Cost-effectiveness of hepatitis A vaccination in children, adolescents, and adults

Heterogeneity in Jail Nursing Medical Intake Forms: A Content Analysis

Despite high prevalence of infectious diseases and substance use disorders in jails, there are limited guidelines for the nursing intake process in this setting. We performed a content analysis of nursing intake forms used at each of the 14 Massachusetts county jails, focusing on infectious disease and substance use disorder. Only 85% of jails offered HIV testing during nursing intake and 50% of jails offered hepatitis C testing. Preventive interventions such as vaccines or pre-exposure prophylaxis therapy were infrequently offered during nursing intake. Screening for substance use disorder was present on the majority of intake forms, but only 23% of intake forms inquired about ongoing medication-assisted treatment for opioid use disorder. The results reflect heterogeneity in nursing intake forms, highlighting missed opportunities for public health interventions.

Cost-effectiveness of a comprehensive immunization program serving high-risk, uninsured adults

Despite the numerous social and economic benefits of vaccination, adult immunization rates fall far short of recommended levels costing the United States $9 billion annually in health care expenditures and reduced productivity. While it is well recognized that childhood immunization is highly cost-effective, the economic impact of adult immunization programs varies by disease and is influenced by population demographics. This study aimed to assess the cost-effectiveness of a comprehensive adult immunization program serving high-need populations delivered by a local health department (LHD) in partnership with community organizations. We modeled incremental cost-effectiveness taking the payer perspective of each vaccine separately in simulated cohorts of 100,000 over a 20-year horizon using data provided by the LHD and data from the published literature. We adjusted the results to align with actual program delivery and used them to estimate an incremental cost-effectiveness ratio (ICER) for the entire program. We assessed the effects of varying our base model parameters in univariate sensitivity analyses. We discounted benefits and life years saved (LYS) at 3% and adjusted results to 2016 US$. Four of seven disease models were cost-effective (using a $100,000 CE threshold) with ICERS ranging from $14,260 to $79,022/LYS. Sensitivity analyses did not substantially impact the results. The ICER for program as a whole was $67,940/LYS. A community-delivered comprehensive immunization program serving uninsured, low income, high-risk adults is a cost-effective investment even when most do not receive the full regimen of some vaccines.

Hepatitis A virus seroprevalence in South Africa - Estimates using routine laboratory data, 2005-2015

INTRODUCTION

South Africa is considered highly endemic for hepatitis A virus (HAV) although few seroprevalence studies have been conducted over the past two decades. The World Health Organization recommends integrating HAV vaccination into national childhood immunization schedules where there is transition from high to intermediate endemicity. As a means of gauging age-specific rates of infection, we report HAV seroprevalence rates among specimens tested for HAV serology within South Africa's public health sector from 2005-2015.

MATERIALS AND METHODS

Hepatitis A serology results (Anti-HAV IgM, IgG and total antibody) from 2005-2015 were extracted from South Africa's National Health Laboratory Service's Corporate Data Warehouse (NHLS CDW), the central data repository of all laboratory test-sets within the public health sector. Results were extracted according to test-set, result, date of testing, health facility, name, surname, age, and sex. Anti-HAV IgG results were merged with total antibody results to reflect anti-HAV seroprevalence. Testing volume, positivity rates and age-specific anti-HAV seroprevalence rates by year and geographic distribution are described.

RESULTS AND DISCUSSION

A total of 501 083 HAV IgM results were retrieved, of which 16 423 (3.3%) were positive, 484 259 (96.6%) negative and 401 (0.1%) equivocal; and 34 710 HAV total antibody/IgG tests of which 30 675 (88.4%) were positive, 4 020 (11.6%) negative and 15 equivocal. Whereas IgM positivity was highest among the 1-4 year age group (33.5%) and lowest among patients >45 years (<0.5%), total antibody positivity ranged from its lowest level of 52.7% in the 1-4 year age group increasing to levels of >90% only after 25 years of age.

CONCLUSION

Anti-HAV total antibody testing within the South African public health sector demonstrates seroprevalence rates reach levels >90% only in adulthood, suggesting South Africa could be in transition from high to intermediate endemicity. Prospective studies with geographically representative sampling are required to confirm these findings and evaluate provincial and urban/rural heterogeneity.

Model Comparisons of the Effectiveness and Cost-Effectiveness of Vaccination: A Systematic Review of the Literature

OBJECTIVES

To describe all published articles that have conducted comparisons of model-based effectiveness and cost-effectiveness results in the field of vaccination. Specific objectives were to 1) describe the methodologies used and 2) identify the strengths and limitations of the studies.

METHODS

We systematically searched MEDLINE and Embase databases for studies that compared predictions of effectiveness and cost-effectiveness of vaccination of two or more mathematical models. We categorized studies into two groups on the basis of their data source for comparison (previously published results or new simulation results) and performed a qualitative synthesis of study conclusions.

