Policy analysis of the use of hepatitis B, Haemophilus influenzae type b-, Streptococcus pneumoniae-conjugate and rotavirus vaccines in national immunization schedules

Life Course Approach to Vaccination in Bangladesh for meeting the SDG health and health related goals - a commentary

Bangladesh is entering from low-income to lower-middle-income status in 2020, and this will be completed in the next 5 years. With gross national income growing, vaccines will need to be procured through private market for the Expanded Program on Immunization. A cost-benefit analysis is needed to evaluate vaccine demand in different socioeconomic groups in the country, to inform this procurement. Moreover, disease burden studies and awareness of importance of specific vaccines are needed as we move forward. A life-course approach to vaccination may enable whole society to realize the full potential of vaccination and address most significant threats to its success over time.

Inclusion of the value of herd immunity in economic evaluations of vaccines. A systematic review of methods used

OBJECTIVE

The objectives of this review were to identify vaccine economic evaluations that include herd immunity and describe the methodological approaches used.

METHODS

We used Kim and Goldie's search strategy from a systematic review (1976-2007) of modelling approaches used in vaccine economic evaluations and additionally searched PubMed/MEDLINE and Embase for 2007-2015. Studies were classified according to modelling approach used. Methods for estimating herd immunity effects were described, in particular for the static models.

RESULTS

We identified 625 economic evaluations of vaccines against human-transmissible diseases from 1976 to 2015. Of these, 172 (28%) included herd immunity. While 4% of studies included herd immunity in 2001, 53% of those published in 2015 did this. Pneumococcal, human papilloma and rotavirus vaccines represented the majority of studies (63%) considering herd immunity. Ninety-five of the 172 studies utilised a static model, 59 applied a dynamic model, eight a hybrid model and ten did not clearly state which method was used. Relatively crude methods and assumptions were used in the majority of the static model studies.

CONCLUSION

The proportion of economic evaluations using a dynamic model has increased in recent years. However, 55% of the included studies used a static model for estimating herd immunity. Values from a static model can only be considered reliable if high quality surveillance data are incorporated into the analysis. Without this, the results are questionable and they should only be included in sensitivity analysis.

Pneumonia's second wind? A case study of the global health network for childhood pneumonia

Advocacy, policy, research and intervention efforts against childhood pneumonia have lagged behind other health issues, including malaria, measles and tuberculosis. Accelerating progress on the issue began in 2008, following decades of efforts by individuals and organizations to address the leading cause of childhood mortality and establish a global health network. This article traces the history of this network's formation and evolution to identify lessons for other global health issues. Through document review and interviews with current, former and potential network members, this case study identifies five distinct eras of activity against childhood pneumonia: a period of isolation (post WWII to 1984), the duration of WHO's Acute Respiratory Infections (ARI) Programme (1984-1995), Integrated Management of Childhood illness's (IMCI) early years (1995-2003), a brief period of network re-emergence (2003-2008) and recent accelerating progress (2008 on). Analysis of these eras reveals the critical importance of building a shared identity in order to form an effective network and take advantage of emerging opportunities. During the ARI era, an initial network formed around a relatively narrow shared identity focused on community-level care. The shift to IMCI led to the partial dissolution of this network, stalled progress on addressing pneumonia in communities and missed opportunities. Frustrated with lack of progress on the issue, actors began forming a network and shared identity that included a broad spectrum of those whose interests overlap with pneumonia. As the network coalesced and expanded, its members coordinated and collaborated on conducting and sharing research on severity and tractability, crafting comprehensive strategies and conducting advocacy. These network activities exerted indirect influence leading to increased attention, funding, policies and some implementation.

A critical time for rotavirus vaccines: a review

Universal introduction of rotavirus vaccines into childhood immunization programs is expected to substantially reduce the mortality from rotavirus gastroenteritis in developing countries (currently estimated at 702,000 annual deaths among children less than 5 years of age). In addition, it is expected to virtually eliminate hospitalizations due to rotavirus gastroenteritis in developed countries. Two rotavirus vaccines, Rotarix (GlaxoSmithKline Biologicals, Belgium) and RotaTeq (Merck & Co., USA) have recently completed Phase III clinical trials, each involving more than 60,000 children. Both vaccines appear safe with respect to intussusception, and are highly efficacious in preventing severe gastroenteritis due to rotavirus strains carrying predominantly serotype G1. The monovalent human rotavirus vaccine Rotarix, possessing serotype P1A[8],G1, is being first introduced into developing countries, whereas the pentavalent bovine-human reassortant rotavirus vaccine RotaTeq, comprising G-types G1, G2, G3, G4 and P-type P1A[8], will be initially introduced into the USA and Europe. Current disease burden estimates and economic justification will be required wherever the vaccines are introduced. Confirmation of the safety of both vaccines will require extensive postlicensure evaluation in which it will be key to assure adherence to administration of the first dose of either vaccine before 3 months of age. Assessment of the ability of each vaccine to provide protection against an increasingly diverse population of rotavirus strains will crucially depend on continuous global strain surveillance. Finally, efforts to improve existing rotavirus vaccines and to develop alternative vaccines should continue, so as to ensure that the prerotavirus vaccine era is consigned to a historical context.

