Importancia de las vacunas en salud pública: hitos y nuevos desafíos / The importance of vaccines in public health: milestones and new challenges

La creación del Programa de Inmunizaciones en el mundo ha sido una de las estrategias de salud pública más valorada y que contribuye a la equidad. Este programa fue lanzado por la Organización Mundial de la Salud en 1974, posteriormente en el año 1977 fue implementado por la Organización Panamericana de la Salud para los países de la región de América y en Chile fue a partir de 1979, poniendo a disposición un esquema contra 6 enfermedades inmunoprevenibles. Es un programa de Bien Público de cobertura nacional, gratuito para toda la población objeto para cada una de las vacunas, que cuenta con respaldo político, independiente de los cambios de gobierno y con financiamiento nacional en un 100%. Uno de los pilares de éxito de los programas es lograr altas coberturas de vacunación. En el caso de sarampión, dado la alta tasa de reproducción del agente y su condición de enfermedad en fase de eliminación, se requieren coberturas superiores a 95%. Aunque el principal indicador indirecto de desarrollo del programa es la tercera dosis de vacuna contra DFT (Difteria, Pertussis acelular, Tétanos). Aunque han transcurrido 45 años de existencia de los Programas de Inmunización, cinco de las Enfermedades Inmunoprevenibles forman parte de las 10 principales amenazas para la salud mundial. El presente artículo desarrolla parte de la historia del Programa Ampliado de Inmunizaciones de América y de Chile desde su génesis, destacando la importancia de los 12 componentes mínimos que forman parte de las actividades del programa y los hitos que han demostrado el valor, los beneficios de la vacunación, relatando ejemplos como viruela, poliomielitis, sarampión. Por último, se señalan las amenazas y posibles estrategias de superación.

The creation of the Immunization Program in the world has been one of the most valued public health strategies and one that contributes to equity. This Program was launched by the World Health Organization in 1974, later in 1977 it was implemented by the Panamerican Health Organization for the countries of the Americas region and in Chile since 1979, making available a scheme against 6 immunopreventable diseases. It is a program of Public Good of national coverage, free for all the target population for each of the vaccines, which has political support, independent of changes in government and 100% national financing. One of the corner stone of success of the programs is to achieve high vaccination coverage. In the case of measles, given the high rate of reproduction of the agent and its disease condition in the phase of elimination, coverage of more than 95% its needed. Although the main indirect indicator of program development is the third dose of DPT (Difteria, Acellular Pertussis, Tetanus) vaccine. Although 45 years of the existence of Immunization Programs have passed, five of the Immunopreventable Diseases are part of the 10 main risks to world health. This article develops part of the history of the Expanded Program of Immunizations of America and Chile since its genesis, highlighting the importance of the 12 limited components that are part of the activities of the program and the milestones that have experienced the value, benefits of vaccination, such as smallpox, polio, measles. Finally, the threats and possible strategies for overcoming them are pointed out.

MMR2 vaccination coverage and timeliness among children born in 2004 - 2009: a national survey in Saint Lucia, 2015 / Cobertura de vacunación y respeto de los plazos de la segunda dosis de la vacuna triple viral en los niños nacidos en el período 2004-2009: encuesta nacional realizada en Santa Lucía en el 2015 / Cobertura e momento oportuno de vacinação da segunda dose da vacina tríplice viral em crianças nascidas em 2004-2009: pesquisa nacional em Santa Lúcia, 2015

