Eficacia, seguridad y recomendaciones de uso de vacunas contra hepatitis A en niños expuestos e infectados por virus de inmunodeficiencia humana (VIH) / Efficacy, safety and usage recommendations of vaccines against hepatitis A in children exposed and infected by the immunodeficiency virus human (HIV)

ANTECEDENTES: La inmunización de niños infectados o expuestos al VIH representa una estrategia fundamental para reducir la morbilidad y mortalidad por enfermedades infecciosas prevenibles por vacunación, cuyo riesgo es marcadamente elevado en esta población debido al compromiso del sistema inmune. Sin embargo, una menor cantidad de niños con VIH logran inmunidad protectora y aquellos que lo hacen pueden experimentar una disminución mayor y más rápida de la inmunidad. La importancia de prevenir la infección por el virus de la hepatitis A (VHA) en el contexto de la coinfección con VIH radica en que la inmunosupresión asociada al VIH puede incrementar la duración, virulencia y patogenicidad del VHA, a su vez que la infección por VHA puede afectar el curso de la enfermedad por VIH. OBJETIVO: Describir la evidencia científica disponible en relación a la eficacia, seguridad y recomendaciones de uso de vacunas contra hepatitis A en niños expuestos e infectados por virus de inmunodeficiencia humana (VIH). OBJETIVO: Describir la evidencia científica disponible en relación a la eficacia, seguridad y recomendaciones de uso de vacunas contra hepatitis A en niños expuestos e infectados por virus de inmunodeficiencia humana (VIH). MÉTODO: Búsqueda electrónica de estudios publicados en español o inglés en PubMed, Cochrane Library, Web of Science y LILACS hasta el 27 de noviembre de 2021. Adicionalmente, se realizó una búsqueda en PubMed y repositorios de organismos elaboradores de Guías de Práctica Clínica. La selección de estudios fue desarrollada por un solo revisor. RESULTADOS: Se incluyeron diez estudios para la evaluación de la eficacia y seguridad y cuatro documentos para la evaluación de las recomendaciones de uso de vacunas contra hepatitis A en niños expuestos e infectados por virus de inmunodeficiencia humana (VIH). Seroprevalencia contra VHA al inicio del estudio: El porcentaje de participantes con presencia de anticuerpos contra VHA al inicio de estudio fue generalmente bajo (mediana: 12.2%; rango: 2.9% a 48.3%). Inmunogenicidad de las vacunas contra VHA: Tras una primera dosis de inmunización contra el VHA, la seroconversión se produjo en un 68.6% a 87.1% de participantes (mediana: 76.7%). Tras una segunda dosis, el porcentaje de seroconversión se ubicó en el rango de 84.5% a 100% (mediana: 98%). El porcentaje o recuento inicial de CD4 fue un importante predictor de la concentración de anticuerpos. Un único estudio evaluó el efecto de una tercera dosis de vacuna contra el VHA aplicada 18 meses después de la segunda dosis, obteniendo seropositividad de 97%, con un 76% con altos títulos de anticuerpos (≥ 250 mIU/mL). El título medio de anticuerpos fue mayor con tres dosis, comparado con dos dosis de vacuna (602 vs. 287 mUI / ml; p< 0,0001). Eventos adversos asociados a la vacunación: La vacunación contra el VHA en niños infectados o expuestos al VIH produjo eventos adversos leves y en su mayoría autolimitados. La carga viral media de VIH no varió en los niños con VIH vacunados. Duración de la protección después de la inmunización: Se evaluó la presencia de anticuerpos contra el VHA habiendo transcurrido 18 meses después de la aplicación de la segunda dosis de la vacuna. De 120 participantes, 108 (90%) tenían títulos de anticuerpos protectores persistentes, mientras que 12 (10%) no los tenían. Entre quienes no los tenían, dos participantes nunca presentaron respuesta protectora, nueve tuvieron títulos de anticuerpos de ≥ 20 a ≤ 250 mUI/mL tras la segunda dosis, y uno tuvo títulos de anticuerpos de 329 mUI/mL tras la segunda dosis. Los sujetos con bajas respuestas de anticuerpos después de dos dosis de la vacuna contra el VHA tuvieron menor probabilidad de mantener seropositividad 18 meses después que aquellos con altas respuestas de anticuerpos (p= 0.0003). Recomendaciones sobre la vacunación contra VHA en niños con VIH: El NIH de Estados Unidos, y el Ministerio de Salud y Protección Social de Colombia recomiendan dos dosis de vacunas contra VHA en niños con VIH a los 12 y 18 meses. El Ministerio de Salud Pública de Ecuador recomienda solo una dosis a los 12 meses. La Organización Mundial de la Salud recomienda la inmunización contra VHA con un esquema de dos dosis en grupos de riesgo de contraer hepatitis A e inmunodeprimidos. CONCLUSIONES: En los diferentes estudios, la seroprevalencia inicial de anticuerpos contra el virus de la hepatitis A (VHA) fue muy baja, con una mediana de 12.2%, lo cual indica una gran proporción de niños infectados o expuestos a VIH susceptibles a infección por VHA. La aplicación de una primera dosis de vacuna contra VHA produjo una mediana de seroconversión de 76.7%, mientras que una segunda dosis alcanzó una mediana de seroconversión del 98%. El estado inicial de linfocitos T CD4+ fue un importante predictor de la concentración de anticuerpos contra el VHA tras la inmunización. Un mayor recuento o porcentaje inicial de CD4 se asoció con mayor seroconversión, títulos de anticuerpos más altos y mayor probabilidad de mantener seropositividad 18 meses después de la segunda dosis. Resultados de un único estudio muestran que 18 meses después de la aplicación de la segunda dosis de la vacuna contra VHA, un 8.3% de niños dejaron de tener anticuerpos protectores contra el VHA. Resultados de un único estudio muestran que la aplicación de una tercera dosis de vacuna contra VHA 18 meses después de la segunda dosis no alteró el porcentaje personas con seroconversión, pero produjo mayores concentraciones de anticuerpos que quienes solo recibieron dos dosis. La vacunación contra el VHA en niños infectados o expuestos al VIH produjo eventos adversos leves y en su mayoría autolimitados. La carga viral media de VIH no varió en los niños con VIH vacunados. El NIH de Estados Unidos y el Ministerio de Salud y Protección Social de Colombia recomiendan dos dosis de vacunas contra VHA en niños con VIH a los 12 y 18 meses. El Ministerio de Salud Pública de Ecuador recomienda solo una dosis a los 12 meses. La Organización Mundial de la Salud recomienda la inmunización contra VHA con un esquema de dos dosis en grupos de riesgo de contraer hepatitis A e inmunodeprimidos.

