[Cost-effectiveness of universal childhood vaccination against hepatitis A in Spain: a dynamic approach]. / Coste-efectividad de la vacunación universal infantil frente a la hepatitis A en España: un enfoque dinámico.

OBJECTIVE: To evaluate the cost-effectiveness of infant universal vaccination against hepatitis A in Spain. METHOD: Using a dynamic model and decision tree model, a cost-effectiveness analysis was performed to compare three vaccination strategies against hepatitis A: non-vaccination strategy versus universal childhood vaccination of hepatitis A with one or two doses. The perspective of the study was that of the National Health System (NHS) and a lifetime horizon was considered. Both costs and effects were discounted at 3% per year. Health outcomes were measured in terms of quality adjusted life years (QALY) and the cost-effectiveness measure used was the incremental cost-effectiveness ratio (ICER). In addition, deterministic sensitivity analysis by scenarios was performed. RESULTS: In the particular case of Spain, with low endemicity for hepatitis A, the difference in health outcomes between vaccination strategies (with 1 or 2 doses) and non-vaccination are practically non-existent, terms of QALY. In addition, the ICER obtained is high, exceeding the limits of willingness to pay from Spain (€22,000-25,000/QALY). The deterministic sensitivity analysis showed that the results are sensitive to the variations of the key parameters, although in no case the vaccination strategies are cost-effective. CONCLUSIONS: Universal infant vaccination strategy against hepatitis A would not be a cost-effective option from the NHS perspective in Spain.

Actualización sobre hepatitis A

Introducción: La hepatitis es una enfermedad inflamatoria que afecta al hígado. El virus de la hepatitis A produce un cuadro infeccioso agudo por lo general autolimitado en el ser humano, para el cual no existe tratamiento específico. Objetivo: Realizar una actualización acerca del comportamiento y manejo actual de la infección por el virus de la hepatitis A. Métodos: Se realizó una revisión bibliográfica durante septiembre y octubre de 2021, se consultaron 156 artículos en idioma inglés y español de bases de datos como SciELO, PubMed, LILACS y Medigraphic, de ellos se utilizaron 30 citas. Se empleó la combinación de términos y operadores booleanos y métodos teóricos como: análisis-síntesis, inducción-deducción e histórico-lógico. Resultados: Se abordó el comportamiento de la infección causada por el virus de la hepatitis A, se hizo hincapié en su epidemiología, características morfológicas y funcionales que permiten su infectividad, evolución y manifestaciones clínicas, complicaciones, tratamiento y perspectivas actuales. Conclusiones: El virus de la hepatitis A produce un cuadro infeccioso agudo. Se presenta tanto de forma esporádica como epidémica. Es la forma más común de hepatitis viral aguda. La transmisión es de persona a persona por vía fecal oral. Los síntomas relacionados con las hepatitis virales agudas son variables e inespecíficos. El diagnóstico de certeza se realiza mediante las pruebas serológicas y técnicas de biología molecular para la identificación del virus. No existe tratamiento específico para esta infección.

Introduction: Hepatitis is an inflammatory disease that affects the liver. The hepatitis A virus produces a generally self-limited acute infectious picture in humans, for which there is no specific treatment. Objective: To update on current behavior and management of hepatitis A virus infection. Methods: A bibliographic review was carried out during September and October 2021, consulting 156 articles in English and Spanish from databases such as SciELO, PubMed, Lilacs and Medigraphic, of which 30 citations were used. The combination of Boolean terms and operators and theoretical methods such as: analysis-synthesis, induction-deduction and historical-logical was used. Results: The behavior of the infection caused by the hepatitis A virus was addressed, emphasizing its epidemiology, morphological and functional characteristics that allow its infectivity, evolution and clinical manifestations, complications, treatment and current perspectives. Conclusions: The hepatitis A virus produces an acute infectious picture. It occurs both sporadically and epidemically. It is the most common form of acute viral hepatitis. Transmission is person-to-person by the fecal oral route. Symptoms related to acute viral hepatitis are variable and nonspecific. The diagnosis of certainty is carried out by means of serological tests and molecular biology techniques for the identification of the virus. There is no specific treatment for this infection.