ABSTRACT Objectives To more accurately determine coverage and timeliness of the second dose of measles-mumps-rubella vaccine (MMR2), while identifying factors associated with low MMR2 vaccination uptake among children in Saint Lucia. Methods A survey was conducted in October - November 2015 targeting children born in 2004 - 2009. At 86 preschools and primary schools, two children from each grade were randomly selected, yielding an effective sample of 836 children. Health records were reviewed to assess vaccination coverage and timeliness. Parents and/or guardians and principals of all 86 schools were interviewed regarding knowledge, attitudes, and practices related to vaccination. Results Of 767 children included, 75% were vaccinated with MMR2 (n = 572); 46.7% were vaccinated in a timely manner, i.e., by 5 years of age. Cohorts born in 2004, 2005, and 2008 reported the lowest proportion. 'Mothers as caregivers' was positively associated with timely MMR2 vaccination. Although 97% of principals surveyed considered vaccination important, 48.8% were not aware of national legislation requiring complete vaccination prior to school entry. Survey results concurred with the low MMR2 administrative coverage rates reported by Saint Lucia, much lower than the recommended 95%. Conclusions Based on the results of this survey, Saint Lucia's national immunization program has lowered the age of MMR2 to 18 months in 2016, increased advocacy with schools to enforce the school-entry law, and is working to vaccinate the cohorts of children who have not received timely MMR2.

RESUMEN Objetivos Determinar con mayor precisión la cobertura y el respeto de los plazos de vacunación de la segunda dosis de la vacuna contra el sarampión, la rubéola y la parotiditis (triple viral), al tiempo que se detectan los factores asociados con la baja aceptación de esa vacuna en Santa Lucía. Métodos En octubre y noviembre del 2015 se llevó a cabo una encuesta centrada en niños nacidos entre el 2004 y el 2009. En 86 centros preescolares y primarios se seleccionó al azar a dos niños de cada grado, lo que arrojó un tamaño real de la muestra de 836 niños. Se analizaron los registros de salud para evaluar la cobertura y el respeto de los plazos de vacunación. Se entrevistó a los padres o tutores y los directores de las 86 escuelas sobre conocimientos, actitudes y prácticas en materia de vacunación. Resultados De los 767 niños incluidos, el 75% fueron vacunados con la segunda dosis de la triple viral (n = 572); el 46,7% fueron vacunados a tiempo, es decir, a los 5 años de edad. La proporción más baja se dio en las cohortes nacidas en el 2004, 2005 y 2008. Se observó que las madres cuidadoras influían positivamente en el respeto de los plazos de vacunación de la segunda dosis de la triple viral. Aunque el 97% de los directores encuestados consideraba que la vacunación era importante, el 48,8% desconocía la legislación nacional que exige la vacunación completa antes de ingresar a la escuela. Los resultados de la encuesta estaban en consonancia con las tasas bajas de cobertura administrativa de la segunda dosis de la triple viral informadas por Santa Lucía, muy por debajo del 95% recomendado. Conclusiones Según los resultados de esta encuesta, el programa nacional de vacunación de Santa Lucía redujo la edad de la segunda dosis de la triple viral a los 18 meses en el 2016, aumentó las actividades de promoción en las escuelas para fomentar el cumplimiento de la ley que obliga a recibir la vacunación antes de ingresar a la escuela y está trabajando para vacunar a las cohortes de niños que no recibieron la segunda dosis de la triple viral en su debido momento.

RESUMO Objetivos Determinar com precisão a cobertura vacinal e o momento oportuno para ministrar a segunda dose da vacina tríplice viral (sarampo, caxumba e rubéola - SCR) e identificar os fatores associados à baixa utilização da vacina em crianças. Métodos Uma pesquisa direcionada a crianças nascidas de 2004 a 2009 foi realizada em Santa Lúcia em outubro e novembro de 2015. Em 86 unidades de ensino infantil e fundamental, duas crianças de cada série foram selecionadas aleatoriamente, constituindo uma amostra efetiva de 836 crianças. Dados sobre a cobertura e o momento oportuno de vacinação foram obtidos das fichas de saúde. Foram conduzidas entrevistas com os pais e/ou responsáveis e os diretores das 86 escolas sobre conhecimento, atitudes e práticas relacionadas à vacinação. Resultados Das 767 crianças incluídas na amostra, 75% foram vacinadas com a segunda dose de SCR (n = 572) e 46,7% receberam a vacina no momento oportuno (ou seja, até os 5 anos de idade). Observou-se menor proporção de vacinados nas coortes nascidas em 2004, 2005 e 2008. "Mães como cuidadoras" teve uma associação positiva com ministrar a segunda dose de SCR no momento oportuno. Apesar de 97% dos diretores entrevistados considerarem a vacinação importante, 48,8% desconheciam a legislação nacional que exige vacinação completa para a matrícula escolar. Os resultados reforçaram a baixa cobertura vacinal da segunda dose de SCR registrada em Santa Lúcia, bem inferior ao índice recomendado de 95%. Conclusões A partir dos resultados desta pesquisa, em 2016, o programa nacional de vacinação de Santa Lúcia reduziu para 18 meses a idade de administração da segunda dose de SCR, intensificou a recomendação para que as escolas cumpram com a legislação para matrícula escolar e está empenhado em vacinar as coortes de crianças que não receberam a segunda dose de SCR no momento oportuno.

