Vacinação universal contra hepatite A no Brasil: análise da cobertura vacinal e da incidência cinco anos após a implantação do programa / Universal hepatitis A vaccination in Brazil: analysis of vaccination coverage and incidence five years after program implementation

RESUMO: Introdução: Em 2014, o Brasil introduziu programa de imunização universal contra o vírus da hepatite A (HAV) para crianças no segundo ano de vida, por meio de dose única da vacina de vírus inativado. Este estudo teve como objetivo avaliar a cobertura vacinal (CV) contra o HAV no Brasil, diante da incidência de casos notificados cinco anos após a implantação do programa. Metodologia: Dados secundários foram obtidos pesquisando-se sítios eletrônicos de acesso livre do Ministério da Saúde, Departamento de Informática do Sistema Único de Saúde (DATASUS), para análise de incidência e CV. Resultados: A CV variou entre 60,13 e 97,07%. A homogeneidade da CV contra hepatite A nos estados ficou aquém da meta estabelecida. Após 2015, houve queda da CV em todas as regiões do país. Apesar da cobertura insuficiente, houve redução concomitante da incidência da hepatite A em todo o Brasil. A taxa de incidência caiu de 3,29 para 0,80/100 mil entre 2014 e 2018. No entanto, ocorreu diminuição da velocidade de queda da incidência entre 2017 e 2018, o que pode ser consequência dos percentuais insuficientes de CV. Esse fenômeno parece acompanhar tendência geral de enfraquecimento do esforço vacinal no país, verificado também para outras vacinas, como poliomielite e tríplice viral. Conclusão: Esses números sugerem a necessidade de esforços para melhorar as taxas de CV da hepatite A no país.

ABSTRACT: Introduction: In 2014, Brazil introduced a universal immunization program against the hepatitis A virus (HAV) for children in the second year of life, using a single dose of inactivated virus vaccine. The objective of this study was to evaluate the vaccination coverage (VC) against HAV in Brazil, against the incidence of cases reported five years after the implementation of the program. Methodology: Secondary data were obtained by searching free access electronic sites of the Ministry of Health, Department of Informatics of the Unified Health System (Departamento de Informática do Sistema Único de Saúde - DATASUS), for incidence analysis and VC from 2014 to 2018. Results: VC ranged from 60.13 to 97.07%. The homogeneity of VC against hepatitis A did not reach the established goal throughout all states but for a few exceptions. After 2015, CV decreased in all regions of the country. Despite insufficient coverage, a concomitant reduction in the incidence of Hepatitis A took place throughout the country. The incidence rate fell from 3.29 to 0.80/100,000 between 2014 and 2018. However, there was an interruption in the pace of incidence fall between 2017 and 2018, which may be a consequence of insufficient VC. This phenomenon seems to be part of a widespread downward trend in vaccination effort across the country, also verified for other vaccines, such as poliomyelitis and measles, mumps and rubella vaccine. Conclusion: These figures suggest the need for implementing efforts to improve hepatitis A VC rates in the country.

Initial evaluation of universal immunization with a single dose against hepatitis A virus in Central Brazil

ABSTRACT Vaccination against the hepatitis A virus (HAV) administered in two doses has been used effectively in universal child immunization programs in several countries. A single-dose vaccination was adopted in some low-income countries in an attempt to reduce costs without losing effectiveness. In 2014, single-dose universal vaccination was introduced in Brazil for children aged two years. Since such strategy is still not universally accepted, its efficacy should be compared to the two-dose strategy. To assess the humoral response after the single-dose HAV vaccination schedule, a cross-sectional study was conducted in Primavera do Leste, in Mato Grosso state, Central Brazil, including 265 children vaccinated through the National Immunization Program. Blood was collected by using a digital puncture and further applied to filter paper cards. Anti-HAV was detected in 218 out of 265 dried blood spots (DBS). Blood venous samples were collected from 34 out of 47 children who were not anti-HAV positive in DBS samples. Eighteen of them tested positive for anti-HAV, giving a final score of 93.6% (236/252) of seropositivity. In conclusion, this study demonstrated a high rate of anti-HAV positivity in the short term after single-dose hepatitis A vaccination in the population investigated. Moreover, the DBS was shown to be a reliable tool for detecting anti-HAV antibodies.