Prevalence of indications for adult hepatitis A vaccination among hepatitis A outbreak-associated cases, Three US States, 2016-2019.

BACKGROUND: Safe and effective hepatitis A vaccines have been recommended in the United States for at-risk adults since 1996; however, adult vaccination coverage is low. METHODS: Among a random sample of adult outbreak-associated hepatitis A cases from three states that were heavily affected by person-to-person hepatitis A outbreaks, we assessed the presence of documented Advisory Committee on Immunization Practices (ACIP) indications for hepatitis A vaccination, hepatitis A vaccination status, and whether cases that were epidemiologically linked to an outbreak-associated hepatitis A case had received postexposure prophylaxis (PEP). RESULTS: Overall, 74.1% of cases had a documented ACIP indication for hepatitis A vaccination. Fewer than 20% of epidemiologically linked cases received PEP. CONCLUSIONS: Efforts are needed to increase provider awareness of and adherence to ACIP childhood and adult hepatitis A vaccination and PEP recommendations in order to stop the current person-to-person hepatitis A outbreaks and prevent similar outbreaks in the future.

The Safety, Immunogenicity, and Immunopersistence of Hepatitis A Vaccine in HBs-Ag-Positive Participants: A Retrospective Study.

Objectives: To compare the safety, immunogenicity, and immune persistence of hepatitis A (HA) vaccines between HBs-Ag-positive and -negative participants. Method: 9000 participants were enrolled in the phase IV study of live attenuated HA (HA-L) or inactivated HA (HA-I) vaccines. The HBs-Ag-positive subjects were detected and became an independent observation group. Adverse reactions (ARs), geometric mean concentrations (GMCs) and seroconversion rates (SRs) of the vaccines were analyzed at five time points until three years after vaccination. Results: 120 HBs-Ag-positive subjects were screened out, only 1 participant had grade 1 experienced ARs after HA-L injection. Except the time point of two years, the SRs of HBs-Ag-positive group were 100% for both vaccines. The GMCs were not statistically different between HBs-Ag-positive and -negative groups after the HA-L vaccination. The logarithmically transformed GMCs for HBs-Ag-positive and -negative groups were 3.21 mIU/mL (95% CI, 2.03-4.39 mIU/mL) and 2.95 mIU/mL (95% CI, 2.88-3.02 mIU/mL) 28 days after the HA-L vaccination, respectively. Conclusions: Both HA-L and HA-I vaccines were safe for HBs-Ag-positive participants and may provide an excellent long-term protection against HAV in this study. The results indicated that people positive or negative for HBs-Ag can receive both HA-L and HA-I vaccines (ClinicalTrials.gov number, NCT02601040).

Short-term immunogenicity and safety of hepatitis-A and varicella vaccines in HIV-exposed uninfected and HIV-unexposed South African children.

BACKGROUND: HIV-exposed uninfected (HEU) children have increased risk of infectious morbidity during early childhood. We evaluated the short-term immunogenicity and safety of single dose inactivated hepatitis-A virus (HAV) vaccine and live attenuated varicella zoster virus (VZV) vaccine in South African children. METHODS: 195 HIV-unexposed and 64 HEU children received either one dose of HAV or VZV vaccine at 18 months of age. Blood samples were tested for hepatitis-A or VZV antibodies before and one month after vaccination by chemiluminescent microparticle immunoassay and enzyme-linked immunosorbent assay, respectively. All children were evaluated for solicited adverse events (AEs). RESULTS: One-month post-vaccination, a similar percentage of HIV-unexposed (91.8%) and HEU (82.9%) children were seropositive for hepatitis-A (p = 0.144). VZV antibody geometric mean fold-rise was also similar in HIV-unexposed (5.6; 95%CI: 4.6-6.7) and HEU children (5.1; 95%CI: 3.7-7.2); however, only 44% HIV-unexposed and HEU seroconverted (titers > 50 mIU/ml). AEs occurred with similar frequency and severity between groups, except for more systemic AEs after VZV vaccination in HEU than HIV-unexposed children. CONCLUSIONS: Single dose HAV and VZV vaccine was similarly immunogenic in HIV-unexposed and HEU children. We did not identify differences in short-term humoral immunity after administration of either a live attenuated or inactivated vaccine. Seroconversion rates after a single dose of VZV vaccine were, however, lower compared to reports from previous studies (85-89%). CLINICAL TRIALS REGISTRATION: NCT03330171.