Too much of a good thing? When to stop catch-up vaccination

During the 20th century, deaths from a range of serious infectious diseases decreased dramatically due to the development of safe and effective vaccines. However, infant immunization coverage has increased only marginally since the 1960s, and many people remain susceptible to vaccine-preventable diseases. "Catch-up vaccination" for age groups beyond infancy can be an attractive and effective means of immunizing people who were missed earlier. However, as newborn vaccination rates increase, catch-up vaccination becomes less attractive: the number of susceptible people decreases, so the cost to find and vaccinate each unvaccinated person may increase; in addition, the number of infected individuals decreases, so each unvaccinated person faces a lower risk of infection. This article presents a general framework for determining the optimal time to discontinue a catch-up vaccination program. We use a cost-effectiveness framework: we consider the cost per quality-adjusted life year gained of catch-up vaccination efforts as a function of newborn immunization rates over time and consequent disease prevalence and incidence. We illustrate our results with the example of hepatitis B catch-up vaccination in China. We contrast results from a dynamic modeling approach with an approach that ignores the impact of vaccination on future disease incidence. The latter approach is likely to be simpler for decision makers to understand and implement because of lower data requirements.

Role of radiofrequency ablation in unresectable hepatocellular carcinoma: An Indian experience

AIMS

To evaluate the role of radiofrequency ablation (RFA) as an ablative technique in patients with unresectable hepatocellular carcinoma (HCC).

SETTINGS AND DESIGN

A tertiary care center, prospective study.

MATERIALS AND METHODS

The subjects comprised 31 patients (30 males, one female; age range 32-75 years) with HCC (41 lesions) who were treated with image-guided RFA. The follow-up period ranged from 3 months to 6 years, and included a multiphasic computed tomography (CT) at 1, 3 and 6 months post-RFA, and every 6 months thereafter. Patient outcome was evaluated and the tumor recurrence, survival and complications were assessed.

STATISTICAL ANALYSIS USED

Discrete categorical data were presented as n (%) and continuous data as mean ± SD. Pearson correlation coefficient was used to determine the relationship between the different variables. Kaplan-Meier survival curve and Log-rank test were used to test the significance of difference between the survival time of the different groups.

RESULTS

The ablation success rate was 80.5% (33/41 HCC lesions). 12.2% (5/41) of the lesions were managed with repeat RFA due to tumor residue. 4.9% (2/41) of the lesions were managed with repeated RFA and transarterial chemoembolization. Eight patients had tumor recurrence (five patients (16.1%) had local recurrence and three patients (9.6%) had distant recurrence). Eleven patients died within 3.5-20 months post-RFA. The survival rate at 1 year in patients who completed at least 1 year of follow-up was 63.3%. There was one major complication (1/31, 3.2%) in a patient with a subcapsular lesion and ascites. This patient developed hemoperitoneum in the immediate postprocedure period and was managed with endovascular treatment. She, however, had hepatic decompensation and died 48 h post-RFA.

CONCLUSION

RFA is an effective and safe treatment for small unresectable HCC.

Introducing multiple vaccines in low- and lower-middle-income countries: issues, opportunities and challenges

Low- and lower-middle-income countries are faced with a large and increasingly complicated portfolio of vaccines to introduce into their national immunization programmes. Countries must also incorporate their vaccine introduction plans into donor-required assessments and multi-year plans. An international workshop and series of key informant interviews were conducted to explore the interest, opportunities and challenges for the proactive planning of multiple vaccine introduction within a single planning cycle and the underlying processes for planning the introduction of new vaccines. The study found limited experience with this proactive planning process in low-income countries and used the experience of two lower-middle-income countries in simultaneously introducing rotavirus and pneumococcal vaccines to highlight the importance of integrating the planning processes for new vaccine introduction into broader immunization systems planning and financing. The study's findings suggest that this strategy for vaccine introduction may have promise for accelerating the pace of new vaccine introduction. However, we also show that realizing these benefits will require improved logistic and financial planning activities and continued actions to resolve uncertainties in the relationships between donors, technical agencies, and the national immunization programmes.

Implementing new health interventions in developing countries: why do we lose a decade or more?

BACKGROUND

It is unclear how long it takes for health interventions to transition from research and development (R&D) to being used against diseases prevalent in resource-poor countries. We undertook an analysis of the time required to begin implementation of four vaccines and three malaria interventions. We evaluated five milestones for each intervention, and assessed if the milestones were associated with beginning implementation.

