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BackgroundTo combat the hesitancy towards implementing a hepatitis A universal mass vaccination (UMV) strategy and to provide healthcare authorities with a comprehensive analysis of the potential outcomes and benefits of the implementation of such a vaccination program, we projected HAV seroprevalence and incidence rates in the total population of the Russian Federation and estimated the pediatric vaccination threshold required to achieve an incidence level of less than 1 case per 100,000 using a new mathematical model.MethodsA dynamic age-structured SEIRV (susceptible-exposed-infectious-recovered-vaccinated) compartmental model was developed and calibrated using demographic, seroprevalence, vaccination, and epidemiological data from different regions of the Russian Federation. This model was used to project various epidemiological measures.ResultsThe projected national average age at the midpoint of population immunity increases from 40 years old in 2020 to 50 years old in 2036 and is shifted even further to the age of 70 years in some regions of the country. An increase of varying magnitude in the incidence of symptomatic HAV infections is predicted for all study regions and for the Russian Federation as a whole between 2028 and 2032, if the HAV vaccination coverage level remains at the level of 2022. The national average vaccination coverage level required to achieve a symptomatic HAV incidence rate below 1 case per 100,000 by 2032 was calculated to be 69.8% if children aged 1–6 years are vaccinated following the implementation of a UMV program or 34.8% if immunization is expanded to children aged 1–17 years.ConclusionThe developed model provides insights into a further decline of herd immunity to HAV against the background of ongoing viral transmission. The current favorable situation regarding hepatitis A morbidity is projected to be replaced by an increase in incidence rates if vaccination coverage remains at the current levels. The obtained results support the introduction of a hepatitis A UMV strategy in the Russian Federation.

The data on hepatitis A virus (HAV) seroprevalence are critical for the implementation of a universal mass vaccination (UMV) strategy. The latter has not been implemented in Russia; however, regional child vaccination programs have been adopted in some parts of the country. The aim of this study is to assess changes in HAV immunity within the last decade in regions of Russia with different vaccination strategies and different vaccination coverage rates. In regions where UMV has not been implemented and HAV vaccination coverage rates do not exceed the national average, the 50% seroprevalence threshold has shifted in the Moscow region from people aged under 40 years in 2008 to people aged over 59 years in 2020, and from people aged under 30 years to people aged over 40 years in the Khabarovsk region. In two regions (Yakutia and Sverdlovsk), a two-dose-based UMV scheme has been in place since 2011 and 2003, respectively, and in Tuva single-dose child immunization was launched in 2012. These regional programs have resulted in a significant increase in HAV seroprevalence in children and adolescents. In Yakutia, 50% herd immunity had been achieved by 2020 in age groups under 20 years, compared to 20–30% seroprevalence rates in 2008. In the Sverdlovsk region, HAV immunity has increased to >65% over the decade in children aged over 10 years, adolescents and young adults, whereas it declined in older age groups. However, a three-fold drop in HAV immunity has occurred in children under 10 years of age, reflecting a significant decline in vaccination coverage. In Tuva, HAV immunity rates in children under 10 years old increased two-fold to exceed 50% by 2020. These data suggest that UMV should be implemented on a national level. Measures to control vaccination coverage and catch-up vaccination campaigns are recommended in order to maintain the effectiveness of existing HAV vaccination programs. [ABSTRACT FROM AUTHOR]

Hepatitis A virus (HAV) infection is a notifiable disease in Ireland, with national coverage of clinical and laboratory surveillance. In December 2020, a cluster of 11 HAV cases among the Irish Traveller community was detected. The outbreak investigation identified 61 total HAV cases from September 2020 to November 2021. Sequenced isolates were sub-genotype IA with identical genome sequence. Case-patients were predominantly aged under 18 (77%), hospitalised (46%) and lived on communal residential sites. Mass onsite HAV vaccination was employed following failure of initial ring vaccination to contain the outbreak. This is the largest outbreak of HAV described in Ireland, involving spillover to the UK and Netherlands. We recommend mass HAV vaccination and tailored communication for outbreak control in migratory subpopulations. [ABSTRACT FROM AUTHOR]

Acute hepatitis A viral (HAV) infection is rare in the liver transplant population due to recommended pre-transplant vaccinations. We report a case of acute hepatitis A infection in a liver transplant recipient. This individual had immunity to hepatitis A with protective IgG antibodies and presented with abnormal liver biochemistry in the post-transplant in-patient setting. Hepatitis A infection was confirmed by positive HAV IgM whereas other etiologies, including acute cellular rejection, were ruled out by laboratory tests and liver biopsies. He was treated conservatively with supportive care and liver enzymes recovered to normal baseline. Despite adequate pre-transplant immunity, in the post-transplant setting there may be loss of protective immunity due to profound immunosuppression and hence hepatitis A should remain an important differential diagnosis in the setting of acute hepatitis.