Opinión del Comité Consultivo de Inmunizaciones de la Sociedad Chilena de Infectología en relación a los brotes de hepatitis A en Chile / Statement of the Advisory Committee on Immunizations of Sociedad Chilena de Infectología about outbreaks of hepatitis A in Chile

Resumen El presente documento corresponde a la opinión del Comité Consultivo de Inmunizaciones de la Sociedad Chilena de Infectología, en relación a los brotes de hepatitis A en Chile. Las recomendaciones emitidas se basan en antecedentes epidemiológicos, características de la infección por virus hepatitis A(VHA) y en la experiencia mundial con las vacunas disponibles En relación a la infección por virus hepatitis A, Chile ha transitado de una endemia alta a una endemia intermedia, concentrándose actualmente los casos en personas mayores de 15 años, con brotes frequentes, uno de ellos este año causado por el genotipo 1A del VHA que se concentró en hombres que tienen sexo con hombres (HSH). La endemia actual, la presencia de brotes regulares, la frecuencia de desastres naturales en el país como terremotos e inundaciones sumado a la disponibilidad de vacunas eficaces, seguras y con estudios de costo efectividad locales, nos llevan a plantear medidas para el control de brotes, medidas focalizadas en grupos de riesgo y especialmente medidas a mediano y largo plazo, que incluyen la vacunación universal de niños contra esta enfermedad.

This document represents the position of the Chilean Infectious Diseases Society Advisory Committee on Immunization Practices regarding hepatitis A epidemiological situation in Chile. The recommendations are based on local epidemiological data, the hepatitis A virus infection characteristics and the global experience with the available vaccines. In relation to hepatitis A, Chile is no longer a highly endemic area but actually an intermediate one, currently concentrating cases in individuals over 15 years of age, with frequent outbreaks. In 2017 we have seen an important outbreak of genotype 1A in men who have sex with men (MSM). The current endemic, the presence of regular outbreaks, the frequency of natural disasters in Chile, together with the availability of safe, effective vaccines and local cost-effectiveness studies led us to propose measures for outbreak control for high risk groups protection and mid and long term, including a more definitive solution which is universal vaccination against this disease in small children.

Hepatitis A seroprevalence in public school children in Campos dos Goytacazes, Rio de Janeiro State, Brazil, prior to the introduction of the hepatitis A universal childhood vaccination / Soroprevalência da hepatite A em crianças de escolas públicas em Campos dos Goytacazes, Rio de Janeiro, Brasil, antes da introdução da vacinação infantil universal / Seroprevalencia de la hepatitis A en niños de escuelas públicas en Campos dos Goytacazes, Río de Janeiro, Brasil, antes de la introducción de la vacunación infantil universal

Abstract: This cross-sectional study was carried out between August 2011 and July 2012 in the city of Campos dos Goytacazes in Rio de Janeiro State, Brazil. Dried blood spot samples were collected on filter paper from 919 individuals between the ages of 1 and 19 and were tested for antibodies against the hepatitis A virus (anti-HAV). The total prevalence was 20.7%, while 94.7% of children under the age of 5 were found to be susceptible to HAV infection. The prevalence of anti-HAV increased with age, reaching 33.3% among individuals aged between 15 and 19, thereby indicating that this municipality has a low level of endemicity for hepatitis A. Age, non-white skin color, accustomed to swimming in the river and more than five people living at home were the factors that were associated with an increase in the chance of a positive anti-HAV result. Mother's education level (secondary or tertiary) was considered a protective factor for HAV infection. The data obtained showed that a large proportion of the children from Campos dos Goytacazes were at risk of HAV infection, which should be minimized with the introduction of the vaccination program against hepatitis A that was launched in the municipality in 2011.