RESULTS

We identified 115 eligible articles (only 5% generated new simulations from the reviewed models) examining the effectiveness and cost-effectiveness of vaccination against 14 pathogens (69% of studies examined human papillomavirus, influenza, and/or pneumococcal vaccines). The goal of most of studies was to summarize evidence for vaccination policy decisions, and cost-effectiveness was the most frequent outcome examined. Only 33%, 25%, and 3% of studies followed a systematic approach to identify eligible studies, assessed the quality of studies, and performed a quantitative synthesis of results, respectively. A greater proportion of model comparisons using published studies followed a systematic approach to identify eligible studies and to assess their quality, whereas more studies using new simulations performed quantitative synthesis of results and identified drivers of model conclusions. Most comparative modeling studies concluded that vaccination was cost-effective.

CONCLUSIONS

Given the variability in methods used to conduct/report comparative modeling studies, guidelines are required to enhance their quality and transparency and to provide better tools for decision making.

Hepatitis A Is a Health Hazard for Iranian Pilgrims Who Go to Holly Karbala: A Preliminary Report

BACKGROUND

Iraq is a highly endemic area for the prevalence of hepatitis A and annually hosts a large number of Iranian pilgrims, most of whom are susceptible to infection with the hepatitis A virus (HAV).

OBJECTIVES

This study reports the health hazard of hepatitis A for Iranian pilgrims who go to holly Karbala from the Mazandaran province.

PATIENTS AND METHODS

In this cross-sectional study, the data of all patients with acute hepatitis A admitted in the Razi teaching hospital from November 23, 2014 to January 24, 2015, with a history of recently returning from holly Karbala or being exposed to Karbala pilgrims, were registered.

RESULTS

A total number of nine patients were registered. Seven patients were male and two were female. The mean age was 30.11 ± 10.09.Two patients were from the same family. All patients had typical symptoms of acute hepatitis A. None of the patients died nor did fulminant occur in any patients. In addition, all patients were treated with supportive treatment and subsequently recovered.

CONCLUSIONS

This number of pilgrim patients with acute hepatitis A from a single province compels us to conduct more evaluations and follow up monitoring on all persons travelling to Karbala and be sensitive to early diagnoses of the pilgrims. In the future, it is important to be mindful of administering the HAV vaccine and Ig.

Pattern of Hepatitis A Virus Epidemiology in Nursing Students and Adherence to Preventive Measures at Two Training Wards of a University Hospital

BACKGROUND

Nursing students can be exposed to patients with hepatitis A virus (HAV) and can represent a vehicle of transmission both for health personnel, patients and relatives.

OBJECTIVES

The aim of this study was to assess the risk of HAV infection in nursing students during their internship.

PATIENTS AND METHODS

A seroprevalence survey on HAV infection was performed on nursing students at the Cagliari university-hospital, together with the assessment of the compliance to preventive measures to decrease the risk of infection during their internship. Blood specimens were obtained from 253 students. All serum samples were tested for anti-HAV antibodies (IgG) by the enzyme-linked immunosorbent assay (ELISA). Compliance to preventive measures was recorded by trained personnel.

RESULTS

Overall HAV seropositivity in nursing students (mean age 24, range 17 - 45 years) was 3%. Compliance to preventive measures was not uniform (6% - 76%) and extremely low in some specific measures targeted to decrease the oral-fecal transmission.

CONCLUSIONS

The high proportion of susceptible nursing students can contribute to an increase in the risk of nosocomial transmission, especially when specific preventive measures are not completely applied. Nursing education packages, before starting medical internship, should be implemented in order to increase their compliance to preventive measures, especially in wards at higher risk. Vaccination should be considered in wards at higher risk.

Trends in disease and complications of hepatitis A virus infection in the United States, 1999-2011: a new concern for adults

BACKGROUND

In recent years, few US adults have had exposure and resultant immunity to hepatitis A virus (HAV). Further, persons with liver disease have an increased risk of adverse consequences if they are infected with HAV.

METHODS

This study used 1999-2011 National Notifiable Diseases Surveillance System and Multiple Cause of Death data to assess trends in the incidence of HAV infection, HAV-related hospitalization, and HAV-related mortality.

RESULTS

During 1999-2011, the incidence of HAV infection declined from 6.0 cases/100 000 to 0.4 cases/100 000. Similar declines were seen by sex and age, but persons aged ≥80 years had the highest incidence of HAV infection in 2011 (0.8 cases/100 000). HAV-related hospitalizations increased from 7.3% in 1999 to 24.5% in 2011. The mean age of hospitalized cases increased from 36.0 years in 1999 to 45.1 years in 2011. While HAV-related mortality declined, the mean age at death among decedents with HAV infection increased from 48.0 years in 1999 to 76.2 years in 2011. The median age range of decedents who had HAV infection and a liver-related condition was 51.0 to 68.0 years.

CONCLUSIONS

Although vaccine-preventable, HAV-related hospitalizations increased greatly, mostly among adults, and liver-related conditions were frequently reported among HAV-infected individuals who died. Public health efforts should focus on the need to assess protection from hepatitis A among adults, including those with liver disease.

Public Health Impact and Cost-Effectiveness of Hepatitis A Vaccination in the United States: A Disease Transmission Dynamic Modeling Approach

OBJECTIVE

To assess the population-level impact and cost-effectiveness of hepatitis A vaccination programs in the United States.

