RESUMO
BACKGROUND: Current hepatitis A vaccines are either licensed for children >2 years of age, as in the U.S. or Chile, or >1 year of age, as in Europe and other parts of the world. Recent recommendations for immunization against hepatitis A have included routine vaccination of children in areas or regions of higher endemicity. However, data on hepatitis A vaccination in toddlers aged between 1 and 2 years are scarce. METHODS: This open clinical study investigated the reactogenicity and immunogenicity of two doses (0, 6-month schedule) of an inactivated hepatitis A vaccine (Havrix pediatric, Glaxco SmithKline Biologicals, Rixensart, Belgium) in 120 seronegative children aged 12-24 months. RESULTS: Pain at the injection site and irritability were the most frequently reported local and general symptoms, respectively. No serious adverse events related to the study vaccine were reported. One month after the first dose, all but one subject had antibodies against hepatitis A with a GMT of 159 mIU/mL. After the booster dose, all had antibodies with a GMT of 2,939 mIU/mL. CONCLUSIONS: Our data show that the inactivated hepatitis A vaccine was well tolerated by these toddlers and that the vaccine elicits a good immune response.
Assuntos
Vacinas contra Hepatite A/imunologia , Hepatite A/prevenção & controle , Anticorpos Anti-Hepatite/biossíntese , Pré-Escolar , Eritema/etiologia , Feminino , Febre/etiologia , Anticorpos Anti-Hepatite A , Vacinas contra Hepatite A/efeitos adversos , Anticorpos Anti-Hepatite/sangue , Humanos , Imunização Secundária , Lactente , Masculino , Dor/etiologia , Vacinas de Produtos Inativados/efeitos adversos , Vacinas de Produtos Inativados/imunologiaRESUMO
A doença causada pelo virus da hepatite A (VHA) costuma ser considerada como benigna, afetando principalmente os pré-escolares. Contudo, nesta revisäo se discutem os vários grupos da populaçäo em geral, nos quais a infecçäo pelo VHA pode apresentar consequências mais graves. Em consequência da alteraçäo epidemiológica verificada na América Latina, um número cada vez maior de adolescentes e adultos jovens se mantêm suscetíveis à infecçäo pelo VHA. A infecçäo por esse vírus, neste grupo etário, irá representar grave impacto no futuro, ausência prolongada ao trabalho e/ou escola e custos maiores para os sistemas locais de saúde. Em estudos recentes na Argentina e Chile, o VHA foi, também, o agente etiológico mais prevalente nos casos de insuficiência hepática fulminante em pré-escolares. A hepatite A aguda em pacientes com doença hepática crônica subjacente, especialmente hepatite C crônica, tem sido associada à insuficiência hepática grave ou fulminante. A prevençäo da hepatite A através da vacinaçäo parece ser o meio mais potente de se conter o VHA. As vacinas inativadas contra a hepatite A comprovaram ser seguras, altamente imunogênicas e indutoras de proteçäo duradoura contra infecçöes pelo VHA
Assuntos
Humanos , Pré-Escolar , Criança , Adolescente , Adulto , Vacinas contra Hepatite Viral , Hepatovirus , Hepatite A/complicações , Hepatite A/prevenção & controle , Hepatite A/epidemiologia , Surtos de Doenças/prevenção & controleRESUMO
BACKGROUND: As sanitary conditions of a population improve, hepatitis A virus infection occurs at higher ages, thus decreasing the prevalence of antibodies against the virus. In the eighties, the prevalence of antibodies among children was 97% and depended on the socioeconomic level. AIM: To assess the prevalence of antibodies against hepatitis A virus in school age children living in Valdivia. SUBJECTS AND METHODS: Two thousand three hundred thirty three school age children were studied. Total antibodies against hepatitis A virus were detected using an ELISA kit from Abbott. Children were stratified in age groups and school were classified as private, subsidized, municipal or foster homes. RESULTS: Antibodies were positive in 65% of children (59% in children aged 6 to 8 years old, 66% in children aged 9 to 11 years and 69% in children aged 12 to 15 years. In private schools, the prevalence was 26%, in subsidized schools the figure was 54%, in municipal schools 73% and in foster homes 91%. CONCLUSIONS: The general prevalence of antibodies against hepatitis A virus is higher in low socioeconomic level children. There is a global decrease in the prevalence of these antibodies in the last years.
Assuntos
Hepatite A/epidemiologia , Anticorpos Anti-Hepatite/sangue , Adolescente , Criança , Chile/epidemiologia , Feminino , Hepatite A/sangue , Hepatovirus/imunologia , Humanos , Masculino , Prevalência , Estudos Soroepidemiológicos , Fatores SocioeconômicosRESUMO
Background: Children are of an age group susceptible to infection by the hepatitis A virus (HAV). Active immunization of children against HAV became reality in 1993, when the first pediatric hepatitis A vaccine was licensed. This initial vaccine required two injections to induce a full immune response in recipients. The purpose of this study was to assess the feasibility of a single dose primary vaccine plus a booster after 6 months against hepatitis A in children. Methods: A total of 60 healthy and seronegative children between 2 and 13 years of age were administered inactivated hepatitis A vaccine, containing 720 enzyme-linked immunosorbent assay (ELISA) units (EL.U) of hepatitis A antigen, intramuscularly in the deltoid region at months 0 and 6. Symptoms were recorded by parents or guardians on individual diary cards. Antibodies against HAV (antiHAV) were measured using an ELISA inhibition assay, and a seropositive titer was defined as being >=20 mIU/mL. Results: Fifteen days after the single primary dose, 96% of the vaccinees were seropositive with a geometric mean titer (GMT) of 351 mIU/mL. The seropositivity rate reached 100% 1 month after the first dose, with a GMT of 305 mIU/mL. Prior to the second dose at month 6, 93% remained seropositive, and the GMT was 153 mIU/mL. By month 7, 1 month after the second vaccination, the seropositivity rate recovered to 100% with a rise in GMTs to 3644 mIU/mL. Local symptoms were reported after 23.9% of doses, and general symptoms after 19.7% of doses. All symptoms were of short duration and resolved spontaneously. Conclusions: This inactivated vaccine against hepatitis A is safe, well-tolerated, and excellently immunogenic when administered to children following a single dose plus booster course at months 0 and 6.
RESUMO
UNLABELLED: In large areas of the Amazon jungle from Brazil, Colombia, Venezuela and Peru, it has been reported hyperendemic HBV and delta focus. In the Peruvian jungle we found up to 97% of prevalence of HBV, on the northern Jívaro tribes vs the southern tribes, Arawak, (65%). In this paper we studied 226 volunteers from 6 Jívaro and 3 Arawak villages, who accepted to be vaccinated with a DNA recombinant vaccine (ENGERIX B); all of them were previously HBsAg/Ab negatives but 55.5% of them were anti-core (IgG) positive. Our results show 84.9% of seroconversion to anti-HBs, and 73.5% was consider to be immunized (> 10 mIU/ml). Better response was observed in those that were HBcAb negative, coming from a low endemic area. We also observed a good vaccine response although we had to change months the response decreased up to 51.8% of seroimmunity. Higher anti-HBs titles was observed in the southern tribes: MGC of 416.3 mIU/ml. compared with the south: MGC: 182.2 mIU/ml. CONCLUSIONS: It is important to check previously, in hyperendemic areas, HBV markers, specially. It is important to receive the second dose between with the third dose up to 14 month. The immune response overall was good: the ABsAb titles obtained was in average, 290 mIU/ml (10.2-41,00). Apparently the vaccine do not suffer during the difficulties in transportation in the jungle. No side effects we shown during the vaccination program.