Changes to country-specific hepatitis A travel vaccination recommendation for UK travellers in 2017-responding to a vaccine shortage in the national context.

OBJECTIVES: A routine review of hepatitis A travel vaccination recommendations was brought forward in June 2017 due to hepatitis A vaccine shortages and a concurrent outbreak in men who have sex with men (MSM). There were three objectives: first, to document the review process for changing the recommendations for the UK travellers in June 2017. Second, to study the impact of these changes on prescribing in general practice in 2017 compared with the previous 5 years. Third, to study any changes in hepatitis A notifications in June-October 2017 compared with the previous 5 years. STUDY DESIGN: This is an observational study. METHODS: Travel vaccination recommendations for countries with either low-risk (<20%) or high-risk (>90%) status according to child hepatitis A seroprevalence were not changed. A total of 67 intermediate-risk countries with existing recommendations for most travellers and with new data on rural sanitation levels were shortlisted for the analysis. Data on child hepatitis A seroprevalence, country income status, access to sanitation in rural areas and traveller volumes were obtained. Information about the vaccine supply was obtained from Public Health England. Changes to the existing classification were made through expert consensus, based on countries' hepatitis A seroprevalence, sanitation levels, level of income, volume of travel and hepatitis A traveller cases. Data on the number of combined and monovalent hepatitis A-containing vaccines prescribed in England, 2012-2017, were obtained from the National Health Service Business Service Authorities. The number of monthly prescriptions for January-September 2017 was compared with the mean number of prescriptions for the same month in the previous 5 years (t-test, α = 5%, df = 4). The number of hepatitis A cases notified in June-October 2017 not related to the MSM outbreak was compared with the number of notifications in the same months in previous years. RESULTS: A total of 36 countries were downgraded based on good access (80+% of population) to sanitation in rural areas and the intermediate-risk status in terms of child hepatitis A seroprevalence. For these countries, vaccination would only be recommended to travellers staying long term, visiting friends and relatives or staying in areas without good sanitation. There was a significant decline in hepatitis A vaccine prescriptions in June-September 2017, and there was no increase in the number of notifications. CONCLUSIONS: Hepatitis A vaccination recommendations for travel were revised in 2017 following a systematic approach to maintain continuity of supply after a hepatitis A vaccine shortage and increased hepatitis A vaccine demand related to a large outbreak. Improved access to good sanitation in rural areas and low seroprevalence estimates among children have led to 36 countries to no longer require vaccination for most travellers. These changes do not seem to have impacted on hepatitis A notifications in England, although further research will be needed to quantify the impact more precisely.