The impact of universal live attenuated hepatitis A vaccines in Henan, China, 2005-2018.

OBJECTIVES: To analyze the effects of one dose of live attenuated hepatitis A vaccine in a developing country. METHODS: The reported cases of hepatitis A virus (HAV) infection from 2005 to 2018 in Henan province, China, were analyzed. Data of vaccinated children were assessed on the childhood immunization information management system. Questionnaire survey and blood sample collection were randomly conducted in six counties and districts of Henan province to analyze the prevalence of HAV lgG among the population aged 0-70 years. RESULTS: In 2008, Henan province began to expand its program on immunization, and children aged 18 months were given one dose of live attenuated hepatitis A vaccine (HepA-L). From 2005 to 2007, the HAV incidence remained steady at above 5000 cases per year and increased to 7489 in 2007. Since 2008, the HAV incidence decreased cumulatively from 4576 to 237 in 2018, indicating a 94.8% decrease, which was particularly pronounced among adolescents (98.2%). The proportion of hepatitis A cases in patients younger than 10 years continually decreased from 41.6% in 2012 to 3.8% in 2018. The reduction of reported cases older than 40 years was slower than that of children. In 2012, the proportion of hepatitis A cases older than 40 years was 27.6%, and continually increased to 69.2% (164/237) in 2018. The results of serological investigation showed that the 0-1.5-year age group had the lowest anti-HAV IgG prevalence (38.6%), which increased to 75.0% in the 4-6-year age group, covered by this immunization program. CONCLUSIONS: The data indicated a large decrease in HAV infections in Henan province from 2008 onward in response to the introduction of a planned immunization program of HepA-L.

Hepatitis A vaccine immunogenicity in patients using immunosuppressive drugs: A systematic review and meta-analysis.

INTRODUCTION: Inactivated hepatitis A (HepA) vaccines are very immunogenic in healthy individuals; however, it remains unclear how different immunosuppressive regimens affect HepA vaccine immunogenicity. Our objective was to summarise the current evidence on immunogenicity of HepA vaccination in patients using immunosuppressive drugs. METHODS: We systematically searched the literature for studies on immunogenicity of inactivated HepA vaccines in adults using immunosuppressive drugs. Studies reporting seroconversion rates (SCR) 4-8 weeks after 1 and 2 doses of HepA vaccine in organ transplant recipients and patients with chronic inflammatory conditions were included in a meta-analysis. RESULTS: We included 17 studies, comprising 1,332 individuals. In healthy controls (2 studies), SCRs were 90-94% after the first dose and 100% after the second dose. In organ transplant recipients, SCRs ranged from 0 to 67% after the first dose of vaccine and 0-97% after the second dose. In patients with chronic inflammatory conditions, SCRs ranged from 6% to 100% after the first dose and from 48 to 100% after the second dose of vaccine. Patients using a TNF-alpha inhibitor versus conventional immune-modulators (e.g. methotrexate, azathioprine, corticosteroids) were more likely to seroconvert after the first dose of vaccine (OR12.1 [2.14-68.2]) but not after the second dose of vaccine (OR 0.78 [0.21-2.92]) in a meta-analysis. CONCLUSION: Studies evaluating HepA vaccine immunogenicity in immunosuppressive agents are heterogeneous. Overall, there is an impaired immune response following HepA vaccination in patients using immunosuppressive drugs, especially after only one dose of vaccine and in organ transplant recipients. HepA vaccination should therefore be considered before immunosuppressive therapy. Future research should focus on alternative vaccination regimens and long-term immunogenicity. PROSPERO ID: CRD42018102607.

Impact of the single-dose universal mass vaccination strategy against hepatitis A in Brazil.