The data on hepatitis A virus (HAV) seroprevalence are critical for the implementation of a universal mass vaccination (UMV) strategy. The latter has not been implemented in Russia; however, regional child vaccination programs have been adopted in some parts of the country. The aim of this study is to assess changes in HAV immunity within the last decade in regions of Russia with different vaccination strategies and different vaccination coverage rates. In regions where UMV has not been implemented and HAV vaccination coverage rates do not exceed the national average, the 50% seroprevalence threshold has shifted in the Moscow region from people aged under 40 years in 2008 to people aged over 59 years in 2020, and from people aged under 30 years to people aged over 40 years in the Khabarovsk region. In two regions (Yakutia and Sverdlovsk), a two-dose-based UMV scheme has been in place since 2011 and 2003, respectively, and in Tuva single-dose child immunization was launched in 2012. These regional programs have resulted in a significant increase in HAV seroprevalence in children and adolescents. In Yakutia, 50% herd immunity had been achieved by 2020 in age groups under 20 years, compared to 20–30% seroprevalence rates in 2008. In the Sverdlovsk region, HAV immunity has increased to >65% over the decade in children aged over 10 years, adolescents and young adults, whereas it declined in older age groups. However, a three-fold drop in HAV immunity has occurred in children under 10 years of age, reflecting a significant decline in vaccination coverage. In Tuva, HAV immunity rates in children under 10 years old increased two-fold to exceed 50% by 2020. These data suggest that UMV should be implemented on a national level. Measures to control vaccination coverage and catch-up vaccination campaigns are recommended in order to maintain the effectiveness of existing HAV vaccination programs.

Background: To combat the hesitancy towards implementing a hepatitis A universal mass vaccination (UMV) strategy and to provide healthcare authorities with a comprehensive analysis of the potential outcomes and benefits of the implementation of such a vaccination program, we projected HAV seroprevalence and incidence rates in the total population of the Russian Federation and estimated the pediatric vaccination threshold required to achieve an incidence level of less than 1 case per 100,000 using a new mathematical model., Methods: A dynamic age-structured SEIRV (susceptible-exposed-infectious-recovered-vaccinated) compartmental model was developed and calibrated using demographic, seroprevalence, vaccination, and epidemiological data from different regions of the Russian Federation. This model was used to project various epidemiological measures., Results: The projected national average age at the midpoint of population immunity increases from 40 years old in 2020 to 50 years old in 2036 and is shifted even further to the age of 70 years in some regions of the country. An increase of varying magnitude in the incidence of symptomatic HAV infections is predicted for all study regions and for the Russian Federation as a whole between 2028 and 2032, if the HAV vaccination coverage level remains at the level of 2022. The national average vaccination coverage level required to achieve a symptomatic HAV incidence rate below 1 case per 100,000 by 2032 was calculated to be 69.8% if children aged 1-6 years are vaccinated following the implementation of a UMV program or 34.8% if immunization is expanded to children aged 1-17 years., Conclusion: The developed model provides insights into a further decline of herd immunity to HAV against the background of ongoing viral transmission. The current favorable situation regarding hepatitis A morbidity is projected to be replaced by an increase in incidence rates if vaccination coverage remains at the current levels. The obtained results support the introduction of a hepatitis A UMV strategy in the Russian Federation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Taratorkin, Karlsen, Kyuregyan, Lopatukhina, Khankishiyev, Manuylov, Akimkin and Mikhailov.)