METHODS

We developed an age-structured population model of hepatitis A transmission dynamics to evaluate two policies of administering a two-dose hepatitis A vaccine to children aged 12 to 18 months: 1) universal routine vaccination as recommended by the Advisory Committee on Immunization Practices in 2006 and 2) Advisory Committee on Immunization Practices's previous regional policy of routine vaccination of children living in states with high hepatitis A incidence. Inputs were obtained from the published literature, public sources, and clinical trial data. The model was fitted to hepatitis A seroprevalence (National Health and Nutrition Examination Survey II and III) and reported incidence from the National Notifiable Diseases Surveillance System (1980-1995). We used a societal perspective and projected costs (in 2013 US $), quality-adjusted life-years, incremental cost-effectiveness ratio, and other outcomes over the period 2006 to 2106.

RESULTS

On average, universal routine hepatitis A vaccination prevented 259,776 additional infections, 167,094 outpatient visits, 4781 hospitalizations, and 228 deaths annually. Compared with the regional vaccination policy, universal routine hepatitis A vaccination was cost saving. In scenario analysis, universal vaccination prevented 94,957 infections, 46,179 outpatient visits, 1286 hospitalizations, and 15 deaths annually and had an incremental cost-effectiveness ratio of $21,223/quality-adjusted life-year when herd protection was ignored.

CONCLUSIONS

Our model predicted that universal childhood hepatitis A vaccination led to significant reductions in hepatitis A mortality and morbidity. Consequently, universal vaccination was cost saving compared with a regional vaccination policy. Herd protection effects of hepatitis A vaccination programs had a significant impact on hepatitis A mortality, morbidity, and cost-effectiveness ratios.

Vaccinating the inflammatory bowel disease patient

Current therapeutic options for patients with inflammatory bowel disease (IBD) include several agents that can alter their immune response to infections. Effective vaccines exist and offer protection against a number of infectious diseases. However, recent data has shown that IBD patients are inadequately vaccinated and, as a result, at risk to develop certain preventable infections. Furthermore, gastroenterologists' knowledge regarding the appropriate immunizations to administer to their IBD patients is suboptimal. This review article focuses on the current immunization schedule for the IBD patient and stresses the important role of the gastroenterologist as an active participant in the management of vaccination in their IBD patients.

The appropriate use of vaccines in patients with inflammatory bowel disease

An increasing majority of patients with inflammatory bowel disease (IBD) will be placed on immunosuppressive medications, thus increasing their susceptibility to infections. Although many of these infections are preventable through the use of vaccinations, vaccines seem to be underutilized in IBD patients. This article reviews current immunization guidelines and makes evidence-based recommendations regarding the appropriate use of vaccinations for patients with IBD.

Hepatitis A immunity in the District of Aveiro (Portugal): an eleven-year surveillance study (2002-2012)

Hepatitis A is a common viral liver disease and brings serious health and economic problems as its epidemiologic pattern changes over time. National serosurveys from developed countries have indicated a decline in HAV (hepatitis A virus) seroprevalence over time due to the improvement of economic and sanitation levels. The hepatitis A virus (HAV) immunity rate was surveyed throughout an eleven-year period by sex and age group in Aveiro District. In this retrospective study, blood samples from patients of Aveiro District, in ambulatory regime, collected at the Clinical Analysis Laboratory Avelab between 2002 and 2012 were screened for the presence of antibodies against HAV antigen using a chemiluminescence immunoassay. The global immunity (positive total anti-HAV) was 60% and only 0.3% of the patients presented recent infection by HAV (positive IgM anti-HAV). The HAV immunity was age-dependent (p < 0.05), but no significant differences (p > 0.05) between sexes were observed. The immunity was similar throughout the study period (p > 0.05). The results of this study indicate that young people (especially under 25 years old) from District of Aveiro are susceptible to HAV infection, constituting a high risk group. The elderly should be also a concern in the future of Hepatitis A infection.

Methodological issues and new developments in the economic evaluation of vaccines

The application of economic evaluation in healthcare, including vaccination programs, has increased exponentially since the 1980s. There are a number of aspects of economic evaluation of vaccine programs that present particular challenges to the analyst. These include the development of the appropriate epidemiological models from which to estimate the costs and benefits; the accurate prediction of uptake rates; the incorporation of quality adjusted survival gains; and the inclusion of intangible but nonetheless important benefits and costs associated with infectious disease and vaccination. The estimation of marginal intervention costs presents specific difficulties, especially for multivalent vaccines and valuing costs and benefits over time is heavily influenced by the choice of discount rate, which is still a controversial topic. Developments in the next 5 years are likely to address all of these issues and result in more sophisticated and accurate models of vaccination programs.