Resumo: Estudo do corte transversal, realizado entre agosto de 2011 e julho de 2012 em Campos dos Goytacazes, Rio de Janeiro, Brasil. Amostras de sangue capilar em papel de filtro foram coletadas de 919 indivíduos com idade entre 1 e 19 anos e testadas para anticorpos para o vírus da hepatite A (anti-HAV). A prevalência total foi de 20,7% e 94,7% das crianças abaixo de 5 anos foi suscetível a infecção pelo HAV. A prevalência de anti-HAV aumentou com a idade, alcançando 33,3% entre indivíduos com 15 a 19 anos, caracterizando este município com um nível baixo de endemicidade para hepatite A. Idade, cor da pele não-branca, hábito de nadar no rio e número de moradores na residência acima de 5 foram associados com o aumento de chance de ser positivo para anti-HAV. O nível educacional materno (médio ou superior) foi considerado como fator de proteção para a infecção pelo HAV. Os dados obtidos mostraram que uma grande parte das crianças de Campos dos Goytacazes estava sob risco de infecção pelo HAV, o que deve ser minimizado com o programa de vacinação contra hepatite A implantado em 2011 no município.

Resumen: Estudio de corte transversal, realizado entre agosto de 2011 y julio de 2012 en Campos dos Goytacazes, Río de Janeiro, Brasil. Se recogieron muestras de sangre capilar en papel de filtro de 919 individuos con una edad entre 1 y 19 años y testadas para anticuerpos del virus de la hepatitis A (anti-HAV). La prevalencia total fue de un 20,7% y un 94,7% de los niños por debajo de los 5 años fue susceptible a la infección por el HAV. La prevalencia de anti-HAV aumentó con la edad, alcanzando un 33,3% entre individuos con 15 a 19 años, caracterizando este municipio con un nivel bajo de endemicidad para la hepatitis A. Edad, color de piel no-blanca, hábito de nadar en el río y un número de ocupantes en la residencia de más de 5 se asociaron con el aumento de oportunidad de ser positivo para anti-HAV. El nivel educacional materno (medio o superior) se consideró como un factor de protección para la infección por el HAV. Los datos obtenidos mostraron que una gran parte de los niños de Campos dos Goytacazes estaba bajo riesgo de infección por el HAV, lo que debe ser minimizado con el programa de vacunación contra la hepatitis A implantado en 2011 en el municipio.

Seroprevalence of hepatitis A immunity among brazilian adult patients with liver cirrhosis: is HAV vaccination necessary?

BACKGROUND: Patients with chronic liver disease have a higher risk of fulminant hepatitis when infected with hepatitis A virus, and vaccination of these patients against such infection is recommended. In Brazil, mainly in the South and Southeast regions, the epidemiology of hepatitis A (HA) has shifted from high to intermediate endemicity, which would have implication on policy of HA vaccination for these populations. OBJECTIVE: To verify the prevalence of HA immunity in adult patients with liver cirrhosis (LC), in Uberlândia MG, a city of Southeastern Brazil. METHODS: Between December 2005 and December 2006, 106 patients with LC were consecutively evaluated. In addition, 75 individuals without LC or alcoholism were evaluated (control group - CG). RESULTS: Total anti-HAV (ELISA methods) was positive in 104 (98.1 percent) patients with LC (82 men, 24 women; mean age, 53.3 ± 11.9 years) and in 74 (98.7 percent) individuals of the CG (55 men, 20 women; mean age, 47 ± 11.6 years), p > 0.05. CONCLUSIONS: For patients with chronic liver disease, in the geographic regions and age groups evaluated, routine vaccination against hepatitis A is not recommended. Moreover, the serum determination of total anti-HAV, used to assess immunity, is five times cheaper than vaccination against hepatitis A and, for this reason, should precede vaccination.