Hepatitis A and B disease burden persists in the US. We assessed hepatitis A and hepatitis B vaccination series completion rates among 350,240 commercial/Medicare and 12,599 Medicaid enrollees aged ≥19 years. A vaccination series was considered as completed provided that the minimum interval between doses, as defined by the CDC, and the minimum number of doses were reached. We stratified completion rates by vaccine type (i.e. monovalent or bivalent) at initial vaccination for each cohort. In the commercial/Medicare cohort, the series completion rate was 32.0% for hepatitis A and 39.6% for hepatitis B among those who initiated with a monovalent vaccine, and it was 36.2% for hepatitis A and 48.9% for hepatitis B among those who initiated with a bivalent vaccine. In the Medicaid cohort, the series completion rate was 21.0% for hepatitis A and 24.0% for hepatitis B among those who initiated with a monovalent vaccine, and it was 19.0% for hepatitis A and 24.6% for hepatitis B among those who initiated with a bivalent vaccine. In conclusion, hepatitis A and B vaccination series completion rates were low, and appeared to be lower among Medicaid than among commercial/Medicare enrollees. Commercial/Medicare enrollees who initiated with a bivalent vaccine had higher series completion rates than those who initiated with monovalent vaccines – an observation that was not made among Medicaid enrollees.

Acute hepatitis A viral (HAV) infection is rare in the liver transplant population due to recommended pre-transplant vaccinations. We report a case of acute hepatitis A infection in a liver transplant recipient. This individual had immunity to hepatitis A with protective IgG antibodies and presented with abnormal liver biochemistry in the post-transplant in-patient setting. Hepatitis A infection was confirmed by positive HAV IgM whereas other etiologies, including acute cellular rejection, were ruled out by laboratory tests and liver biopsies. He was treated conservatively with supportive care and liver enzymes recovered to normal baseline. Despite adequate pre-transplant immunity, in the post-transplant setting there may be loss of protective immunity due to profound immunosuppression and hence hepatitis A should remain an important differential diagnosis in the setting of acute hepatitis. [ABSTRACT FROM AUTHOR]

Background: Hepatitis A outbreaks in the United Kingdom are uncommon. Most people develop mild to moderate symptoms that resolve, without sequelae, within months. However, in high-risk groups, including those with underlying chronic liver disease (CLD), hepatitis A infection can be severe, with a higher risk of mortality and morbidity. The Health Security Agency and the National Institute of Health and Care Excellence recommend preexposure hepatitis A vaccination given in 2 doses to people with CLD, regardless of its cause. There are currently no published reports of vaccination coverage for people with CLD in England or internationally., Objective: This study aims to describe hepatitis A vaccination coverage in adults with CLD in a UK primary care setting and compare liver disease etiology, sociodemographic characteristics, and comorbidities in people who are and are not exposed to the hepatitis A vaccine., Methods: We will conduct a retrospective cohort study with data from the Primary Care Sentinel Cohort of the Oxford-Royal College of General Practitioners Clinical Informatics Digital Hub database, which is nationally representative of the English population. We will include people aged 18 years and older who have been registered in general practices in the Research and Surveillance Centre network and have a record of CLD between January 1, 2012, and December 31, 2022, including those with alcohol-related liver disease, chronic hepatitis B, chronic hepatitis C, nonalcohol fatty liver disease, Wilson disease, hemochromatosis, and autoimmune hepatitis. We will carefully curate variables using the Systematized Nomenclature of Medicine Clinical Terms. We will report the sociodemographic characteristics of those who are vaccinated. These include age, gender, ethnicity, population density, region, socioeconomic status (measured using the index of multiple deprivation), obesity, alcohol consumption, and smoking. Hepatitis A vaccination coverage for 1 and 2 doses will be calculated using an estimate of the CLD population as the denominator. We will analyze the baseline characteristics using descriptive statistics, including measures of dispersion. Pairwise comparisons of case-mix characteristics, comorbidities, and complications will be reported according to vaccination status. A multistate survival model will be fitted to estimate the transition probabilities among four states: (1) diagnosed with CLD, (2) first dose of hepatitis A vaccination, (3) second dose of hepatitis A vaccination, and (4) death. This will identify any potential disparities in how people with CLD get vaccinated., Results: The Research and Surveillance Centre population comprises over 8 million people. The reported incidence of CLD is 20.7 cases per 100,000. International estimates of hepatitis A vaccine coverage vary between 10% and 50% in this group., Conclusions: This study will describe the uptake of the hepatitis A vaccine in people with CLD and report any disparities or differences in the characteristics of the vaccinated population., International Registered Report Identifier (irrid): PRR1-10.2196/51861., (©Bernardo Meza-Torres, Anna Forbes, William Elson, Debasish Kar, Gavin Jamie, William Hinton, Xuejuan Fan, Rachel Byford, Michael Feher, Martin Whyte, Mark Joy, Simon de Lusignan. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 24.10.2023.)