Implementation research: reactive mass vaccination with single-dose oral cholera vaccine, Zambia

Objective:To describe the implementation and feasibility of an innovative mass vaccination strategy ­ based on single-dose oral cholera vaccine ­ to curb a cholera epidemic in a large urban setting.Method:In April 2016, in the early stages of a cholera outbreak in Lusaka, Zambia, the health ministry collaborated with Médecins Sans Frontières and the World Health Organization in organizing a mass vaccination campaign, based on single-dose oral cholera vaccine. Over a period of 17 days, partners mobilized 1700 health ministry staff and community volunteers for community sensitization, social mobilization and vaccination activities in 10 townships. On each day, doses of vaccine were delivered to vaccination sites and administrative coverage was estimated.Findings:Overall, vaccination teams administered 424 100 doses of vaccine to an estimated target population of 578 043, resulting in an estimated administrative coverage of 73.4%. After the campaign, few cholera cases were reported and there was no evidence of the disease spreading within the vaccinated areas. The total cost of the campaign ­ 2.31 United States dollars (US$) per dose ­ included the relatively low cost of local delivery ­ US$ 0.41 per dose.Conclusion:We found that an early and large-scale targeted reactive campaign using a single-dose oral vaccine, organized in response to a cholera epidemic within a large city, to be feasible and appeared effective. While cholera vaccines remain in short supply, the maximization of the number of vaccines in response to a cholera epidemic, by the use of just one dose per member of an at-risk community, should be considered

Fatores associados à vacinação contra influenza entre trabalhadores de saúde de um complexo hospitalar de Salvador / Factors associated with influenza vaccination among health care workers in a hospital complex in Salvador