Economic evaluations of hepatitis A vaccination in middle-income countries

Economic evaluations of hepatitis A vaccination are important to assist national and international policy makers in different jurisdictions on making effective decisions. Up to now, a comprehensive review of the potential health and economic benefits on hepatitis A vaccination in middle-income countries (MICs) has not been performed yet. In this study, we reviewed the literature on the cost-effectiveness of hepatitis A vaccination in MICs. Most of the studies confirmed that hepatitis A vaccination was cost effective or even cost saving under certain conditions. We found that vaccine price, medical costs, incidence and discount rate were the most influential parameters on the sensitivity analyses. Vaccine price has been shown as a barrier for MICs in implementing universal vaccination of hepatitis A. Given their relatively limited financial resources, implementation of single-dose vaccination could be considered. Despite our findings, we argue that further economic evaluations in MICs are still required in the near future.

Acute cholestatic hepatitis a virus infection presenting with hemolytic anemia and renal failure: a case report

Hepatitis A virus is the most common acute viral hepatitis worldwide with approximately 1.5 million cases annually. Hepatitis A virus infection in general is self-limited. In rare cases, hepatitis A virus infection may cause renal failure, hemolytic anemia, and/or cholestasis. We report the first case of acute cholestatic hepatitis A virus infection complicated by hemolytic anemia, and renal failure in one patient. A 42-year-old Caucasian male presented with cholestasis, hemolytic anemia and renal failure after consuming street tacos in Central and South America while on a business trip. His protracted course required corticosteroid therapy, multiple sessions of plasma exchange, and numerous units of packed red blood cells. This case demonstrates the importance of vaccination in high-risk adults. A prompt diagnosis of acute hepatitis A virus infection is essential, as uncommon presentations may delay diagnosis leading to permanent morbidity and potentially death in fulminant cases. We also demonstrate the efficacy of treatment of cholestatic hepatitis A virus infection, hemolytic anemia, and renal failure with corticosteroids and plasma exchange.

Review of 10 years of marketing experience with Chinese domestic inactivated hepatitis A vaccine Healive®

In 2002, the first Chinese domestic preservative-free inactivated hepatitis A vaccine, Healive®, was introduced in China. It is highly immunogenic, and provides lasting protection in healthy individuals and generates protective levels of antibodies in other at-risk individuals. Over 10 years since its first licensure, postmarketing surveillance data have confirmed the outstanding safety profile of the vaccine. Comparative clinical trials indicated that Healive® induce equal or similar immunogenicity with other currently available inactivated hepatitis A vaccines and are interchangeable for the course of HAV immunization in Chinese children. The vaccine is effective in curbing outbreaks of hepatitis A due to rapid seroconversion and the long incubation period of the disease. Additional issues surrounding the use of the vaccine are also reviewed.

Age-specific seroprevalence of anti-hepatitis a antibody among 1-30 years old population of savadkuh, mazandaran, iran with literature review

BACKGROUND

To determine age-specific seroprevalence rates of hepatitis A virus (HAV) immunoglobulin G (IgG) antibody in Savadkuh district, Mazandaran province, north of Iran, as well as to compare the collected data with earlier seroprevalence studies in the region and Iran in order to draw a proper epidemiological pattern for HAV infection in the country.

OBJECTIVES

This study aimed to assess an age-specific HAV seroprevalence among 1- to 30-yearold people in Savadkuh, a less developed district of Mazandaran province, north of Iran.

PATIENTS AND METHODS

The study participants were 984 subjects who aged from one to 30 years and were residents of rural and urban areas of Savadkuh. They were selected using cluster sampling method and divided into five age groups: 1-2.9 (316 cases), 3-6.9 (254 cases), 7-10.9 (201 cases), 11-17.9 (115 cases), and 18-30 (98 cases). Anti-HAV antibody was measured by ELISA method. Seroprevalence rates among different age groups and their relationship to residency, educational levels of parents, water supply, and waste water disposal system was analyzed using chi-squared test.

RESULTS

Overall seroprevalence rate was 19.20 % with no significant difference between rural and urban residents. The seroprevalence rates increased significantly with age: from 5.7 % in age group 1-2.9 year to 34.8 % in adolescents, and to 68.4 % among young adults (P < 0.0001); regardless of significant differences in educational levels among parents of residents in two areas it did not affect seroprevalence rates. Findings of this study and reviewing other reports from the region and the country suggest an epidemiological shift towards lower rates of anti-HAV antibody seroprevalence.

CONCLUSIONS

It appears that anti-HAV antibody seroprevalence rate has been declining among Iranians and thereby more children would be susceptible to this infection. This would necessitate revising current strategies of preventative measures in Mazandaran and Iran.

Cost-effectiveness of hepatitis A vaccination for individuals with chronic hepatitis C

The incidence of hepatitis A infection in the United States has decreased dramatically in recent years because of childhood immunization programs. A decision analysis of the cost-effectiveness of hepatitis A vaccination for adults with hepatitis C was conducted. No vaccination strategy is cost-effective for adults with hepatitis C using the recent lower anticipated hepatitis A incidence, private sector costs, and a cost-effectiveness criterion of $100,000/QALY. Vaccination is cost-effective only for individuals who have cleared the hepatitis C virus when Department of Veterans Affairs costs are used. The recommendation to vaccinate adults with hepatitis C against hepatitis A should be reconsidered.