Background. Hepatitis A vaccines are highly immunogenic in healthy patients, but there is uncertainty about their immunogenicity in immunocompromised patients. Methods. Our study included immunocompromised patients who received 1 or 2 hepatitis A vaccinations between January 2011 and June 2013. We assessed factors that influenced the serologic response to vaccination. We performed a literature review of previous studies on hepatitis A vaccination in immunocompromised patients. Results. Of 85 immunocompromised patients, 65 used immunosuppressive drugs, 13 had received stem cell transplants, and 7 were infected with human immunodeficiency virus. After vaccination, 65 of 85 (76.5%) developed antibodies. Tumor necrosis factor α blocker use was associated with better serologic responses than other immunosuppressive drugs. Female patients were more compliant than male patients with postvaccination antibody titer measurements. In 11 relevant studies, antibody responses after the first and second vaccination averaged 37% and 82%, respectively. Factors that negatively influenced serologic response rates were high doses of immunosuppressive drugs, fewer hepatitis A vaccinations, and a short interval between vaccination and antibody measurement. Conclusions. Immunocompromised patients showed moderate to good serologic responses to hepatitis A vaccination, but may need more time to develop immunity. Tumor necrosis factor α blocker use was associated with better antibody responses than other drugs. Specifically, male patients should be motivated to return for antibody titer measurements. [ABSTRACT FROM AUTHOR]

Introduction Routine immunization against hepatitis A virus (HAV) infection has not been warranted in India, but an epidemiological shift from hyperendemicity to intermediate endemicity has been detected in recent years. The present study was planned to gather the age group-specific seroprevalence data of hepatitis A IgG antibodies in various age groups and evaluate any early trends of seroepidemiological shift. Method This was a hospital-based cross-sectional study. The detection of IgG antibodies for hepatitis A was done using an HAV Ab kit (Dia.Pro, Milan, Italy) in sera of individuals from >1 to 80 years of age and consenting to participate. Data on sociodemographic factors and potentially predisposing factors of HAV was collected on a predesigned questionnaire. At the time of final analysis, patients were divided into three groups children one to <18 years, adults ≥18 to <60 years, and old ≥60 to 80 years for comparative analysis. Result A total of 1,250 patients were included in the final analysis (129 children, 928 adults, and 193 old). The male/female ratio of the study participants was 1.4:1. The majority (85%) of them came from rural and semi-urban areas. They generally had lower socioeconomic status (SES) with poor literacy rates. Most of the enrolled cases (n=800/1,250, 64%) reported the use of groundwater, and 58.7% (n=734/1,250) consume water without any purification. Of the study participants, 90.8% reported the use of toilets for defecation, and 96.7% of the cases use soap for handwashing after defecation. The majority of adult (90%) and old age (99%) participants were seropositive for anti-HAV IgG antibodies as compared to children (80%). No significant differences were observed in the seropositivity rates and the SES class of the study participants. Conclusion About 20% of children did not have anti-HAV IgG antibodies in the present study, indicating that they are not exposed to HAV. This could be because of their better living conditions such as the availability of safe drinking water and improved sanitation and hygiene. We support the current guidelines of the Indian Academy of Pediatrics (IAP), which recommends immunization for hepatitis A vaccination at 12 months of age. Adult vaccination is not needed in North India., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Agarwal et al.)

Highlights: [•] HAV immune response after vaccination remains impaired in HIV-infected patients. [•] We analysed the response and associated factors in 282 HIV-infected patients. [•] Response rate of 73.4%, associated with a higher CD4/CD8 ratio. [•] Male sex and hepatitis C virus co-infection associated with a lower response. [•] Sub-optimal effectiveness of three doses of 720 Elisa Units in the rapidly accelerated schedule. [Copyright &y& Elsevier]

The article discusses a study on the seroprevalence of hepatitis A virus (HAV) infection among human immunodeficiency virus (HIV)-negative men who have sex with men (MSM) in the U.S. The study used data from the Young Men's Survey (YMS), a cross-sectional study of HIV prevalence among MSM aged 15 to 29 from 1994 to 2000. Serum samples from HIV-negative MSM were tested for antibodies to HAV (anti-HAV) retrospectively. Overall anti-HAV prevalence was found to vary by ethnicity with Hispanic and Asian men showing the highest prevalence. The authors note the need for more hepatitis A vaccination research to determine the adequacy of vaccination strategies for MSM.