Hepatitis A en niños / Hepatitis A in children

La Hepatitis A (HVA), también llamada hepatitis infecciosa, transmitida por alimentos, epidémica,ictericia catarral o epidémica, entre otros, es una enfermedad producida por un agente viral que se trasmite por vía fecal oral y generalmente su curso es autolimitado, aunque, puede progresar ahepatitis fulminante ocasionando la muerte a una proporción pequeña de los infectados. Pertenece al géner o Hepatovir us de la Familia Picornaviridae. La HVA, tiene una distribución universal, aunque con grandes diferencias geográficas en cuanto a su prevalencia, ocurre en forma esporádica y epidémica en todo el mundo, con una tendencia a presentarse en ciclos. La HVA, tiene un periodo de incubación prolongado, entre 15 a 50 días, con un promedio de 29 días, lo que hace difícil relacionar los síntomas con algún alimento o bebida ingerida. El diagnostico de la HVA, se basa en la detección de anticuerpos contra el VHA tipo IgM e IgG. El tratamiento básicamente es de soporte, sintomático y en casos de falla hepática, el trasplante es la única opción. La inmunoglobulina confiere inmunidad pasiva a corto plazo mientras la vacuna provee una protección activa a largo plazo.

Hepatitis A (HVA), also called infectious hepatitis, foodborne, epidemic, or epidemic or catarrhaljaundice, among others, is a disease caused by a viral agent that spreads through fecal-oral routeand usually self-limited course, although fulminant hepatitis can progress to causing death to a small proportion of those infected. Is a Hepatovirus genus of the Picornaviridae Family. The HVA, has a worldwide distribution, but with large geographical differences in its prevalence, occurs in sporadic and epidemic worldwide, with a tendency to occur in cycles. The HVA, has a long incubation period between 15 to 50 days, with an average of 29 days, making it difficult to correlate symptoms with food or drink intake. The diagnosis of HVA was based on the detection of antibodies against HAV IgM and IgG.

Vaccination with a Human Papillomavirus (HPV)-16/18 AS04-Adjuvanted Cervical Cancer Vaccine in Korean Girls Aged 10-14 Years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr.

Hepatitis A: the costs and benefits of the disease prevention by vaccine, Paraná, Brazil

This study evaluated the epidemiological behavior of the hepatitis A in Paraná state and compared the costs of the disease and the vaccination. This is an epidemiological descriptive study including a pharmacoeconomy analysis. We collected information in the national database reported cases (SINAN), in the mortality information system (SIM) and in the hospital information system (AIH) among 2000/2003 (Paraná State Public Health Department). We estimated the probability of one cohort of children to acquire hepatitis A during their lifetime and the costs with their treatment. We compared those costs with the cost of vaccinating the children. 14,682 hepatitis A cases were registered during the period studied, and 12,102 (82.4 percent) occurred in the 0-15 years-old age group. The annual incidence in the general population was 37.5/100,000. We observed 20 deaths caused by this disease; 7 of those occurred by liver failure. The estimated costs with the disease included the hospital costs, liver transplantation, liver failure treatment, and laboratory tests were high. The price of the vaccine is 10 USD/dose. Two doses are necessary to get the protection. The results showed a positive cost - benefit relation when we vaccinate children. We save 2.26 USD in treatment for each dollar invested in the vaccine. Paraná record high number of hepatitis A cases each year. We confirmed the positive cost - benefit relation when we vaccinate children against hepatitis A, reducing suffering, hospitalization, death and social costs. Vaccination against hepatitis A should be recommended in the routine of immunization program in Paraná state.

Importancia de las vacunas contra los virus de las hepatitis A y B en Chile / Vaccines against hepatitis A and B in Chile

The mode of transmission and epidemiological approach for hepatitis A and B are different. However, both are preventable with vaccines whose efficacy and long lasting protection has been demonstrated. This review describes the secular tendency of both infections in Chile, their risk factors that have contributed to their persistence in the country and the interventions that have been carried out to reduce the disease burden. Although the vaccine for hepatitis B was incorporated to the immunization program in 2005, the vaccine for hepatitis A persists in the list of interventions that must be assumed with priority by the Ministry of Health. If Chilean health authorities pretend to reach the enteric disease indicators of developed countries, they must accelerate the epidemiological transition towards the elimination of hepatitis A.

