionated dose of the inactivated poliomyelitis vaccine in the Latin American Child Immunization Schedule

As last notified case of poliomyelitis due to wild poliovirus type 2 was 1999, in 2012, the Strategic Advisory Group of Experts on Immunization (SAGE) of the World Health Organization (WHO) recommended the withdrawal of the type 2 component of oral polio vaccine (OPV) and the introduction of bivalent OPV (bOPV) in all countries by 2016. WHO recommended also that the withdrawal should be preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunization schedules. The introduction of IPV prior to the change of the bOPV in 2016 to trivalent OPV (tOPV) was based on the concept of ensuring that a substantial proportion of the population would be protected against type 2 polio after the removal of the type 2 OPV. However, the world's two producers of IPV (Bilthoven Biologicals and Sanofi) have faced problems in the production of this vaccine and therefore reported reduction in IPV global supply. In response to the possible shortage of IPV, the SAGE and Technical Adviser Group (TAG) of the Pan American Health Organization (PAHO), in the meeting of March 10, 2017, has urged that countries in the Latinamerican region should replace the routine administration of the full doses of polio inactivated vaccine (IPV-C) in the immunization schedule (administered by intramuscular route) by the administration of a fraction of the full dose in two shots by intradermal route (IPV-f). The possibility of this strategy was analyzed by leaders of opinions gathered by the call of the Paraguayan Pediatric Society with the support of the Latin American Society of Pediatric Infectious Diseases (SLIPE) and Latin American Association of Pediatrics (ALAPE). The results of the discussion are presented in this document.

Síndrome de Nicolau por la administración de la vacuna séxtuple intramuscular en un lactante de 6 meses / Nicolau syndrome induced by intramuscular injection of a hexavalent vaccine in a 6-month-old girl

El síndrome de Nicolau, también conocido como embolia cutis medicamentosa o dermatitis livedoide, es una reacción cutánea infrecuente, caracterizada por una necrosis de la piel y los tejidos blandos de aparición súbita luego de la aplicación intramuscular de algunas drogas. Presentamos a un bebé de 6 meses de edad que, al recibir la tercera dosis de la vacuna séxtuple intramuscular, desarrolló una lesión necrótica con reticulado violáceo periférico en el sitio de aplicación. Se destaca la importancia del diagnóstico precoz a fin de instaurar un adecuado tratamiento y seguimiento para evitar complicaciones secundarias a la isquemia.

Nicolau syndrome, also known as embolia cutis medicamentosa or livedo-like dermatitis, is a sudden tissue necrosis, a rare complication of intramuscular injection of some drugs. We report a case of a 6-month-old girl who received intramuscularly the third dose of hexavalent vaccine (DTaP-HVB-IPV/HIb), and immediately presented a livedoid lesion around the injection site, progressing to necrosis. We reinforce the importance of early diagnosis to perform a suitable treatment and clinical follow-up to avoid ischemic secondary complications.

Experiencia argentina en la etapa final de erradicación de la polio: cambio de vacuna oral trivalente a bivalente / Argentinian experience to finish polio eradication: switch from trivalent to bivalent oral poliovirus vaccine

Entre el 17 de abril y el 1 de mayo de 2016, 155 países en todo el mundo cambiaron el uso de la vacuna oral trivalente, que protege contra los tres tipos de poliovirus (1, 2 y 3), por la vacuna oral bivalente, que protege contra los poliovirus tipo 1 y 3. Este cambio señala el mayor esfuerzocoordinado globalmente en la historia de las vacunas. En Argentina se realizó el pasado 29 de abril, con una intensa planificación previa y una posterior validación.

Internações sensíveis à atenção primária específicas de mulheres / Sensitive female-specific hospitalization in primary care

Objetivou-se analisar as internações por condições sensíveis à atenção primária (ICSAP) específicas em mulheres e os fatores que determinam ou influenciam a ocorrência dessas internações (fatores socioeconômicos, sociodemográficos e controle de saúde) por meio de um inquérito de morbidade hospitalar realizado com amostra de 429 mulheres internadas em hospitais conveniados ao Sistema Único de Saúde. O percentual de ICSAP foi 49,42% (n = 212), com destaque para as internações específicas do sexo feminino 19,35% (n = 83). Associaram ao risco de internar por CSAP: idade superior a 60 anos, baixa escolaridade, internação prévia, realização de controle regular de saúde, falta de vínculo com a Estratégia Saúde da Família (ESF) e ser gestante. As causas evidentes foram as condições relacionadas à gravidez, ao parto e ao puerpério e às inflamações nos órgãos pélvicos femininos. Os resultados sugerem falhas no atendimento ambulatorial que deveria ser oportuno e resolutivo no contexto da saúde da mulher.