INTRODUÇÃO: Embora a vacina influenza seja anualmente recomendada para todos trabalhadores de saúde, estudos revelam que a cobertura vacinal desse grupo frequentemente é baixa. Diferentes fatores podem influenciar a vacinação contra a influenza, sendo necessário utilizá-los a favor da ampliação da cobertura vacinal.OBJETIVO: Identificar fatores que influenciam a prática de vacinar-se contra influenza entre trabalhadores de saúde. MATERIAIS E MÉTODOS: estudo transversal, ocorrido num Complexo Hospitalar de Salvador, Bahia. Utilizou-se um questionário autoaplicável, e os modelos "Conhecimento, Atitudes e Práticas" (CAP) e "Health Belief Model" (HBM). A vacinação contra influenza em 2014 (autorreferida)representou a variável principal, e fatores sociodemográficos,histórico de outras vacinas,conhecimentos e atitudes constituíram variáveis independentes.Considerou-se haver "conhecimento adequado", quando 75,0% ou mais dos indivíduos julgaram determinada informação corretamente. As análises foram feitas por regressão logística no Stata, versão 13, utilizando-se o teste qui-quadrado ao nível de 5% de significância, odds ratio, e intervalos de confiança de 95%. O modelo multivariado foi ajustado por sexo, idade e profissão, sendo composto pelas variáveis com p valor igual ou inferior a 0,20 na análise bivariada. A verificação de modelos alternativos mais adequados foi feita por retirada retrógrada, utilizando-se como parâmetro o "Critério de Informação de Akaike" (AIC). RESULTADOS: A amostra foi de 755 indivíduos, destacando-se técnicos de enfermagem (41,4%),enfermeiros (15,2%) e médicos (14,7%).Predominaram trabalhadores do sexo feminino (82,5%), entre 19 e 39 anos (82,4%), com 5 anos ou menos de experiência (67,5%). A cobertura vacinal global foi de 61,5%, sendo a maior entre enfermeiros (69,0%) e a menor entre médicos (49,1%). Os principais motivadores da vacinação foram conhecer a recomendação da vacina para si (49,0%), confiar em vacinas no geral (41,6%) e na eficácia da vacina influenza (35,4%). Os principais desmotivadores foram esquecimento (37,3%), inconveniência de locais/horários (22,5%) e não saber da campanha (16,3%). A principal estratégia que facilitaria a vacinação foi vacinar os trabalhadores no seu próprio setor de trabalho (56,6%). O conhecimento foi adequado no julgamento de 9/16 das informações, com destaque para médicos (15/16) e enfermeiros (13/16). A maior adequação (94,6% de acerto)refere-se à indicação da vacina para todo trabalhador de saúde, e o conhecimento menos adequado foi sobre a incapacidade da vacina causar a influenza (32,0% de acerto). Os fatores associados à vacinação foram: conhecer que pessoas saudáveis também precisam se vacinar contra influenza (OR=3,15 ; IC95%: 1,74 - 5,71); saber que a vacina não protege por muitos anos (OR=2,08 ; IC95%: 1,30 - 3,33); e não ter medo dos efeitos adversos pós-vacinais (OR=1,93 ; IC95%: 1,26 - 2,95). CONCLUSÕES: a vacinação contra influenza é influenciada por onhecimentos,atitudes e questões organizacionais/operacionais.Medidas educativas e de desmistificação de questões relacionadas à influenza e à vacina, bem como ampliação de dias/horários e locais de vacinação de acordo com a conveniência dos trabalhadores de saúde, devem compor as estratégias voltadas à elevação da cobertura da vacina influenza neste grupo.

INTRODUCTION: Although the influenza vaccine is recommended annually for all health workers, studies show that vaccination coverage of this group is often low. Different factors can influence the vaccination against influenza, it is necessary to use them in favor of the expansion of vaccination coverage. GOAL: To identify factors that influence the practice of vaccination against influenza among health workers. MATERIALS AND METHODS: A cross-sectional study, which took place in a hospital complex in Salvador, Bahia. We used a self-administered questionnaire, and the models "Knowledge, Attitudes and Practices"(CAP) and "Health Belief Model"(HBM). Influenza vaccination in 2014 (self-reported) was the main variable, and sociodemographic factors, history of other vaccines, knowledge and attitudes were independent variables. Considered to be "appropriate knowledge" as 75.0% or more of subjects judged certain information correctly. Analyses were performed by logistic regression using Stata, version 13, using the chi-squared test at 5% significance, odds ratio, and 95% confidence intervals. The multivariate model was adjusted for sex, age and profession, being composed of the variables that had a pvalue less than or equal to 0.20 in the bivariate analysis. The verification of most suitable alternative models was performed by backward withdrawal, using as a parameter the "Akaike Information Criteria" (AIC). RESULTS: The sample consisted of 755 individuals, mainly nursing technicians (41.4%), nurses (15.2%) and physicians (14.7%). There was a predominance of female workers (82.5%), between 19 and 39 years (82.4%), with five years or less experience (67.5%). The global vaccination coverage was 61.5%, the highest among nurses (69.0%) and lowest among physicians (49.1%). The main motivators to get vaccinated were to know the recommendation of the vaccine for themselves (49.0%), trust in vaccines in general (41.6%) and in the effectiveness of influenza vaccine (35.4%). The main demotivating were forgetfulness (37.3%), inconvenience locations/times (22.5%) and not knowing the campaign (16.3%). The main strategy would facilitate the vaccination was to inoculate workers in their own work sector (56.6%)...