Universal vaccination of children against hepatitis A was introduced in 2014 in Brazil as a single-dose schedule. We analyzed the numbers of reported cases of hepatitis A virus infection (HAV) from 2010 to 2017 to evaluate the initial impact of that intervention. Data were assessed and has been freely available on the Brazilian Ministry of Health website. The HAV incidence was steady around 6000 cases per year until 2014. Between 2014 and 2016, there was a 85.5% cumulative drop, independent of gender and geographical macroregions. The fall was especially significant among toddlers (96.8%). In 2017, cases increased due to an outbreak among male adults in São Paulo. Decrease in incidence continued to occur for females and for those under 15 years of age. Data show that there was a significant decrease in HAV cases number in Brazil from 2015 after the introduction of single-dose HAV vaccine program.

Long-term immunogenicity and immune persistence of live attenuated and inactivated hepatitis a vaccines: a report on additional observations from a phase IV study.

Both live attenuated (HA-L) and inactivated (HA-I) hepatitis A vaccine were licensed for routine use in China. Although phase 1, 2 and 3 clinical studies of both vaccines have been completed, further systematic evaluation of their immunogenicity and immunological persistence under phase 4 clinical studies in a wide range of conditions and involving large populations is necessary. A phase IV clinical trial (NCT02601040) was performed in 9000 participants over 18 months of age. Geometric mean concentrations (GMCs) and seroconversion rates (SRs) were compared at five time points during 3 years for 1800 individuals among them. The SRs of HA-L and HA-I were 98.08% (95% CI 95.59%-99.38%) and 99.64% (95% CI 98.93%-100.00%) respectively 28 days after administration of the first dose, and remained at 97.07% (95% CI 94.31%-98.73%) or above and 96.73% (95% CI 94.07%-98.42%) or above respectively during the following 3 years. The GMCs for both the HA-L and HA-I groups showed that both vaccines elicited high anti-HAV titres, considerably more than the threshold of protection needed against HAV infection in humans, and these titres were sustained. Hence, both HA-I and HA-L vaccines could provide an excellent long-term protective effect, and supported the routine use of both vaccines.

[Prevalence of hepatitis A antibody among population covered by different hepatitis A immunization strategies in Shandong Province, 2015, China].

Objective: To evaluate prevalence of hepatitis A antibody (anti-HAV IgG) among population covered by different hepatitis A vaccine immunization strategies in Shandong Province in 2015. Methods: In October 2015, according to the geographical location of Shandong Province, the stratified random sampling method was used to stratify the 17 municipal distrcts, and the random number table method was used for sampling, First, two eastern cites (Qingdao, Rizhao), two western cities (Liaocheng, Zaozhuang) and three central cities (Jinan, Zibo and Laiwu) were selected; secondly, one county was drawn from each city. Finally, the participants were divided into five age groups including ≤7 years (age group covered by free hepatitis A vaccination strategy), 8-11 years (age group who receive hepatitis A vaccination at their own charge), 12-24 years (age group covered by catch-up vaccination of hepatitis A), 25-34 years (age group born before hepatitis A vaccine was used) and ≥35 years (age group born before hepatitis A vaccine was used). After all the paticipants or their guardians asked and registered basic information such as age, gender, home address, blood samples were collected from them and anti-HAV IgG was detected by ELISA method. The positive rate of anti-HAV IgG and 95%CI were calculated. Results: A total of 1 654 participants were involved in the final analysis, including 856 males (51.75%) and 798 females (48.25%) whose mean age was (13.44±13.06) years. The crude positive rate of anti-HAV IgG was 91.41% (1 512/1 654, 95%CI: 89.96%-92.72%) and the age-adjusted rate was 90.93% (95%CI: 90.92%-90.94%). The positive rates of anti-HAV IgG was at the highest level in the age group of ≤7 years (95.90%, 95%CI: 95.88%-95.91%) and was at the lowest level in the age group of 25-34 years (83.23%, 95%CI: 83.21%-83.25%). The age-specific positive rates of anti-HAV IgG in eastern areas (96.79%, 95%CI: 96.78%-96.80%) were higher than those in both middle areas (86.66%, 95%CI: 86.65%-86.67%) and western areas (91.96%, 95%CI: 91.95%-91.97%). Conclusion: The positive rate of anti-HAV IgG was high among the general population in Shandong Province, but relatively low among young and middle-aged adults. Besides the routine immunization of hepatitis A among the children, more efforts should be taken for the prevention and control of hepatitis A among young and middle-aged adults in Shandong Province, especially in central and western areas.