Abstract: Background: Autoimmune mechanisms and drugs used in treatment increase the risk of liver disease in patients with juvenile idiopathic arthritis (JIA) and hepatitis A virus (HAV) vaccination is important, especially in intermediate-endemicity areas like Turkey. In our study, we aimed to evaluate the immune response to hepatitis A vaccine and vaccine safety in children with JIA. Methods: This study was carried out in our hospital’s Pediatric Rheumatology outpatient clinic and Healthy Child clinic between the years 2003 and 2008. The study group consisted of 47 children with JIA (23 male and 24 female) diagnosed according to International League of Associations for Rheumatology diagnostic criteria. The control group consisted of 67 healthy children (31 female, 36 male) who did not have a history of hepatitis A infection or vaccination. Both groups were vaccinated with two doses of hepatitis A vaccine at 6-month intervals. Anti-HAV IgG >80 MIU was accepted as positive response. Results: There was no significant difference between the groups in terms of age and sex. None of the patients with JIA had fever, clinical worsening, or disease activation after vaccination. Anti-HAV IgG positivity rate was significantly higher in the control group (p < 0.05). Anti-HAV IgG was negative in only four cases, and they were all male patients with systemic JIA who had active disease under anti-tumor necrosis factor treatment. Conclusion: Hepatitis A vaccine was safe in patients with JIA, and response to vaccine did not differ between healthy children and patients with JIA except for children with active systemic JIA receiving anti-tumor necrosis factor alpha drugs. [Copyright &y& Elsevier]

Abstract: We analysed data from the 2009 National Immunization Survey to determine potential predictors of hepatitis A vaccination coverage among children aged 19–35 months. Overall national coverage was 75% for ≥1 dose. Residence in a state with hepatitis A vaccination recommendations prior to 2006, or in a metropolitan statistical area within such state, or being a minority child were among the variables independently associated with higher vaccination coverage. While hepatitis A vaccination coverage has improved since nationwide routine childhood vaccination began in 2006, coverage remains lower than that for other recommended childhood vaccines. [Copyright &y& Elsevier]

For the first time a global meeting on hepatitis A virus (HAV) infection as vaccine preventable disease was organized at the end of 2007. More than 200 experts from 46 countries gathered to investigate the changing global HAV epidemiology reflecting the increasing numbers of persons at risk for severe clinical disease and mortality from HAV infection. The benefits of childhood and adult hepatitis A (HepA) vaccination strategies and the data needed by individual countries and international health organizations to assess current HepA prevention strategies were discussed. New approaches in preventing HAV infection including universal HepA vaccination were considered. This introductory paper summarizes the major findings of the meeting and describes the changing epidemiology of HAV infections and the impact of HepA vaccination strategies in various countries. Implementation of HepA vaccination strategies should take into account the level of endemicity, the level of the socio-economic development and sanitation, and the risk of outbreaks. A stepwise strategy for introduction of HepA universal immunisation of children was recommended. This strategy should be based on accurate surveillance of cases and qualitative documentation of outbreaks and their control, secure political support on the basis of high-quality results, and comprehensive cost-effectiveness studies. The recognition of the need for increased global attention towards HepA prevention is an important outcome of this meeting. [ABSTRACT FROM AUTHOR]

Universal hepatitis A (HA) vaccination was implemented by the Argentinean Ministry of Health in June 2005 with a single dose at age 12 months. The decision was made taking into account the following factors. (1) Disease burden: The incidence rate for the disease increased from 2003 to 2004; the northern and western regions of the country were the most affected. Sero-prevalence data for children 1–15 years old was 54% for the whole country, with differences per region and age. From May 1982 to September 2002, 210 patients were recruited with acute hepatic failure; HA was the aetiology in 61% of them. (2) Cost-effectiveness: Compared with no vaccination, the one-dose schedule would save US$15.3 millions, with regional variations. (3) Vaccine features: Immunization with one-dose schedule HA vaccine confers good immunogenicity and effectiveness. (4) Programmatic feasibility: The National Immunizations Program has appropriate distribution system for vaccines, with adequate cold chain. (5) Social acceptance and political compromise: The population largely accepts HA vaccination and the national authorities should be committed to providing it regularly. The main global issue is that hepatitis A virus infection remains the most commonly reported vaccine-preventable disease in many parts of the world despite the availability of vaccines. [ABSTRACT FROM AUTHOR]