Vaccination strategies against hepatitis A in travelers older than 40 years: an economic evaluation

BACKGROUND

In recent years, the number of travelers aged >40 years who acquire hepatitis A while traveling has increased. Therefore, there is a need to review hepatitis A vaccination protocols in travelers. The aims of the study were to assess immunity levels to hepatitis A virus (HAV) in international travelers >40 years and to determine the least costly immunization strategy.

METHODS

A serological examination of HAV antibodies in 427 international travelers aged >40 years traveling endemic zones was carried out. The prevalence of antibodies in each age group was assessed. The costs of two preventive strategies, direct vaccination of all subjects (independent of the immune status) or screening and subsequent vaccination of susceptible subjects were compared. The critical value of prevalence (CVP) (the value at which the costs for the two strategies are equal) was calculated.

RESULTS

Total prevalence of HAV antibodies was 78.9% [95% confidence interval (CI): 74.8-82.5] and was 80.0% (95% CI: 73.8-85.2) in men and 77.9% (95% CI: 71.9-83.2) in women. There was a positive association with age. In the 40 to 49, 50 to 59, 60 to 69, and 70 to 95 years age groups, the prevalence rates were 62.6 (95% CI: 53.8-71.5), 76.8 (95% CI: 70.0-82.7), 91.7 (95% CI: 85.2-95.6), and 97.5% (95% CI: 87.4-99.6), respectively. The CVP was 58.4% using two doses of vaccine.

CONCLUSIONS

The CVP was lower than the prevalence rate found in our international travelers. Therefore, we recommend systematic screening for HAV antibodies before selective vaccination of international travelers aged >40 years traveling to hepatitis A endemic zones.

Multilevel analysis of hepatitis A infection in children and adolescents: a household survey in the Northeast and Central-west regions of Brazil

Background The objectives were to estimate the prevalence of hepatitis A among children and adolescents from the Northeast and Midwest regions and the Federal District of Brazil and to identify individual-, household- and area-levels factors associated with hepatitis A infection.

Methods This population-based survey was conducted in 2004–2005 and covered individuals aged between 5 and 19 years. A stratified multistage cluster sampling technique with probability proportional to size was used to select 1937 individuals aged between 5 and 19 years living in the Federal capital and in the State capitals of 12 states in the study regions. The sample was stratified according to age (5–9 and 10- to 19-years-old) and capital within each region. Individual- and household-level data were collected by interview at the home of the individual. Variables related to the area were retrieved from census tract data. The outcome was total antibodies to hepatitis A virus detected using commercial EIA. The age distribution of the susceptible population was estimated using a simple catalytic model. The associations between HAV infection and independent variables were assessed using the odds ratio and corrected for the random design effect and sampling weight. Multilevel analysis was performed by GLLAMM using Stata 9.2.

Results The prevalence of hepatitis A infection in the 5–9 and 10–19 age-group was 41.5 and 57.4%, respectively for the Northeast, 32.3 and 56.0%, respectively for the Midwest and 33.8 and 65.1% for the Federal District. A trend for the prevalence of HAV infection to increase according to age was detected in all sites. By the age of 5, 31.5% of the children had already been infected with HAV in the Northeast region compared with 20.0% in the other sites. By the age of 19 years, seropositivity was ∼70% in all areas. The curves of susceptible populations differed from one area to another. Multilevel modeling showed that variables relating to different levels of education were associated with HAV infection in all sites.

Conclusion The study sites were classified as areas with intermediate endemicity area for hepatitis A infection. Differences in age trends of infection were detected among settings. This multilevel model allowed for quantification of contextual predictors of hepatitis A infection in urban areas.

Cost-effectiveness analysis of behavioral interventions to improve vaccination compliance in homeless adults

AIMS

To estimate the cost-effectiveness of three behavioral interventions provided to enhance hepatitis A virus (HAV) and hepatitis B virus (HBV) joint vaccination (HAV/HBV) compliance among homeless persons living in Los Angeles County.

SCOPE

A cost-effectiveness analysis (CEA) based on data from a randomized trial where the costs and compliance data from the trial are incorporated into two Markov models, simulating the natural history of acute and chronic hepatitis infection, following HAV/HBV vaccination.

CONCLUSIONS

Reductions in HBV-related disease is cost-effective to society and is associated with substantial improvements in quality of life.

A statistical model to estimate the impact of a hepatitis A vaccination programme

A program of routine hepatitis A+B vaccination in preadolescents was introduced in 1998 in Catalonia, a region situated in the northeast of Spain. The objective of this study was to quantify the reduction in the incidence of hepatitis A in order to differentiate the natural reduction of the incidence of hepatitis A from that produced due to the vaccination programme and to predict the evolution of the disease in forthcoming years. A generalized linear model (GLM) using negative binomial regression was used to estimate the incidence rates of hepatitis A in Catalonia by year, age group and vaccination. Introduction of the vaccine reduced cases by 5.5 by year (p-value<0.001), but there was a significant interaction between the year of report and vaccination that smoothed this reduction (p-value<0.001). The reduction was not equal in all age groups, being greater in the 12-18 years age group, which fell from a mean rate of 8.15 per 100,000 person/years in the pre-vaccination period (1992-1998) to 1.4 in the vaccination period (1999-2005). The model predicts the evolution accurately for the group of vaccinated subjects. Negative binomial regression is more appropriate than Poisson regression when observed variance exceeds the observed mean (overdispersed count data), can cause a variable apparently contribute more on the model of what really makes it.