High prevalence of hepatitis A virus antibody among Bangladeshi children and young adults warrants pre-immunization screening of antibody in HAV vaccination strategy.

Serum samples from 465 subjects aged between 1 and 25 years were tested for antibody against hepatitis A virus (HAV) [anti-HAV IgG and IgM] to determine the seroprevalence of HAV antibody and do a cost-benefit analysis for decision making about vaccination against HAV among the general population of Bangladesh. A high prevalence of anti-HAV (74.8%) was observed in the study population; the whole study population was found positive for anti-HAV by the age of 25 years. On performing the cost-benefit analysis, it was found that the cost for vaccination with screening for anti-HAV was almost three times cheaper than vaccination without screening. Thus, in the present socioeconomic condition of Bangladesh, a policy based on screening for HAV antibody before vaccination is recommended.

Immunogenicity and safety of live attenuated hepatitis A vaccine: a multicentric study.

OBJECTIVE: To evaluate immunogenicity and tolerability of single dose live attenuated injectable hepatitis A vaccine in four metropolitan cities of India. METHODS: Live attenuated hepatitis A vaccine was administered to 505 children aged 18 to 60 months in four centers across India. Immunogenicity of the vaccine was assessed by estimation of anti-HAV antibody titer at 6 weeks and 6 months following administration of the vaccine. Safety evaluation of the vaccine was also done during the visits. RESULTS: At 6 weeks, 480 subjects (95%) came for the follow-up and 411 (81.4%) subjects reported at the end of 6 months. The geometric mean titer (GMT) of anti-HAV antibody of the subjects who did not have the seroprotective titer at the baseline were assessed at 6 weeks and 6 months which was 81.04 mIU/ml and 150.66 mIU/ml respectively. At 6 weeks, 95.1 % seroconverted and at the end of 6 months, 97.9 % had seroconverted. Both solicited and unsolicited vaccine-induced local and systemic adverse events were insignificant at all the centers, except swelling and induration in a few. CONCLUSION: Live attenuated injectable hepatitis A vaccine was immunogenic and tolerable with minimal reactogenecity, in this study of single dose schedule. Safety profile was also satisfactory in the study population.

Current status of liver diseases in Korea: Hepatitis A / 대한간학회지

The seroprevalence of anti-HAV (hepatitis A virus) has been decreasing in Korea. The decrease in HAV infection in young adults has resulted in the reduction of individuals with protective antibody and an increase in hepatitis A in the adult population. The increase in HAV infection in adults will have an impact on the magnitude and severity of the disease. In Korea, symptomatic hepatitis A has been gradually increasing since the mid-1990s, with a tendency toward an increase in mean age and disease severity. The endemic genotype of HAV in Korea has been changing from genotype IA alone to a mixture of genotype IA and IIIA. Therefore, preventive measures including universal vaccination in infants and active immunization of the adult population should be considered.

Universal vaccination of children against hepatitis a in Chile: a cost-effectiveness study / La vacunación infantil universal contra la hepatitis a en Chile: análisis de la relación costo-efectividad