Abstract: The present study examined the association between psychological stress, social support and antibody response to both thymus-dependent and thymus-independent vaccinations. Stressful life events in the previous year and customary social support were measured by standard questionnaires at baseline in 75 (41 females) healthy students. Antibody status was assessed at baseline, 4 and 18 weeks following vaccination with formaldehyde inactivated hepatitis A virus and pneumococcal polysaccharides, which induce thymus-dependent and -independent antibody responses respectively. Controlling for baseline antibody status, life event stress was negatively associated with antibody response to the hepatitis A vaccine at the 18-week follow-up; participants reporting a greater number of stressful life events had a poorer antibody response. There was no relationship between psychological stress and antibody response to pneumococcal vaccination. Social support was not associated with the antibody response to hepatitis A vaccination. However, there was a significant association between support and the antibody response to the thymus-independent pneumococcal vaccine at 4-week follow-up; participants with larger social networks mounted a better response. These relationships could not be accounted for by age and sex, or by variations in health behaviours. Psychosocial factors would appear to influence the response to both thymus-dependent and thymus-independent vaccines, but not in the same manner. [Copyright &y& Elsevier]

The use of illegal drugs is associated with an increase in infective risk for the hepatitis viruses, against which the vaccination of drug users (DUs) is recommended unanimously. The aim of the study was to determine tolerability, adherence and immune response of a combined vaccine providing dual protection against hepatitis A virus (HAV) and hepatitis B virus (HBV).The vaccine was administered to 38 DU, attending three public health centres for drug users in northern Italy, with a three-dose schedule (at 0, 1 and 6 months). The vaccine was well tolerated: only one adverse reaction (fever) was recorded after the 110 doses administered (0.9%). The vaccine schedule was completed successfully in 35 cases (92.1%). At month 8, in 34 subjects (89.5%) antibody response was evaluated: all showed seroprotection for HAV and in 33 subjects (97.1%) for HBV.The vaccine, studied for the first time in DUs, proved to be safe, well accepted and immunogenic; anti-HAV response was 1272 mIU/ml and 1726 mIU/ml for anti-HBV, titres lower than reported in literature for the general population. This study suggests that DUs who are HAV/HBV-negative could be vaccinated with combined vaccine. [ABSTRACT FROM AUTHOR]

Objective: Estimate cost-effectiveness of vaccination against hepatitis A virus (HAV) for children of ethnic minorities in Amsterdam. Background: Pharmaco-economic analysis is relevant for motivating reimbursement of vaccination costs in the framework of a programmatic approach to vaccination of ethnic minorities. Design: Pharmaco-economic modeling. Method: In cost-effectiveness analysis, costs, benefits and health gains were estimated for a large-scale HAV-vaccination for children of Turkish and Maroccan origin. Analysis was performed from the societal perspective, as recommended in the Dutch guidelines for pharmaco-economic research. This implies that indirect costs of production losses are included in the analysis. Cost-effectiveness was expressed in net costs per adult HAV-infection averted in incremental and aggregate analysis. Incremental analysis compares targeted vaccination with the current limited-scale HAV-vaccination that exists, whereas aggregate analysis compares targeted vaccination with the sheer absence of vaccination. Results: Net aggregate costs of targeted HAV-vaccination for Turkish and Maroccan children in Amsterdam amounts to €61.000. Cost-effectiveness was estimated, in aggregate and incremental analysis, at €13.500 and 11.100 respectively per adult HAV-infection averted. Uni- and multivariate sensitivity analyses show that major impact on cost-effectiveness may be expected from reductions in the vaccine price through economies of scale. Probabilistic sensitivity analysis indicates possible large fluctuations in cost-effectiveness from 1 year to another, related to varying incidence of disease. Conclusion: HAV-vaccination for children from ethnic minorities in Amsterdam is not cost saving, but may have a favourable cost-effectiveness. Such a vaccination program fits into the recent Dutch policy of specific vaccinations directed at groups of ethnic minorities, such as for hepatitis B. [Copyright &y& Elsevier]