The scope of this paper was to analyze female-specific sensitive hospitalization occurring in primary care conditions and factors that determine or affect the occurrence of such hospitalizations (social, economic and demographic factors; health control). Analysis was performed by surveys on hospital morbidity with a sample of 429 females attended in Unified Health System (SUS) contracted hospitals. The sensitive hospitalizations percentage in primary care reached 49.42% (n = 212), highlighting female-specific hospitalization at 19.35% (n = 83). Hospitalization risks comprised elderly people over sixty, low schooling, previous hospitalizations, normal health control, lack of association with the Family Health Strategy and pregnancy. Evident causes were related to conditions of pregnancy, childbirth, post-partum and inflammations of the female pelvic organs. Results suggested flaws in outpatient attendance that should be adequate and provide solutions in women’s health.

Hacia la erradicación de la poliomielitis: logros y retos en México

Desde la implementación de las estrategias globales de erradicación, la incidencia de parálisis poliomielítica ha disminuido dramáticamente. Cuatro estrategias han contribuido notablemente: a) Altas coberturas de inmunización con vacuna oral de polio (VOP), b) Inmunización suplementaria durante los Días Nacionales de Vacunación, c) Vigilancia epidemiológica efectiva de casos de parálisis flácida aguda (PFA), y d) Bloqueos vacunales en zonas de alto riesgo. Sólo quedan tres países polioendémicos, no obstante, cualquier país corre el riesgo potencial de importación del virus de algunas de estas áreas, de la liberación accidental del virus resguardado en laboratorios de diagnóstico clínico o investigación, o de la presencia de virus circulantes derivados de vacuna en el medio ambiente. Este documento pretende exponer los antecedentes históricos que hicieron posible la eliminación de la enfermedad en México, así como los retos para lograr un mundo libre de poliomielitis.

Since the strategies to eradicate polio were implemented, the incidence of paralytic polio has dropped dramatically. Four main strategies have greatly contributed: a) High immunization coverage rate with oral polio vaccine (OPV), b) Supplementary immunization activities during the National Immunizations Days c) An effective epidemiological surveillance system for acute flaccid paralysis (AFP) and d) Intensified immunization activities in high risk areas. Three countries remain polio endemic, nevertheless, any country has a potential risk of the virus importation from one of these endemic areas; an accidental release of poliovirus from a research or clinical laboratory, or from having a circulating vaccine-derived poliovirus in the environment. The present document aims to provide an historical background that made possible the disease elimination in Mexico. Moreover, we discuss the challenges that every country needs to face in order to achieve a polio-free world.

Polio / Polio

Polio continúa endémica en: Nigeria, Afganistán Pakistán e India. La iniciativa global de erradicación de polio de la OMS estableció que para 2013 no debe haber ningún niño paralítico en el mundo por el virus salvaje o por el virus derivado de la vacuna. En esta revisión se describen ambas vacunas contra el polio, la oral y la inactivada, su inmunogenicidad, seguridad y las condiciones a cumplir por un paíspara que cambie su esquema de vacunación de polio oral a inactivada. La vacuna polio oral ha permitido la erradicación de la enfermedaden varios continentes incluyendo América; sin embargo conlleva riesgos, tales como polio paralítica asociada a vacuna (VAP-siglas en inglés-) y parálisis producida por polio virus derivado de la vacuna (VDP-siglas en inglés-). La Vacuna Polio Inactivada (VPI) es segura e inmunogénica, puede ser administrada en combinaciones vacunales. Para que un país cambie a VPI debe tener cobertura y esquemaóptimo de esta vacuna, 90% de, cobertura de DTP3, vigilancia adecuada de parálisis flácida, no estar próximo en la actualidad o recientemente a un país con polio endémico. Altas coberturas vacunales son esenciales par asegurar una inmunidad adecuada de lapoblación