OBJECTIVE: To evaluate the healthcare and economic impact of routine hepatitis A vaccination of toddlers in Chile. METHODS: We used a dynamic model of hepatitis A infection to evaluate the impact of a two-dose vaccination program, administered at ages 12 and 18 months. The model incorporated the changing epidemiology of hepatitis A in Chile and the development of vaccine-induced herd immunity. Our analysis was conducted from the public payer perspective, and an estimation of the societal perspective was performed. Costs are expressed in 2005 U.S. dollars. RESULTS: Vaccination of toddlers rapidly reduced the healthcare burden of hepatitis A. In the base case (95 percent vaccination coverage, 100-year time horizon, 1 percent annual decrease in force of infection), the average number of infections fell by 76.6 percent annually, and associated deaths fell by 59.7 percent. Even at 50 percent coverage, the program reduced infection rates substantially. Routine vaccination of toddlers had economic as well as health benefits, saving $4 984 per life-year gained (base case scenario). The program became cost saving after 6 years, and its overall cost-effectiveness per life-year gained was largely unaffected by changes in disease-related costs, herd immunity, coverage rate, and annual decrease in force of infection. CONCLUSIONS: Routine vaccination of toddlers will reduce the rates of symptomatic hepatitis A and associated mortality. The two-dose schedule evaluated here will be less expensive than disease-related costs in the absence of vaccination from the sixth year of its implementation. These findings support the establishment of a routine vaccination program for toddlers in Chile.

OBJETIVO: Evaluar el impacto sanitario y económico de la vacunación sistemática de infantes contra la hepatitis A en Chile. MÉTODOS: Se empleó un modelo dinámico de hepatitis A para evaluar el impacto de un programa de vacunación de dos dosis administradas a los 12 y 18 meses. El modelo incorporó la epidemiología cambiante de la hepatitis A en Chile y la aparición de la inmunidad de grupo inducida por la vacuna. El análisis se realizó desde la perspectiva del financiador público y se hizo un estimado desde la perspectiva de la sociedad. Los costos se expresaron en dólares estadounidenses del año 2005. RESULTADOS: La vacunación de los infantes redujo rápidamente la carga de la hepatitis A para los servicios de salud. En la variante de base (cobertura de la vacunación: 95 por ciento; horizonte temporal: 100 años; reducción anual de la virulencia de la infección: 1 por ciento), el número promedio de casos se redujo anualmente en 76 por ciento y el número de muertes asociadas disminuyó en 59,7 por ciento. Incluso con una cobertura de vacunación de 50 por ciento, el programa redujo notablemente la tasa de infección. La vacunación sistemática de los infantes presentó beneficios económicos y sanitarios y ahorró US$ 4 984,00 por año de vida ganado (en el escenario base). El programa generó ahorros a partir del sexto año y la efectividad general en función del costo por año de vida ganado no se afectó por cambios en los costos relacionados con la enfermedad, la inmunidad de grupo, la cobertura de vacunación o la reducción anual de la virulencia de la infección. CONCLUSIONES: La vacunación sistemática de los infantes reduciría la tasa de hepatitis A sintomática y la mortalidad asociada. A partir del sexto año del programa, los costos de aplicar el esquema evaluado de dos dosis serían menores que los relacionados con la enfermedad si no se aplicara la vacuna. Estos resultados apoyan la implantación de programas de vacunación sistemática de infantes...

Cost-effectiveness of childhood hepatitis A vaccination in Argentina: a second dose is warranted

OBJECTIVES: To investigate the cost-effectiveness of childhood vaccination against hepatitis A in the five geographic regions of Argentina, and to determine whether adding a second dose to the current one-dose schedule would provide health gains justifying its added cost. METHODS: A Markov model was used to consider four immunization options for the 2005 birth cohort: (1) no vaccination; (2) vaccination at 12 months of age, (3) vaccinations at 12 and 72 months of age; or (4) vaccinations at 12 and 18 months of age. Hepatitis A costs and consequences were predicted over 50 years. The cost-effectiveness of first and second vaccine doses was assessed through a range of vaccine prices and assumptions regarding the duration of vaccine protection. Costs and health gains (measured in quality-adjusted life years) were adjusted to present values using a 3 percent annual discount rate. RESULTS: The one-dose vaccination policy is predicted to reduce each birth cohort member's 50-year probability of overt hepatitis A from 7.2 percent to 4.1 percent. A second dose would reduce the probability to between 2.0 percent and 2.2 percent. Vaccination at 12 months of age, at 12 and 72 months, or at 12 and 18 months would reduce cases among personal contacts by 82 percent, 87 percent, and 92 percent, respectively. The first vaccine dose would meet accepted standards of cost-effectiveness in each region, and reduce costs in the Northeast, Central, and South regions. Adding a second dose at age 18 months would be cost-effective in each region, and further reduce costs in the Cuyo region. If the duration of protection with one dose is less than anticipated, the second dose would be more cost-effective. CONCLUSIONS: Greater health gains are derived from the first than second hepatitis A vaccine dose. However, this analysis supports the cost-effectiveness of providing both first and second doses to Argentina's children.