Cost-effectiveness analyses of vaccination programmes : a focused review of modelling approaches

Cost effectiveness is becoming an increasingly important factor for stakeholders faced with decisions about adding a new vaccine into national immunization programmes versus alternative use of resources. Evaluating cost effectiveness, taking into account the relevant biological, clinical, epidemiological and economic factors of a vaccination programme, generally requires use of a model. This review examines the modelling approaches used in cost-effectiveness analyses (CEAs) of vaccination programmes.After overviewing the key attributes of models used in CEAs, a framework for categorising theoretical models is presented. Categories are based on three main attributes: static/dynamic; stochastic/deterministic; and aggregate/individual based. This framework was applied to a systematic review of CEAs of all currently available vaccines for the period of 1976 to May 2007. The systematic review identified 276 CEAs of vaccination programmes. The great majority (83%) of CEAs were conducted in the setting of high-income countries. Only a few vaccines were widely studied, with 57% of available CEAs being focused on the varicella, influenza, hepatitis A, hepatitis B or pneumococcal vaccine. Several time trends were evident, indicating that the number of vaccine CEAs being published is increasing; the main health outcome measures are moving away from the number of cases prevented towards quality-adjusted and unadjusted life-years gained, and more complex models are beginning to be used. The modelling approach was often not adequately described. Of the 208 CEAs that could be categorized according to the framework, around 90% were deterministic, aggregate-level static models. Although a dynamic transmission model is required to account for herd-immunity effects, only 23 of the CEAs were dynamic. None of the CEAs were individual based. To improve communication about the cost effectiveness of vaccination programmes, we believe the first step is for analysts to be more transparent with each other. A clear description of the model type using consistent terminology and justification for the model choice must begin to accompany all CEAs. As a minimum, we urge modellers to provide an explicit statement about the following attributes: static/dynamic; stochastic/deterministic; aggregate/individual based; open/closed. Where relevant, time intervals (discrete/continuous) and (non)linearity should also be described. Enhanced methods of assessing model performance and validity are also required. Our results emphasize the need to improve modelling methods for CEAs of vaccination programmes; specifically, model choice, construction, assessment and validation.

Do we fully understand the economic value of vaccines?

Although many vaccination strategies are cost-effective, some of the newer vaccines are more expensive and may raise concerns about value for money. However, standard methods of economic evaluation may not adequately assess the true cost-effectiveness of vaccines, with the consequent under-application of vaccine strategies. Therefore, this paper reviews the evidence on cost-effectiveness of vaccines and vaccination strategies for pneumococcal disease, meningococcal disease, Hepatitis A and influenza. In each case the evidence is considered alongside existing vaccination policies in the major developed countries. The paper also highlights areas where traditional economic evaluations may not adequately reflect the value of vaccines.

The cost-effectiveness of universal vaccination of children against hepatitis A in Argentina: results of a dynamic health-economic analysis

BACKGROUND

Socioeconomic improvements can reduce levels of endemic hepatitis A, but conversely increase the burden of disease. Routine childhood vaccination can rapidly control hepatitis A infection rates through the induction of herd immunity, although such programs can be costly.

METHODS

We evaluated the healthcare benefits and cost-effectiveness of a routine childhood vaccination program against hepatitis A in Argentina, using a dynamic model that incorporated the changing epidemiology of infection and the impact of vaccine-induced herd immunity. Demographic, disease, and economic data from Argentina were used where available.

RESULTS

At 95% coverage, the program would reduce the number of hepatitis A infections by 352,405 annually, avoiding 121,587 symptomatic cases and 428 deaths. Substantial healthcare benefits were also observed with vaccination coverage as low as 70%, which would prevent 295,826 infections. Economically, the program would save 23,989,963 US$ annually at 95% coverage, equivalent to 3,429 US$ per life-year gained. The program remained cost-saving in response to variation in factors, including disease-related costs, discount rate, herd immunity level, and rate of decrease of force of infection. The break-even cost per vaccine dose for the society was 25 US$ in the base-case, more than three times the current public cost of 7 US$ per dose.

CONCLUSIONS

Routine childhood vaccination against hepatitis A showed both health benefits and robust economic benefits in this analysis, supporting the recent decision of the Argentine government to implement such a program.

A review of interventions triggered by hepatitis A infected food-handlers in Canada

Background

In countries with low hepatitis A (HA) endemicity, infected food handlers are the source of most reported foodborne outbreaks. In Canada, accessible data repositories of infected food handler incidents are not available. We undertook a systematic review of such incidents to evaluate the extent of viral transmission through food contamination and the scope of post-exposure prophylaxis (PEP) interventions.

Methods

A systematic search of MEDLINE and EMBASE was conducted to identify published reports of incidents in Canada. An expanded search of a news repository (i.e., transcripts from newspapers and newscasts) was also conducted to identify the location and timing of an incident, which was used to retrieve the related report by contacting local public health departments. Data pertaining to case identification, public health risk, PEP interventions, and associated costs was independently abstracted by two reviewers and summarized according to incidents with and without large PEP interventions.