Measles Elimination Activities in the Western Pacific Region: Experience from the Republic of Korea

We describe the global status of measles control and elimination, including surveillance and vaccination coverage data provided by the World Health Organization (WHO). Since 2000, two doses of measles vaccine (MCV2) became recommended globally and the achievement of high vaccination coverage has led to dramatic decrease in the measles incidence. Our finding indicates that, in the Western Pacific Region (WPR), substantial progress has been made to control measles transmission in some countries; however, the measles virus continues to circulate, causing outbreaks. The Republic of Korea (ROK) experienced a series of resurgence of measles due to the importation and healthcare-associated transmission in infants, however overall incidence and surveillance indicators met the WHO criteria for measles elimination. The ROK was verified to be measles-free along with Australia, Mongolia, and Macau, China in 2014. One of the effective elimination activities was the establishment of solid keep-up vaccination system in school settings. The lessons learnt from the measles elimination activities in Korea may contribute to enhancing the surveillance schemes and strengthening of vaccination programs in member countries and areas of WPR.

Análisis descriptivo de los casos de gripe A (H1N1) notificados durante la pandemia de 2009 en la Región Sanitaria V de la Provincia de Buenos Aires, Argentina / Descriptive analysis of cases of Influenza A (H1N1) reported durig the pandemic of 2009 in the Health Region V of the province of Buenos Aires, Argentina

A partir de la transmisión sostenida del virus de Gripe A(H1N1) en distintos países, la Organización Mundial de la Salud declaró el comienzo de la primera pandemia de influenza del siglo XXI el 11de junio de 2009. En Argentina, la región sanitaria V de la provincia de Buenos Aires fue una de las primeras afectadas en todo el país. OBJETIVO:realizar un análisis descriptivo de las notificaciones registradas de los casos de Gripe A (H1N1) en dicha región hasta el 20 de septiembre de 2009. MÉTODO: se trabajó con fuentes secundarias. La confirmación de casos (PCR en tiempo real) fue realizada en instituciones autorizadas. Variables consideradas: casos sospechosos, confirmados y fallecidos, sexo, edad, municipios, antecedentes epidemiológicos, embarazadas, fecha de inicio de síntomas y circulación viral por semana epidemiológica. RESULTADOS: se registraron 1.332 notificaciones de casos sospechosos y 949 confirmados. El mayor número de confirmados se registró en los municipios de Gral. San Martín (94), San Isidro (90), Pilar (85) y Vicente López (80). Las semanas epidemiológicas 23, 24 y 25 registraron la mayor cantidad de casos confirmados. Los grupos de edad que más confirmados aportaron fueron: de 5 a 9 años (121), 1 a 4 (89) y 10 a 14 (75) (cuya mediana de edad fue de 30 años). Se registraron 64 casos confirmados fallecidos. La tasa más alta de mortalidad específica por grupo de edad correspondió a menores de un año. Se registraron 9 casos confirmados en embarazadas y una puérpera, 5 de ellas fallecieron. CONCLUSIÓN: todos los municipios presentaron casos confirmados y 11 reportaron fallecidos. El pico de la epidemia se adelantó en una semana al registrado a nivel nacional y la mediana de edad en fallecidos fue más baja que la de todo el país. El análisis de mortalidad mostró un mayor riesgo para varones, embarazadas y menores de un año.