OBJETIVOS: Investigar la efectividad en función del costo de la vacunación infantil contra la hepatitis A en las cinco regiones de Argentina y determinar si la adición de una segunda dosis al esquema actual de una dosis aumentaría los beneficios a la salud y si estos justificarían el costo adicional. MÉTODOS: Se empleó el modelo de Markov para valorar cuatro opciones de vacunación para la cohorte nacida en el año 2005: 1) no vacunar; 2) vacunar a los 12 meses de edad; 3) vacunar a los 12 y a los 72 meses; y 4) vacunar a los 12 y a los 18 meses de edad. Se estimaron el costo y las consecuencias de la enfermedad a 50 años. La efectividad en función del costo de la primera y la segunda dosis de la vacuna se calculó a partir de varios precios de la vacuna e hipótesis acerca de la duración de la protección. Los costos y los beneficios para la salud (medidos en años de vida ajustados por la calidad de vida) se ajustaron por los valores actuales utilizando una tasa de descuento anual de 3 por ciento. RESULTADOS: Se estima que la política de vacunación con una dosis reduciría la probabilidad de cada miembro de la cohorte de padecer hepatitis A sintomática en 50 años de 7,2 por ciento a 4,1 por ciento. Una segunda dosis reduciría esa probabilidad a 2,0 por ciento-2,2 por ciento. La vacunación a los 12 meses de edad, a los 12 y a los 72 meses, o a los 12 y a los 18 meses reduciría el número de casos entre los contactos personales en 82 por ciento, 87 por ciento y 92 por ciento, respectivamente. La primera dosis de la vacuna satisfaría los estándares aceptados de efectividad en función del costo en todas las regiones del país y reduciría los costos en las regiones Nordeste, Central y Sur. La aplicación de una segunda dosis a los 18 meses resultaría efectiva en función del costo en todas las regiones y reduciría adicionalmente los costos en la región de Cuyo. Si la duración de la protección con una dosis fuera menor de la esperada, la segunda dosis...

Immunizing children to protect against the increasing risk of hepatitis A in adolescents and young adults in South Korea.

We evaluated the CR326F strain (VAQTA) derived hepatitis A vaccine in Korean children and adolescents >2 years of age to consider a future immunization program. In our study, the pediatric two-dose regimen of VAQTA was found to be generally well tolerated and resulted in 100% (95% CI 94.8, 100.0) seroconversion after 2 doses. Immunizing children with the HAV vaccine routinely should be considered in South Korea, particularly in areas where recent outbreaks have occurred.

Should one vaccinate patients with chronic liver disease for hepatitis A virus in India?