Congenital or acquired absence of the spleen and functional hyposplenism are associated with abnormalities of host defence such as an increased susceptibility to infection with encapsulated bacteria. The effects of the lack of the spleen on cell-mediated immunity are largely unknown. In the present study we have investigated peripheral blood lymphocyte subpopulations in healthy adults who had undergone splenectomy because of severe abdominal trauma > 4 years before the study. The results show a significant reduction in the percentage of CD4+ T cells due to a selective and long-term decrease in the percentage of CD4+CD45RA+ lymphocytes, the CD4+ T-cell subset mainly involved in primary immune responses to newly encountered antigens. Levels of the reciprocal CD45RO+CD4+ T-cell subset were comparable between splenectomized and control individuals, as were lymphoproliferative responses and IFN-gamma production to recall antigens. Decreased levels of CD4+CD45RA+ cells were accompanied by an impairment in primary immune responsiveness, as assessed by investigating T-cell proliferation to stimulation with keyhole limpet haemocyanin and by measuring antibody responses following primary immunization with a clinically relevant T-dependent antigen, hepatitis A vaccine, in vivo. These findings suggest a possible role of the spleen in the generation, maintenance and/or differentiation of naive, unprimed T cells or their precursors, which might have a possible functional relevance for primary immune responses following splenectomy. [ABSTRACT FROM AUTHOR]

We retrospectively analysed 33 children and adolescents who had been hospitalized in a liver transplant unit within the previous 10 years for acute liver failure (ALF). The patients’ age varied between 2 months and 15 years of age (median 6.2 ± 5.3), and 21 (63%) were male. Thirteen patients (39%) were immunoglobulin-M anti-hepatitis A virus (HAV) sero-positive. Eleven cases (33%) had an undetermined aetiology. The 13 children with HAV ALF were between 17 months and 15.6 years of age (median 5.8 ± 4.6) and eight were male (61.5%). All were on a list for urgent liver transplant. Of these, five (38%) died while waiting for a liver. Only one patient recovered spontaneously. Seven patients received a liver transplant; three died in the immediate postoperative period and one died 45 days after transplant. Three children are alive 1, 2 and 5 years after transplant. We conclude that HAV was the most frequent cause of ALF, which had high mortality even when a liver transplant was possible. The results support universal HAV vaccination in this area. [ABSTRACT FROM AUTHOR]

We evaluated immunogenicity and reactogenicity of an inactivated, combined hepatitis A/B candidate vaccine in 50 seronegative volunteers. Each volunteer received a total of three doses of vaccine (720 EIU HAV and 20 μg HBs antigen) according to a 0, 1 and 6 month vaccination schedule. One month after the first injection, the seroconversion rate was 90% (45/50) for anti-HAV and 28% (14/50) for anti-HBs, respectively. After the booster dose, at month 7, the seroconversion rate was as high as 100% (49/49) for anti-HAV and 94% (46/49) for anti-HBs. The geometric mean titres increased with each dose of vaccine administered. Mild, and mostly local side effects were reported in 54% of the volunteers after the first injection and in less than 10% after the third injection. Our results show that this inactivated, candidate hepatitis A/B vaccine is highly immunogenic and well-tolerated. [ABSTRACT FROM AUTHOR]

Background: Infection with hepatitis A and hepatitis B virus can increase the risk of morbidity and mortality in persons with chronic liver disease (CLD). The Advisory Committee on Immunization Practices recommends hepatitis A (HepA) and hepatitis B (HepB) vaccination for persons with CLD., Methods: Data from the 2014 and 2015 National Health Interview Surveys (NHIS), nationally representative, in-person interview surveys of the non-institutionalized US civilian population, were used to assess self-reported HepA (≥1 and ≥2 doses) and HepB vaccination (≥1 and ≥3 doses) coverage among adults who reported a chronic or long-term liver condition. Multivariable logistic regression was used to identify factors independently associated with HepA and HepB vaccination among adults with CLD., Results: Overall, 19.4% and 11.5% of adults aged ≥ 18 years with CLD reported receiving ≥1 dose and ≥2 doses of HepA vaccine, respectively, compared with 14.7% and 9.1% of adults without CLD (p < .05 comparing those with and without CLD, ≥1dose). Age, education, geographic region, and international travel were associated with receipt of ≥2 doses HepA vaccine among adults with CLD. Overall, 35.7% and 29.1% of adults with CLD reported receiving ≥1 dose and ≥3 doses of HepB vaccine, respectively, compared with 30.2% and 24.7% of adults without CLD (p < .05 comparing those with and without CLD, ≥1 dose). Age, education, and receipt of influenza vaccination in the past 12 months were associated with receipt of ≥3 doses HepB vaccine among adults with CLD. Among adults with CLD and ≥10 provider visits, only 13.8% and 35.3% had received ≥2 doses HepA and ≥3 doses HepB vaccine, respectively., Conclusions: HepA and HepB vaccination among adults with CLD is suboptimal and missed opportunities to vaccinate occurred. Providers should adhere to recommendations to vaccinate persons with CLD to increase vaccination among this population., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Hepatitis A and B disease burden persists in the US. We assessed hepatitis A and hepatitis B vaccination series completion rates among 350,240 commercial/Medicare and 12,599 Medicaid enrollees aged ≥19 years. A vaccination series was considered as completed provided that the minimum interval between doses, as defined by the CDC, and the minimum number of doses were reached. We stratified completion rates by vaccine type (i.e. monovalent or bivalent) at initial vaccination for each cohort. In the commercial/Medicare cohort, the series completion rate was 32.0% for hepatitis A and 39.6% for hepatitis B among those who initiated with a monovalent vaccine, and it was 36.2% for hepatitis A and 48.9% for hepatitis B among those who initiated with a bivalent vaccine. In the Medicaid cohort, the series completion rate was 21.0% for hepatitis A and 24.0% for hepatitis B among those who initiated with a monovalent vaccine, and it was 19.0% for hepatitis A and 24.6% for hepatitis B among those who initiated with a bivalent vaccine. In conclusion, hepatitis A and B vaccination series completion rates were low, and appeared to be lower among Medicaid than among commercial/Medicare enrollees. Commercial/Medicare enrollees who initiated with a bivalent vaccine had higher series completion rates than those who initiated with monovalent vaccines - an observation that was not made among Medicaid enrollees.