From the sustained transmission of influenza virus A (H1N1) in different countries, the World Health Organization declared the beginning of the first influenza pandemic of the twenty first century on June 11, 2009. In Argentina, the Health Region V of the Province of Buenos Aires was one of the first affected across the country. OBJECTIVE: to conduct a descriptive analysis of notifications of cases of Influenza A (H1N1) in that region until September 20, 2009. METHODS: we worked with secondary sources. The confirmation of cases (real-time PCR) was carried out in authorized institutions. Variables considered: suspected cases, confirmed and diseased, sex, age, municipalities, epidemiological history, pregnant, date of on set of symptoms and viral movement by epidemiological week. RESULTS: there were 1.332 notifications of suspected cases and 949 confirmed. The highest number of confirmed cases was in the municipalities of Gral. San Martin (94), San Isidro (90),Pilar (85) and Vicente López (80). The epidemiological weeks 23,24 and 25 showed the highest number of confirmed cases. Giventhe age group, which contributed more confirmed cases was that of 5-9 years (121), followed by 1-4 (89) and 10-14 (75). The median age was 30 years. There were 64 confirmed cases dead. The high estrate of cause-specific mortality by age group accounted for less than one year. There were nine conf irmed cases in pregnant and puerperal women, five of them died. CONCLUSION: all municipalities had confirmed cases and 11 confirmed deaths reported. The peak of the epidemic one week a head of the national and the medianage was lower than the registered for the rest of the country. The analysis of mortality showed a higher risk for men, pregnant women and children under one year.

Esquema nacional de vacunación: Documento de promoción de la norma técnica de salud Nº 080-MINSA/DGSP V.01 / National vaccination program: Document the promotion of health technical standard V.01 No. 080-MINSA/DGSP

El presente documento proporciona a los profesionales y técnicos de salud la información necesaria y clave sobre los aspectos generales y específicos que establece la norma técnica de salud para la administración, aplicación, monitoreo y supervisión del esquema de vacunación en los ámbitos central, regional y local

Polio eradication in India: the way forward.

Despite remarkable decline in the number of poliomyelitis cases, the dream of polio eradication in India remains elusive. This is despite considerable effort and expenditure for well over a decade. Various reasons have been cited for this and interventions implemented accordingly. None of these seem to have borne fruit. It is appropriate to have a relook at the polio eradication strategies in order to learn from past errors and determine a feasible solution to achieve the goal. This article examines important tissues that hamper the eradication effort and proposes a way forward.

Vacunas del programa nacional PAI 2006: ¿qué hay de nuevo ? / National program vaccines PAI 2006: what's new?

Los progresos en mejorar y desarrollar nuevas estrategias en el Programa Nacional de Inmunizaciones (PAI), han sido muy significativos en los últimos años y aún queda mucho por realizar especialmente en la necesidad de ir incorporando nuevas vacunas, como la anti-hepatitis A o racionalizando el programa pensando en cubrir algunas enfermedades en adolescentes y adultos, o cambiando a vacunas con mayor desarrollo tecnológico como es la anti-pertussis acelular. Se han mejorado coberturas, incorporando nuevas vacunas, como la anti-hepatitis B y se han retirado refuerzos que hoy en día resultan innecesarios, como la BCG en la edad escolar. Se analizan los progresos y el conocimiento actualizado de cada una de las vacunas incorporadas al PAI, Chile 2006.

Child survival and safe motherhood program in Rajasthan.

OBJECTIVE: This study was planned to evaluate the MCH services, particularly immunization in rural areas of the poor-performing state of Rajasthan. METHODS: A community-based, cross-sectional survey using the WHO 30 cluster technique was carried out as a field exercise by participants of 9th Field Epidemiology Training Programme (FETP) course by National Institute of Communicable Diseases (NICD) in rural areas of Alwar district of Rajasthan. RESULTS: Less than one third (28.9%) of children, aged 12-23 months, were fully immunized with BCG, 3 DPT, 3 OPV and Measles vaccines; around a quarter (26.5%) had not received even a single vaccine (non immunized), and little less than half (44.5%) were found partially immunized. Around half of the eligible children were vaccinated for BCG (55.9%) and Measles (43.6%). Though nearly two-third (66.8%) were covered with first dose of DPT and OPV, but about one third of these children dropped out of third dose of DPT and OPV for various reasons. National Family Health Survey (NFHS) data also had revealed that BCG coverage was 64.3%; measles was 36.2%; and coverage by DPT 1, 2, 3 and Polio 1,2 and 3 were 64.4%, 57.0%, 46.6% and 77.5%, 71.1% and 54.4% respectively in rural areas. The main reasons for drop-out or non-immunization was "lack of information about the immunization programme" (41.3%). Though nearly all (more than 96%) of the children were immunized through Government established centers, but immunization cards/documents were made available only to 27.6% of children. CONCLUSION: The problem of low coverage and high drop-out rate of immunization could be overcome by creating awareness of the program and relevance of 2nd and 3rd doses of DPT and polio vaccines. Increasing community participation through intensive and extensive health education campaign should also be undertaken. Since most of the deliveries were done at home under the supervision of untrained midwives, training programme as well as involving them in IEC activities should be contemplated.