Results

A total of 16 incidents were identified from 1998–2004. There were approximately 3 incidents requiring public notification per year. Only 12.5% of incidents were described in published reports, indicating that published data significantly underestimated the number of incidents and PEP interventions. Data pertaining to the remaining incidents was unpublished, sparse and highly dispersed at the local public health level.

Six of the 16 incidents required large PEP interventions to immunize on average 5000 potentially exposed individuals. Secondary transmission was low. Characteristics of incidents requiring large PEP interventions included potentially infectious food handlers working with uncooked food for a prolonged duration in high-volume grocery stores in high-density urban areas.

Conclusion

Infected food handlers with hepatitis A virus (HAV) requiring public notification are not infrequent in Canada. Published data severely underestimated the burden of PEP intervention. Better and consistent reporting at the local and national level as well as a national data repository should be considered for the management of future incidents.

Hepatitis A vaccines: the growing case for universal immunisation of children

Hepatitis A virus (HAV) infection results in a debilitating, multi-week illness in older children and adults that can be avoided with pre-exposure immunisation. Inactivated HAV vaccines are safe, highly effective and induce long-lasting protection. Immunisation has typically been recommended only for groups at highest risk of infection or complications, with variable success. This paper reviews the outcomes of several new programmes of universal HAV immunisation of children and/or adolescents. These programmes were associated with substantial disease rate reductions, extending beyond the immunised individuals and age groups (herd immunity), and promise additional benefits as immunised cohorts enter adulthood risk groups. Universal programmes are cost-effective, especially when a combined hepatitis A and B vaccine can be used to minimise incremental costs, and deserve wider consideration in developed countries.

Aspectos sociodemográficos da soroprevalência de marcadores do vírus da hepatite A no povoado de Cavunge, região do semi-árido do Estado da Bahia

No Povoado de Cavunge, semi-árido da Bahia, foi realizado estudo sobre as hepatites com objetivo de avaliar a prevalência de portadores de IgG anti-VHA. Foram avaliados 891 moradores e 85,9% foram soropositivos. A prevalência foi semelhante entre os sexos. Na zona urbana houve aumento da prevalência com a idade.

Hepatitis A: a preventable threat

Hepatitis A is a major public health problem, particularly in the pediatric population. Although hepatitis A infection does not cause chronic liver disease, it is associated with significant morbidity. The virus is transmitted primarily by person-to-person contact via the fecal-oral route. The infection can be inapparent, subclinical, anicteric, or icteric. In general, the severity of the disease is inversely correlated with the age of the child. Occasionally, fulminant hepatitis, which is associated with a high mortality rate, may result. The diagnosis of acute hepatitis A is most commonly made through the detection of immunoglobulin M (IgM) anti-hepatitis A antibody. Treatment is generally supportive. General preventive measures include improved standards of hygiene and sanitation. Universal childhood vaccination is the most effective method for eradicating hepatitis A and preventing its transmission.

Public health perspective on vaccine-preventable hepatitis: integrating hepatitis A and B vaccines into public health settings

Hepatitis A and B vaccinations can and should be integrated into public health settings that serve adults at high risk for infection (e.g., sexually transmitted disease and/or human immunodeficiency virus clinics, criminal justice settings), and a policy of universal immunization may be the best way to accomplish this goal in these settings. Although hepatitis vaccines should be given to all susceptible persons at risk, many opportunities to vaccinate adults at high risk are missed, and there are several barriers and challenges to vaccination of adults. These challenges and barriers can be overcome. Successful integration of hepatitis vaccination for adults into existing public health services and clinics has been accomplished across the United States at both state and local levels. Additional funds must be provided for the infrastructure and purchase of vaccines for adults in these settings.

An economic assessment of pre-vaccination screening for hepatitis A and B

OBJECTIVE

The availability of a single vaccine active against hepatitis A and B may facilitate prevention of both infections, but complicates the question of whether to conduct pre-vaccination screening. The authors examined the cost-effectiveness of pre-vaccination screening for several populations: first-year college students, military recruits, travelers to hepatitis A-endemic areas, patients at sexually transmitted disease clinics, and prison inmates.

METHODS

Three prevention protocols were examined: (1) screen and defer vaccination until serology results are known; (2) screen and begin vaccination immediately to avoid a missed vaccination opportunity; and (3) vaccinate without screening. Data describing pre-vaccination immunity, vaccine effectiveness, and prevention costs borne by the health system (i.e., serology, vaccine acquisition, and administration) were derived from published literature and U.S. government websites. Using spreadsheet models, the authors calculated the ratio of prevention costs to the number of vaccine protections conferred.

RESULTS

The vaccinate without screening protocol was most cost-effective in nine of 10 analyses conducted under baseline assumptions, and in 69 of 80 sensitivity analyses. In each population considered, vaccinate without screening was less costly than and at least equally as effective as screen and begin vaccination. The screen and defer vaccination protocol would reduce costs in seven populations, but effectiveness would also be lower.