METHODS

The authors screened World Health Organization (WHO) databases to determine the number of years between first regulatory approval of interventions, and countries beginning implementation. Descriptive analyses of temporal patterns and statistical analyses using logistic regression and Cox proportional hazard models were used to evaluate associations between five milestones and the beginning of implementation for each intervention. The milestones were: (A) presence of a coordinating group focused on the intervention; (B) availability of an intervention tailored to developing country health systems; (C) international financing commitment, and; (D) initial and (E) comprehensive WHO recommendations. Countries were categorized by World Bank income criteria.

RESULTS

Five years after regulatory approval, no low-income countries (LICs) had begun implementing any of the vaccines, increasing to an average of only 4% of LICs after 10 years. Each malaria intervention was used by an average of 7% of LICs after five years and 37% after 10 years. Four of the interventions had similar implementation rates to hepatitis B vaccine (HepB), while one was slower and one was faster than HepB. A financing commitment and initial WHO recommendation appeared to be temporally associated with the beginning of implementation. The initial recommendation from WHO was the only milestone associated in all statistical analyses with countries beginning implementation (relative rate = 1.97, P < 0.001).

CONCLUSIONS

Although possible that four milestones were not associated with countries beginning implementation, we propose an alternative interpretation; that the milestones were not realized early enough in each intervention's development to shorten the time to beginning implementation. We discuss a framework built upon existing literature for consideration during the development of future interventions. Identifying critical milestones and their timing relative to R&D, promises to help new interventions realize their intended public health impact more rapidly.

Increased prevalence of rotavirus among children associated gastroenteritis in Riyadh Saudi Arabia

The aim of this study is to assess the epidemiology along with the molecular structure of rotavirus causing pediatric diarrhea among Saudi patients. However, in this report we sited the epidemiological reflect coming from our project.

Cost-effectiveness of rotavirus vaccination in Bolivia from the state perspective

BACKGROUND

In Bolivia, in 2008, the under-five mortality rate is 54 per 1000 live births. Diarrhea causes 15% of these deaths, and 40% of pediatric diarrhea-related hospitalizations are caused by rotavirus illness (RI). Rotavirus vaccination (RV), subsidized by international donors, is expected to reduce morbidity, mortality, and economic burden to the Bolivian state. Estimates of illness and economic burden of RI and their reduction by RV are essential to the Bolivian state's policies on RV program financing. The goal of this report is to estimate the economic burden of RI and the cost-effectiveness of the RV program.

METHODS

To assess treatment costs incurred by the healthcare system, we abstracted medical records from 287 inpatients and 6751 outpatients with acute diarrhea between 2005 and 2006 at 5 sentinel hospitals in 4 geographic regions. RI prevalence rates were estimated from 4 years of national hospital surveillance. We used a decision-analytic model to assess the potential cost-effectiveness of universal RV in Bolivia.

RESULTS

Our model estimates that, in a 5-year birth cohort, Bolivia will incur over US$3 million in direct medical costs due to RI. RV reduces, by at least 60%, outpatient visits, hospitalizations, deaths, and total direct medical costs associated with rotavirus diarrhea. Further, RV was cost-savings below a price of US$3.81 per dose and cost-effective below a price of US$194.10 per dose. Diarrheal mortality and hospitalization inputs were the most important drivers of rotavirus vaccine cost-effectiveness.

DISCUSSION

Our data will guide Bolivia's funding allocation for RV as international subsidies change.

The continuing role of Haemophilus influenzae type b carriage surveillance as a mechanism for early detection of invasive disease activity

Prior to the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines, Hib was the leading cause of bacterial meningitis in children under five years of age worldwide. In countries that have adopted Hib vaccination schedules, invasive disease has reduced markedly. Oro-naso pharyngeal carriage is recognized as the most significant source of infection. Hib carriage is significantly associated with poverty, such as overcrowding, poor ventilation in houses, lack of running water, and high smoking rates. Additionally, many Indigenous minority groups report high rates of Hib carriage. A resurgence of Hib disease among Alaskan children in the 1990s, lead to a change in approach to eliminate Hib disease and carriage in high-risk populations. This new approach identifies strategies for eliminating Hib disease focusing on the reservoirs of colonization within families and communities. Monitoring Hib carriage continues to offer an early warning system, whereby intervention could prevent invasive disease resurgence.

Cost analysis of care for children admitted to kenyatta national hospital with rotavirus gastroenteritis

Rotavirus infection is the single most common cause of acute gastroenteritis in children under five years of age. The costs of care and treatment for rotavirus gastroenteritis are high. The objective was to compute average cost of care for children admitted with rotavirus gastroenteritis. A survey was conducted in children admitted with a diagnosis of acute gastroenteritis in Nairobi, Kenya. These were recruited and followed up till discharge or death. The costs they incurred were collected and the average costs were calculated. We concluded that rotavirus gastroenteritis leads to considerable resource utilization in health care settings and the society.