Update From the Advisory Committee on Immunization Practices.

The Advisory Committee on Immunization Practices (ACIP), a group of medical and public health experts, meets 3 times per year to develop recommendations for vaccine use in the United States. There are 15 voting members, and their terms are for 4 years. ACIP members and Centers for Disease Control and Prevention staff discuss the epidemiology of vaccine-preventable diseases and vaccine research, effectiveness, safety data, and clinical trial results. Representatives from the American Academy of Pediatrics (including D. W. K.) and the Pediatric Infectious Diseases Society are present as liaisons to the ACIP. In the February 2018 meeting, important votes on the use of influenza vaccine and hepatitis vaccines were held, and updates on human papillomavirus, meningococcal, and anthrax vaccines, among others, were provided.

[Analysis on coverage of hepatitis A vaccine among pre-school children in Shandong province].

OBJECTIVE: To reveal the hepatitis A vaccine (HepA) coverage among pre-school children in Shandong province before Hepatitis A vaccine was introduced to the EPI and to provide evidence for improving the strategy for hepatitis A control. METHODS: A cross-section survey was conducted among children aged between 2 and 6 years old in Shandong province in March 2008. The study population was selected by random sampling method and HepA immunization history was obtained by immunization record or recall. RESULTS: 78.90% had received one dose of HepA at least. The coverage rate decreased with age and the differences in three age groups were statistically significant (chi2 = 11.54, P = 0.02). The coverage rates among the boys and girls were 77.67% and 80.30% respectively, the difference was not significantly (chi2 = 1.17, P = 0.28). The HepA coverage rates among the children living in the eastern areas and in the richer areas were higher than the centrale and western areas and poverty areas, the difference has statistic significance (chi2 = 27.25, 58.17, P < 0.001). CONCLUSION: The HepA routine immunization should be enhanced, especially in central and western areas and a HepA catch-up campaign should be conducted among the pre-school children in Shandong province.

Hepatitis A: disease burden and current childhood vaccination strategies in the United States.

Hepatitis A can be a serious disease and represents a substantial health and economic burden. In recent years, a decline in the number of cases of hepatitis A has been observed, which has been attributed in part to the implementation of vaccination policies in states with high disease incidence. In May 2006, the Advisory Committee on Immunization Practices published updated recommendations to include routine hepatitis A vaccination for all children beginning at 12 to 23 months of age. In this review, information on hepatitis A disease burden is presented with a discussion on the new recommendations and implementation of hepatitis A vaccination.

Geographic analysis of vaccine uptake in a cluster-randomized controlled trial in Hue, Vietnam.

This paper identifies spatial patterns and predictors of vaccine uptake in a cluster-randomized controlled trial in Hue, Vietnam. Data for this study result from the integration of demographic surveillance, vaccine record, and geographic data of the study area. A multi-level cross-classified (non-hierarchical) model was used for analyzing the non-nested nature of individual's ecological data. Vaccine uptake was unevenly distributed in space and there was spatial variability among predictors of vaccine uptake. Vaccine uptake was higher among students with younger, male, or not literate family heads. Students from households with higher per-capita income were less likely to participate in the trial. Residency south of the river or further from a hospital/polyclinic was associated with higher vaccine uptake. Younger students were more likely to be vaccinated than older students in high- or low-risk areas, but not in the entire study area. The findings are important for the management of vaccine campaigns during a trial and for interpretation of disease patterns during vaccine-efficacy evaluation.