Polio remains endemic in Nigeria, Afghanistan, Pakistan, India. Strategic plan of Global Poliomyelitis Eradication Initiative (GPEI) of the WHO is that by 2013 no child will be paralyzed by a wild or vaccine derived poliovirus. This paper describes both oral and inactivated vaccine, safety concerns with the use of OPV, immunogenicity of IPV and the conditions to be full filled in order for a country to deliverIPV as a regular vaccine schedule. Oral polio vaccine has successfully contributed to global polio eradication in several continents including America. However, it carries risks, such as Vaccine Derived Poliovirus (VDP) and Vaccine Associated Paralytic Polio (VAPP). Inactivated Poliovirus Vaccine (IPV) is safe and immunogenic; it may be administered as monovalent or in a combined shot. Countries opting to switch from OPV to IPV should have: optimal IPV coverage and schedule, 90% of DTP 3 coverage, good surveillance of flaccid paralysis cases, and should not be near a country with endemic polio recently or at the present time. Are neither currently or were notrecently polio endemic nor has close contacts with such areas. High immunization coverage is essential to ensure adequate populationimmunity

Reactogenicidad asociada a la administración intradérmica de la vacuna de polio inactivada con un inyector sin aguja / Reactogenicity associated to the intradermally administered inactivated poliovirus vaccine with a needle-free injector

INTRODUCCIÓN: en la medida en que la meta de la erradicación de la poliomielitis llega a su concreción, la necesidad de contar con una vacuna de polio inactivada asequible y apropiada para el uso en países en vías de desarrollo se ha convertido en una meta para la Organización Mundial de la Salud. OBJETIVO: la evaluación de la reactogenicidad de la vacuna de polio inactivada. MÉTODOS: se realizó un estudio multicéntrico con diseño experimental, correspondiente a Fase I-II de un ensayo clínico controlado, aleatorio y a simple ciegas, en 471 lactantes sanos de ambos sexos nacidos entre los meses de julio y agosto de 2006 en Camagüey, cuyos padres brindaron su consentimiento por escrito y que cumplieron con los criterios de inclusión establecidos. Los niños recibieron a las 6, 10 y 14 semanas del nacimiento, tres dosis de vacuna de polio inactivada del Instituto de Sueros de Dinamarca, autorizada para su uso en esta investigación por las autoridades regulatorias nacionales. Al grupo de estudio A, se le administró por la vía intradérmica la dosis reducida de 0,1 mL de vacuna de polio inactivada en la cara anterolateral del muslo izquierdo utilizando el inyector sin aguja Biojector® 2000. El grupo control B recibió la dosis usual de 0,5 mL por la vía intramuscular profunda, administrada en el mismo sitio descrito antes con una jeringuilla prellenada. Se observaron los eventos adversos durante la primera hora, 24, 48, y 72 h subsiguientes, así como a los 7 y 30 d de administrada la vacuna. La reactogenicidad se evaluó inicialmente por el pediatra del área y luego por el médico de familia mediante la observación de los eventos adversos. RESULTADOS: 79,6 por ciento del total de niños asignados al grupo A y 75 por ciento del grupo B finalizaron el protocolo de investigación. No se detectaron eventos adversos moderados o serios. Predominaron las reacciones adversas locales menores, sobre todo induración, dolor y enrojecimiento en el sitio de la inyección. CONCLUSIÓN: el ensayo demostró la seguridad de la vacuna de polio inactivada para su uso por vía intramuscular y reconoció la seguridad del uso de la vía intradérmica y del inyector sin agujas.