BACKGROUND: Hepatitis A virus (HAV) vaccination is recommended worldwide for patients with chronic liver disease to prevent decompensation due to superinfection with HAV. India being endemic for HAV, the prevalence of pre-existing antibodies against HAV due to subclinical exposure to the virus in childhood among patients with chronic liver disease may be high and, therefore, vaccination may not be needed. However, little data are available on the prevalence of HAV antibody among patients with chronic liver disease in India. METHODS: All patients with chronic liver disease seen at Gastroenterology Center, Army Hospital R and R, New Delhi during the year 2002 and diagnosed to have either chronic liver disease were tested for the presence of IgG anti-HAV antibody in their sera (using a commercial ELISA kit). All patients with acute exacerbation or rapid deterioration of a preexisting chronic liver disease were separately studied for presence of IgM anti-HAV. In addition, a matched number of patients who attended the center due to diseases other than liver disease were also studied as controls. RESULTS: One hundred and eighty seven patients of chronic liver disease and 89 controls were studied. Mean age of these two groups was 38.6 and 42.1 years and 153 (81.8%) and 78 (87.6%) of them were males respectively. Etiology of chronic liver disease was HBV infection in 91(48.7%), HCV infection in 62 (33.2%), autoimmune chronic hepatitis in 3 (1.6%), PBC in seven (3.7%) and cryptogenic 24 (12.8%). Of these 179 (95.7%) patients tested positive for IgG anti-HAV. A total of 37 hospitalisations in 29 patients were noted during the study period due to acute exacerbation of pre-existing chronic liver disease. None of these were positive for IgM anti-HAV, while 28 were positive for IgG anti-HAV. Among the controls, 87 controls (94.6%) were positive IgG anti-HAV. The prevalence of anti-HAV positivity was similar among patients with various etiologies. CONCLUSION: Vaccination against HAV is not routinely required among patients with chronic liver disease in India as there is a very high prevalence of pre-existing antibodies in these patients. HAV superinfection as a cause of acute exacerbation of chronic liver disease was not seen in this.

Vacuna anti hepatitis A / Hepatitis A vaccine

La vacuna anti hepatitis A inactivada es una valiosa herramienta preventiva por su alta inmunogenicidad, inducción de memoria, eficacia y perfil de seguridad. Puede ser utilizada a partir de los 12 meses de vida con excelente seroconversión. Las diferentes vacunas son intercambiables entre sí facilitando su uso en salud pública. La mayor utilidad en países con endemia mediana como Chile está en su uso programático en cohortes y en el control de brotes epidémicos circunscritos. Además representa una estrategia alternativa a la inmunoglobulina normal en el manejo de contactos estrechos en el hogar y en instituciones cerradas. En este artículo se revisan in extenso las experiencias publicadas que fundamentan estas aseveraciones.

Cost-benefit analysis of hepatitis a vaccination in Thailand.

We constructed a decision model to simulate costs and benefits for persons in the context of hepatitis A prevention. Three strategies were compared: i) no intervention; ii) vaccination against hepatitis A without screening; iii) vaccination against hepatitis A for those susceptible after screening for anti-HAV. We divided the population into 3 age groups : 3-11 years, 12-18 years and 19-40 years. Data regarding the cost of treatment and vaccination were obtained from the King Chulalongkorn Memorial Hospital. Relevant probabilities were obtained from published literature and expert opinion. At the present incidence of hepatitis A infection, in all age groups examined, the net benefits of a universal no-intervention strategy were higher than those of either vaccination (intervention) strategy. The cost of vaccination without screening in the 3-11-year and 12-18-year groups would equal the benefit if the incidence rates amounted to approximately 138 and 212 infected individuals per 100,000, respectively, that of vaccination with screening at incidence rates of about 200 and 260 infected persons per 100,000, respectively. In the 19-40-year group, the cost incurred by vaccination either with or without screening would equal the benefit at an incidence rate above 450 infected individual per 100,000. For the benefits to outweigh the estimated vaccination costs at present the vaccine is still too expensive. The cost of vaccination without screening in the 3-11-year group would equal the benefit if the cost of vaccine was about 586 baht/2 doses (293 baht/dose), and about 500 baht/2 doses (250 baht/dose) in the 12-18-year group. Likewise, because of the cost of vaccine, it would not be cost-beneficial in the 19-40-year group both with and without screening, and neither would it be in the 3-11-year and 12-18-year groups including screening. According to current standards, under the conditions of the present study the benefit of hepatitis A vaccination administered to the general population between the age of 3 and 40 years in Thailand does not justify the expenses incurred. Major changes in hepatitis A incidence, anti-HAV seroprevalence, vaccine cost or the treatment outcome would be required to potentially render either intervention strategy cost beneficial.