CONCLUSIONS

Unless directed at vaccination candidates with the highest probability of immunity, pre-vaccination screening for hepatitis A and B immunity is not cost-effective. Balancing cost reduction with reduced effectiveness, screen and defer may be preferred for older travelers and prison inmates.

An economic assessment of pre-vaccination screening for hepatitis A and B

OBJECTIVE

The availability of a single vaccine active against hepatitis A and B may facilitate prevention of both infections, but complicates the question of whether to conduct pre-vaccination screening. The authors examined the cost-effectiveness of pre-vaccination screening for several populations: first-year college students, military recruits, travelers to hepatitis A-endemic areas, patients at sexually transmitted disease clinics, and prison inmates.

METHODS

Three prevention protocols were examined: (1) screen and defer vaccination until serology results are known; (2) screen and begin vaccination immediately to avoid a missed vaccination opportunity; and (3) vaccinate without screening. Data describing pre-vaccination immunity, vaccine effectiveness, and prevention costs borne by the health system (i.e., serology, vaccine acquisition, and administration) were derived from published literature and U.S. government websites. Using spreadsheet models, the authors calculated the ratio of prevention costs to the number of vaccine protections conferred.

RESULTS

The vaccinate without screening protocol was most cost-effective in nine of 10 analyses conducted under baseline assumptions, and in 69 of 80 sensitivity analyses. In each population considered, vaccinate without screening was less costly than and at least equally as effective as screen and begin vaccination. The screen and defer vaccination protocol would reduce costs in seven populations, but effectiveness would also be lower.

CONCLUSIONS

Unless directed at vaccination candidates with the highest probability of immunity, pre-vaccination screening for hepatitis A and B immunity is not cost-effective. Balancing cost reduction with reduced effectiveness, screen and defer may be preferred for older travelers and prison inmates.

Current immunizations for travel

PURPOSE OF REVIEW

International travelers may be at risk from a variety of potentially severe and life-threatening infections. Some of these diseases are preventable, and vaccination remains a cornerstone of travel medicine. Vaccines that are important for international travel are reviewed, in a succinct update based on the most recent literature.

RECENT FINDINGS

Discussed are vaccines for enteric infections (polio, cholera, hepatitis A, and typhoid), as well as those for hepatitis B, Japanese encephalitis, yellow fever, and meningococcal vaccines. The controversial end to the polio eradication campaign and the recognition of vaccine-derived polioviruses are discussed. New monovalent cholera vaccines, including the live attenuated Peru-15 and CVD 103-HgR and the oral killed whole cell B subunit vaccine are reviewed, as well as a new oral bivalent vaccine that may offer protection against Vibrio cholerae 0139. Advances in typhoid vaccination include promising preclinical and clinical trial results of recombinant ZH9 and CVD 908-htrA vaccines, which, in addition to providing protection against typhoid fever, may be useful vectors for heterologous antigens. A growing recognition of rare adverse reactions to the 17D yellow fever vaccine, especially postvaccinal encephalitis, has led to a reassessment of its risks and benefits. Development of a novel chimeric vaccine may improve the safety and efficacy of the current Japanese encephalitis vaccine. Vaccination for meningococcal disease is characterized by the need for polyvalent, conjugate vaccines as well as a product that affords protection against serotype B.

SUMMARY

This travel vaccination review highlights progress in new travel-related vaccine development and updates the reader on issues surrounding licensed products. It will be useful for generalists, infectious disease physicians, and travel medicine specialists.

Prevention of hepatitis A by vaccination

Inactivated hepatitis A vaccines have been available for more than a decade. Characteristics of the vaccines, comparative data among different formulations and the possibility of combination and association with other vaccines are reviewed in this article. Hepatitis A vaccines show high immunogenicity with different schedules and associations, induce long-term protection irrespective of timing of booster dose, and present an excellent safety profile. Pre-exposure efficacy has been demonstrated in large trials and postexposure protection has been described in family contacts of acute cases. The recommendations for the use of hepatitis A vaccines for immunisation campaigns and for targeted groups, such as travellers and people at risk for occupational and iatrogenic exposure or lifestyle behaviours, are discussed. Aspects related to economic analysis of vaccination strategies are also considered.

The cost effectiveness of hepatitis immunization for US college students

Hepatitis B immunization is recommended for all American children, and hepatitis A immunization is recommended for children who live in areas with elevated disease rates. Because hepatitis A and B occur most commonly in young adults, the authors examined the cost effectiveness of college-based vaccination. They developed epidemiologic models to consider infection risks and disease progression and then compared the cost of vaccination with economic, longevity, and quality of life benefits. Immunization of 100,000 students would prevent 1,403 acute cases of hepatitis A, 929 cases of hepatitis B, and 144 cases of chronic hepatitis B. Hepatitis B vaccination would cost the health system $7,600 per quality-adjusted life year (QALY) gained but would reduce societal costs by 6%. Hepatitis A/B vaccination would cost the health system dollar 8,500 per QALY but would reduce societal costs by 12%. Until childhood and adolescent vaccination can produce immune cohorts of young adults, college-based hepatitis immunization can reduce disease transmission in a cost-effective manner.