INTRODUCTION: as the goal of poliomyelitis eradication is about to be accomplished, the need for an affordable and appropriate inactivated poliovirus vaccine (IPV) for use in developing countries has become a target for WHO. OBJECTIVE: to evaluate the reactogenicity of the inactivated poliovirus vaccine. METHOD: an experimental-type multicenter study was conducted, as part of a Phase I-II controlled clinical randomized and blinded assay, in 471 healthy infants of both sexes born in July and August 2006 in Camagüey province. The parents of the children who met the inclusion criteria gave their consent in writing. The children received three doses of the inactivated poliovirus vaccine at 6, 10 and 14 weeks after birth. This vaccine came form the Institute of Sera in Denmark and had been approved for use in this assay by the Cuban regularoty authorities, Low 0.1 ml inactivated poliovirus vaccine dose was intradermally administered to the study group A in the anterolateral side of the left thigh using the needle-free injector called Biojector ® 2000. The usual 0.5 mL dose was intramuscularly administered on the same site using a pre-filled syringe. The adverse events were observed during the first hour, 24, 48, and 72 hours after the immunization, as well as 7 and 30 days afterwards. The pediatrician in charge of the health area evaluated the reactogenicity at first and then the family physician was in charge of observing the adverse events in the remaining period. RESULTS: the 79.6 percent of children in group A and 75 percent in group B completed the research protocol. Mild local adverse reactions prevailed, mainly induration, pain and redness at the injection site. CONCLUSION: the clinical trial proved the safety of the inactivated poliovirus vaccine for intramuscular administration, and also showed the safety of the intradermal route of administration and of the needle-free injector.

Impacto económico de la introducción de la vacuna inactivada inyectable contra la poliomielitis en Colombia / Economic impact of introducing the injectable inactivated polio vaccine in Colombia

OBJETIVOS: Evaluar la relación costo-efectividad de la introducción de la vacuna inyectable contra la poliomielitis (VIP) en Colombia con respecto al sistema actual basado en el empleo de la vacuna oral (VOP). MÉTODOS: Se diseñó un modelo de Markov basado en una cohorte hipotética de recién nacidos que recibiría la VIP o la VOP con un seguimiento de dos años y estimaciones mensuales del número de casos de poliomielitis paralítica asociada con la vacuna (PPAV). El análisis del costo se realizó desde la perspectiva del asegurador (costos a lo largo de la vida) y la sociedad (casos de PPAV evitados y años de vida ajustados por discapacidad [AVAD] evitados). RESULTADOS: Entre 1988 y 1998 se aplicaron en Colombia 22,5 millones de dosis de la VOP y se detectaron nueve casos de PPAV, para una tasa de 4,0 ¥ 10-7 por dosis. Según el modelo, se podrían esperar entre 2 y 4 casos de PPAV en los dos años de seguimiento. El costo de tratar los casos de PPAV sería de US$ 302 008, con costos de vacunación con la VOP de US$ 737 037 y de US$ 5 527 777 con la VIP. La vacunación con la VIP permitiría evitar 64 AVAD con un costo de US$ 71 062 por AVAD evitado; evitar un caso de PPAV mediante la sustitución de la VOP por la VIP costaría entre US$ 1,8 millones y US$ 2,2 millones. CONCLUSIONES: La sustitución de la VOP por la VIP no es una medida efectiva en función del costo en Colombia, incluso si se sustituyera la vacuna celular contra la tos ferina, actualmente en uso, por una vacuna acelular combinada con una VIP.

OBJECTIVE: Evaluate the cost-effectiveness of introducing the injectable inactivated polio vaccine (IPV) in Colombia versus the current system based on the use of the oral vaccine (OPV). METHODS: A Markov model was designed, based on a hypothetical cohort of newborns that would receive the IPV or the OPV vaccine, with a two-year follow-up and monthly estimates of the number of cases of vaccine-associated paralytic poliomyelitis (VAPP) that would emerge. The cost was analyzed from the perspective of the insurer (costs throughout life) and society (cases of VAPP and disability-adjusted life years [DALYs] prevented). RESULTS: From 1988 to 1998, some 22.5 million doses of OVP were administered in Colombia and nine cases of VAPP were detected, for a rate of 4.0 ¥ 10-7 dose. According to the model, 2 to 4 cases of VAPP could be anticipated in the following two years. The cost of treating the VAPP cases would total US$302 008, with the cost of vaccination with OPV coming to US$737 037 and with IPV, US$5 527 777. Vaccination with IPV would prevent 64 DALYs, at a cost of US$71 062 per DALY prevented; preventing one case of VAPP by substituting OPV with IPV would cost between US$1.8 and US$2.2 million. CONCLUSIONS: Substituting OPV with IPV is not a cost-effective measure in Colombia, even if the cellular vaccine against whooping cough currently in use were replaced with an acellular vaccine combined with an IPV.