Vaccination is an effective strategy to prevent and control the transmission of hepatitis A. Hepatitis A immunization program has been taken into effect since 2001 in Tianjin, China. This study evaluated the effectiveness of strategies in the prevention and control of hepatitis A. Data of serological survey, annual hepatitis A incidence, immunization coverage and the positive rate of hepatitis A IgG before and after the immunization program in residents under 15 years old were used to do the analysis. The results indicated that hepatitis A vaccine induced a striking decrease of hepatitis A incidence and a significant increase in the positive rate of anti-HAV IgG among the children younger than 15 years old. Hepatitis A vaccination in children was proved to be effective in the prevention and control of hepatitis A in Tianjin, China.

In countries with advanced economies better health and hygiene conditions, along with the introduction, in some cases, of global vaccination, have relegated most viral hepatitis to marginal social groups and, in particular, drug users (DUs). The availability of safe and effective vaccines for hepatitis A virus (HAV) and B (HBV) may play a major role in combating this phenomenon. Despite the availability of a safe and effective vaccine for over a decade and the recommendations of international health organizations, vaccinations against HAV among DUs are not as widely known and available as are HBV vaccinations. The purpose of this review article is to present the most significant data in the literature on the prevalence of HAV among DUs and the role of targeted vaccination. To our knowledge, the present article is the first to solely deal with vaccination against HAV in DUs. Immunization after the administration of anti-HAV vaccine has been demonstrated in DUs even if they have responded significantly less than either the general population or carriers of chronic liver disease. All the vaccines were well tolerated and adherence to the vaccine schedule was good. Further studies are needed to optimize the timing and doses of vaccine to be administered to DUs, especially to assess adherence and antibody persistence. Vaccination campaigns are feasible among DUs and have proven to be highly cost-effective.

Aim: To determine the seroprevalence of anti-hepatitis A virus (HAV) antibodies in patients with chronic liver disease (CLD) and to justify the need for hepatitis A vaccination., Methods: Patients (n = 119) were enrolled between July and September 2009. The diagnosis of CLD was based on the presence of viral markers for more than 6 mo. The diagnosis of liver cirrhosis was based on clinical, biochemical and radiological profiles. Patient serum was tested for anti-HAV IgG., Results: The overall anti-HAV seroprevalence was 88.2%. The aetiology of CLD was hepatitis B in 96 patients (80.7%) and hepatitis C in 23 patients (19.3%). Mean age was 44.4 ± 14 years. Patients were grouped according to age as follows: 24 (20.2%) patients in the 21-30 years age group, 22 (18.5%) in the 31-40 years age group, 31 (26.1%) in the 41-50 years age group, 23 (19.3%) in the 51-60 years age group and 19 (16.0%) patients aged greater than 60 years, with reported seroprevalences of 66.7%, 95.5%, 93.5%, 91.3% and 94.7%, respectively. There was a marked increase of seroprevalence in subjects older than 30 years (P = 0.001)., Conclusion: Our study demonstrated that patients aged greater than 30 years of age were likely to have natural immunity to hepatitis A. Therefore, hepatitis A vaccination may not be routinely required in this age group.