Polio eradication in India: current status.

India has reached the final stage of polio eradication. The polio partnership in India, under the leadership of the Government of India, mounted tremendous response to the outbreak. The progress since 2003 is the most significant in the history of polio eradication in India. Surveillance sensitivity was increased to reach the goal for polio eradication. Since nearly all polio cases now occurring in India are caused by type 1 poliovirus in children, monovalent oral polio vaccine type 1 (mOPV1) was introduced in select high-risk districts of UP, Bihar and Mumbai-Thane during the April and May 2005 National Immunisation Days and the June and August 2005 in 6 sub-national immunisation rounds. Strategies were also being implemented to improve the impact of supplementary immunisation activities in the high-risk areas. As a result of supplementary immunisation activities targeted using surveillance data, India has made striking progress towards polio eradication.

Routine immunisation in India.

Vaccine preventable diseases have been reduced in the country since the routine immunisation programme started in 1978 as the Expanded Programme on Immunisation, then in 1985 renamed as Universal Immunisation Programme. Re-emergence of some vaccine preventable disease is a concern to all and the Government of India has launched a new multiyear plan to strengthen the routine immunisation. A number of recommendations was made to address the weaknesses in the programme. Some newer initiatives were also made under the multiyear plan and National Rural Health Mission to strengthen the routine immunisation. The general practitioners can play a positive role while immunising children as per Universal Immunisation Programme. Routine immunisation is one of the key components of polio eradication.

Understanding and addressing childhood immunization coverage in urban slums.

The National Population Policy (2000) aims at complete protection of all children against vaccine preventable diseases by 2010. Urban poor, many residing in slums, comprise about one fourth of India's 285 million urban population. 60% of the children aged 12-23 months in urban India are fully immunized; coverage among urban poor children is a dismal 43%. The inter state variations of immunization coverage in urban areas, reveals a service coverage gap which calls for a rethink on resource allocation and strengthening processes to improve immunization coverage amongst urban poor. Debilitating environmental conditions and high population density in slums expedite disease transmission. Comparisons of urban rural disease incidence indicate a particular urban risk for vaccine preventable diseases. This paper attempts to understand the current scenario and challenges in improving immunization coverage in urban slums; immunization being one of the most successful public health interventions of the past century. It also discusses possible mechanisms for effectively reaching the often left out urban poor. Coordinated activities by the multitude of providers, accurate information based outreach, effective monitoring and community enablement to demand quality services are critical for improving utilization of immunization services by a heterogeneous urban poor population.

Rate of hepatitis B seropositivity following mass vaccination in the Islamic Republic of Iran

Universal vaccination of all neonates against hepatitis B virus has been implemented in the Islamic Republic of Iran since 1993. To evaluate the efficacy of the programme, 2 large seroepidemiologic surveys were conducted before and after mass vaccination on a representative sample of 1/1000 of the population. The overall seropositivity rate showed no significant decline between 1991 and 1999 but in the age group 2-14 years the rates reduced significantly [1.3% versus 0.8%, P < 0.05]. Interestingly, we observed a significantly higher decline in hepatitis B virus carrier rate in rural [1.5% versus 0.6%] than urban areas [1.1% versus 0.9%]. Universal vaccination significantly decreased the carrier rate among young children in this country