Hepatitis A in the era of vaccination.

The World Health Organization estimates an annual total of 1.5 million clinical cases of hepatitis A worldwide, but seroprevalence data indicate that tens of millions of hepatitis A virus infections occur each year. In the United States in the 1980s-1990s, an average of 26,000 acute hepatitis A cases were reported per year, representing approximately 270,000 infections annually. Since licensure of effective hepatitis A vaccines in the mid-1990s, US hepatitis A rates have fallen precipitously-particularly since 1999, when routine childhood vaccination was recommended in states with consistently elevated rates. By 2004, the overall rate had declined to 1.9/100,000 population, the lowest rate ever recorded and 79% lower than any previously recorded nadir. These marked declines occurred with relatively modest vaccination coverage, suggesting that strong herd immunity accompanies the initiation of routine vaccination programs. Routine childhood vaccination has produced similar results in Israel and selected regions of Italy, Spain, and Australia. Hepatitis A vaccination will probably remain a low priority for some time in the poorest countries, where most persons are infected as young children. However, shifts in the epidemiologic patterns of disease associated with declining hepatitis A virus transmission are occurring in many regions of the world. These shifts are likely to create circumstances where strategically targeted vaccination of children could produce substantial public health benefits.

Hepatitis A and B vaccination in a sexually transmitted disease clinic for men who have sex with men.

BACKGROUND: Sexually transmitted disease clinics can deliver hepatitis vaccines to men who have sex with men, but have been reluctant to do so because of perceived low vaccination completion rates. GOAL: The goal was to evaluate hepatitis A and B vaccination eligibility, acceptance, and completion and the effectiveness of reminder/recall in a sexually transmitted disease clinic serving men who have sex with men. DESIGN: Clients self-reported their eligibility for free vaccine. Consenting clients who accepted a first dose of vaccine were systematically assigned to receive telephone reminder/recall or standard follow-up. RESULTS: Of 1203 clients, 71.8% were eligible for both vaccines; 62.6% of those eligible accepted both. Reminder/recall was associated with increased receipt of the second dose of hepatitis B vaccine (86.7% versus 80.4% among intervention and control groups, respectively), but not with completion of both vaccine series (55.9% versus 58.8%). CONCLUSION: The majority of clients were eligible for both hepatitis vaccines, and most eligible clients accepted a first dose of both vaccines. Reminder/recall, as delivered at this clinic, failed to increase the proportion of clients who received all vaccine doses. New delivery mechanisms should be explored.

Hepatitis A vaccination during an outbreak among gay men in Montréal, Canada, 1995-1997.

STUDY OBJECTIVE: To evaluate an intervention designed to curtail an outbreak of hepatitis A among gay men, especially the young and sexually active, by promoting their free vaccination. DESIGN: The study analysed routine passive surveillance data, carried out questionnaire and serological surveys of vaccinees, and surveys among the target population in non-clinical venues. SETTING AND INTERVENTION: 15 000 free doses of hepatitis A vaccine were made available through clinics with large gay clienteles, or at gay events, and advertised by various means, in Montréal, Canada, from August 1996 to November 1997. Simultaneous vaccination against hepatitis B (always free for gay men) was also encouraged. PARTICIPANTS: Information was obtained from persons with the disease during the epidemic period, a sample of men requesting vaccination, and five community samples of gay men. MAIN RESULTS: The outbreak involved 376 gay men and the vaccine was distributed to approximately 10 000. Vaccinees were older than cases, but had many sex partners and comprised more food handlers. Special vaccination clinics at gay events were well attended but did not reach more high risk men than regular medical venues. A self reported vaccine coverage of 49% was achieved, but 26% of vaccinees already had anti-HAV antibodies. Disease incidence declined rapidly during the campaign. CONCLUSIONS: The intervention nearly tripled self reported hepatitis A vaccine coverage but its late start precludes proving that it caused the subsequent drop in incidence. However, it also increased hepatitis B vaccination and it is believed it improved links between gay men, public health, clinicians and community groups.