Reappraisal of the Immunogenicity and Safety of Three Hepatitis A Vaccines in Adolescents.

Although the overall incidence of hepatitis A in Korea has been decreasing, adolescents remain highly vulnerable to its outbreaks. This study was conducted to compare the immunogenicity and safety of three hepatitis A vaccines in Korean adolescents. Healthy anti-hepatitis A virus seronegative subjects aged 13 to 19 yr were randomized in three equal groups to receive two doses of Avaxim™, Epaxal®, or Havrix®, 6 to 12 months apart. Seroconversion rates one month after the first dose were 98%, 95%, and 93% for Avaxim™, Epaxal®, and Havrix®, respectively. Seroconversion rates reached 100% for all vaccine groups one month after the second dose. Anti-HAV geometric mean concentrations (GMCs) were 7,207.7 mIU/mL (95% CI, 6023.1-8684.7), 1,750.5 mIU/mL (95% CI, 1362.9-2248.3), and 1,953.5 mIU/mL (95% CI, 1459.4-2614.7) after two doses of Avaxim™, Epaxal®, and Havrix® respectively. Avaxim™ was significantly more immunogenic than Epaxal® and Havrix®, whereas there were no significant differences in antibody responses between Epaxal® and Havrix®. Local and systemic solicited adverse events (AEs) were mostly of mild-to-moderate intensity and resolved within 5 days. No serious AEs were reported. In conclusion, all three vaccines are highly immunogenic and well-tolerated in Korean adolescents. (Clinical Trial Registry NCT00483470).

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.

[Prevalence of antibodies to hepatitis A virus in healthcare workers and associated variables]. / Prevalencia de anticuerpos frente al virus de la hepatitis A en trabajadores del ámbito sanitario y variables asociadas.

OBJECTIVE: Vaccination against hepatitis A is recommended in risk groups, including healthcare workers. The objective of this study was to determine the prevalence of antibodies to HAV (IgG) among workers in the healthcare setting in order to establish criteria for vaccination. METHODS: A cross-sectional, analytic, observational study of 4,864 employees was undertaken in four healthcare companies in Catalonia (Spain). The variables gathered included personal data, professional category, location of employment, and serology. RESULTS: The overall prevalence of antibodies to HAV was 52.7%. The prevalence significantly increased with greater age. The mean age of seropositive workers was 41.5 years compared with 34.3 in workers with negative serology. The highest prevalence of antibodies was found in cleaning employees (74.2%) and catering staff (75.3%). DISCUSSION: Given the high prevalence of seronegative adults susceptible to infection and the characteristics of their professional activities, vaccination of all staff working in health institutions should be considered.

Declining prevalence of hepatitis A virus antibodies among children from low socioeconomic groups reinforces the need for the implementation of hepatitis A vaccination in Brazil

Age-related seroprevalence studies that have been conducted in Brazil have indicated a transition from a high to a medium endemicity of hepatitis A virus (HAV) infection in the population. However, most of these studies have focused on urban populations that experience lower incidence rates of HAV infection. In the current study, the prevalence of anti-HAV antibodies was investigated in children with a low socioeconomic status (SES) that live on the periphery of three capital cities in Brazil. A total of 1,162 dried blood spot samples were collected from individuals whose ages ranged from one-18 years and tested for anti-HAV antibodies. A large number of children under five years old (74.1-90%) were identified to be susceptible to HAV infection. The anti-HAV antibody prevalence reached ≥ 50% among those that were 10-14 years of age or older. The anti-HAV prevalence rates observed were characteristics of regions with intermediate level of hepatitis A endemicity. These data indicated that a large proportion of children with a low SES that live at the periphery of urban cities might be at risk of contracting an HAV infection. The hepatitis A vaccine that is currently offered in Brazil is only available for high-risk groups or at private clinics and is unaffordable for individuals with a lower SES. The results from this study suggest that the hepatitis A vaccine should be included in the Brazilian National Program for Immunisation.

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.