Vacunación antipoliomielítica en niños de la Ciudad de Buenos Aires / Antipoliomyelitic vaccination in children living in Buenos Aires City

A raíz de la presentación de un caso confirmado de poliomielitis paralítica por virus Sabin derivado (VSD) en niños de 15 meses se analizó la cobertura de vacunación antipoliomielítica en niños residentes en la Ciudad de Buenos Aires, durante el trienio 2006/2008. Se observó una mejora a lo largo del período analizado, pero sólo hubo valores superiores al 95 por ciento para la primera dosis. Aumentó la proporción de vacuna inactivada (IPV) en desmedro de la vacuna oral viva (OPV); en 2008, la cobertura con IPV primera dosis fue del 37,64 por ciento y del 19,48 por ciento para el ingreso escolar. La falta de inmunidad intestinal que se presenta en los niños vacunados con IPV, asociada a coberturas insatisfactorias condiciona un terreno propicio para la circulación de virus salvaje o VSD, lo cual favorece la aparición de casos de poliomielitis paralítica en niños no vacunados o inmunodeficientes.

Vacina contra poliomielite: um novo paradigma: [revisão] / Polio vaccines: a new paradigma: [review]

OBJETIVO: Analisar as estratégias propostas pela Organização Mundial da Saúde (OMS) para controle da poliomielite. FONTES DE DADOS: Levantamento das publicações sobre poliomielite indexadas no Medline, Lilacs e sites da OMS e Ministério da Saúde de janeiro de 2000 a dezembro de 2006. SÍNTESEDOS DADOS: O reconhecimento da paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral não deixa dúvidas de que, em breve, será necessário interromper o uso da vacina oral para poliomielite. Após os vírus selvagens serem erradicados, a vacina oral para poliomielite deverá ser interrompida, de preferência de forma sincronizada em todos os países. Após a interrupção da vacinação, as populações voltarão a ser suscetíveis à poliomielite, podendo ocorrer surtos da doença por vírus selvagens (escape dos laboratórios de forma acidental ou por bioterrorismo). Nos países que já utilizam a vacina para poliomielite com vírus inativado é pouco provável que haja interrupção da vacinação. Países que atualmente utilizam exclusivamente a vacina oral ficarão na dependência da vigilância epidemiológica e dos estoques de vacina oral para controlar eventuais surtos de pólio. Se a vacina oral para poliomielite for reintroduzida nessas populações, haverá novamente o risco de paralisia associada aos vírus vacinais e por vírus circulantes derivados da vacina oral, que podem se disseminar rapidamente para outras regiões e países vizinhos. CONCLUSÕES: É necessário planejar a introdução da vacina para poliomielite com vírus inativado no calendário de rotina brasileiro, assim como adquirir tecnologia para sua produção, que atualmente é insuficiente para as necessidades globais.

OBJECTIVE: Review the World Health Organization (WHO) strategies for poliomyelitis control. DATA SOURCES: Retrieval of publications on poliomyelitis indexed in Medline, Lilacs and in the WHO and Health Ministry sites, from January 2000 to December 2006. DATA SYNTHESIS: Acknowledgement of vaccine-associated paralysis and oral vaccine-derived circulating viruses' paralysis shall certainly require discontinuation of oral vaccination for poliomyelitis use in a short time. After eradication of the wild viruses, oral vaccination for poliomyelitis should be discontinued, preferably in a synchronized manner in all the countries. After termination of vaccination programs, people will become susceptible again to poliomyelitis virus and disease outbreaks caused by wild viruses may occur (accidental escape from laboratories or bioterrorism). In countries already using inactivated poliovirus vaccine, it is unlikely that vaccination will be interrupted. Countries that currently use exclusively oral poliovirus vaccine will have to rely on epidemiological surveillance and on oral vaccine inventories to control potential polio outbreaks. If the oral poliovirus vaccine is reintroduced in those populations, there will be again a risk for vaccine-associated paralysis and oral vaccine-derived circulating viruses' that may spread rapidly to other regions and to nearby countries. CONCLUSIONS: Inactivated poliovirus vaccine introduction in the routine Brazilian vaccination calendar should be programmed as well as acquisition of technology for inactivated poliovirus vaccine production since the latter is currently insufficient to cover global demand.