Economic evaluation of pneumococcal conjugate vaccination in The Gambia

BACKGROUND

Gambia is the second GAVI support-eligible country to introduce the 7-valent pneumococcal conjugate vaccine (PCV7), but a country-specific cost-effectiveness analysis of the vaccine is not available. Our objective was to assess the potential impact of PCVs of different valences in The Gambia.

METHODS

We synthesized the best available epidemiological and cost data using a state-transition model to simulate the natural histories of various pneumococcal diseases. For the base-case, we estimated incremental cost (in 2005 US dollars) per disability-adjusted life year (DALY) averted under routine vaccination using PCV9 compared to no vaccination. We extended the base-case results for PCV9 to estimate the cost-effectiveness of PCV7, PCV10, and PCV13, each compared to no vaccination. To explore parameter uncertainty, we performed both deterministic and probabilistic sensitivity analyses. We also explored the impact of vaccine efficacy waning, herd immunity, and serotype replacement, as a part of the uncertainty analyses, by assuming alternative scenarios and extrapolating empirical results from different settings.

RESULTS

Assuming 90% coverage, a program using a 9-valent PCV (PCV9) would prevent approximately 630 hospitalizations, 40 deaths, and 1000 DALYs, over the first 5 years of life of a birth cohort. Under base-case assumptions ($3.5 per vaccine), compared to no intervention, a PCV9 vaccination program would cost $670 per DALY averted in The Gambia. The corresponding values for PCV7, PCV10, and PCV13 were $910, $670, and $570 per DALY averted, respectively. Sensitivity analyses that explored the implications of the uncertain key parameters showed that model outcomes were most sensitive to vaccine price per dose, discount rate, case-fatality rate of primary endpoint pneumonia, and vaccine efficacy against primary endpoint pneumonia.

CONCLUSIONS

Based on the information available now, infant PCV vaccination would be expected to reduce pneumococcal diseases caused by S. pneumoniae in The Gambia. Assuming a cost-effectiveness threshold of three times GDP per capita, all PCVs examined would be cost-effective at the tentative Advance Market Commitment (AMC) price of $3.5 per dose. Because the cost-effectiveness of a PCV program could be affected by potential serotype replacement or herd immunity effects that may not be known until after a large scale introduction, type-specific surveillance and iterative evaluation will be critical.

Rotavirus infections among HIV-infected children in Nairobi, Kenya

Human rotaviruses have emerged as a leading cause of acute diarrhea in children <5 years of age worldwide. Although there are previous reports relating to various aspects of rotaviruses, there is limited data on the involvement of rotavirus infection in HIV-infected children. We therefore evaluated the importance of rotavirus infections in HIV-related diarrhea in Kenyan children. Fecal samples were collected from a total of 207 children during the period February 1999 to June 2000 and screened for HRV antigen by enzyme-linked immunosorbent assay (ELISA). Positive samples were analyzed by VP6 subgroup specificity assay, by polyacrylamide gel electrophoresis (PAGE) and reverse transcriptase/polymerase chain reaction (RT-PCR). Fourteen percent (29/207) of the samples were positive. HIV-seropositive children with diarrhea were more likely than their counterparts without diarrhea to have rotaviruses [23.3% (10/43) versus 2.9% (2/70); p = 0.0001]. Rotavirus strain G3P[6] was predominant. These results indicate that rotavirus is an important viral etiological agent causing diarrhea in HIV-seropositive children.

Reviewing the cost effectiveness of rotavirus vaccination: the importance of uncertainty in the choice of data sources

Published health economic evaluations of rotavirus vaccination up until July 2008 were reviewed. We assess whether differences in the results and conclusions of the various studies are due to differences in methodological and modelling choices, and/or the way parameter uncertainty was taken into account, or whether these are merely the result of genuine country/region-specific differences. No unambiguous single answer emerged as to whether universal rotavirus vaccination is or is not cost effective. The relevance and merits of each study need to be assessed within its context. This is illustrated by the fact that comparisons of different analyses for a single country show that one of the most important explanations for the variations in results and conclusions seems to be the use of different information sources for the estimation of input parameters. Future studies should gather reliable and relevant information focusing on the most influential input parameters, i.e. rotavirus mortality (and efficacy against rotavirus deaths) for low- and middle-income countries, and a range of variables for high-income countries, including the incidence and cost of rotavirus hospitalization. Moreover, if no information is available for an important input parameter, the impact of a wide range of values should be explored rather than excluding it from the analysis or specifying a single-point value. Furthermore, future analyses may have to consider ways of accounting for herd immunity (e.g. by using a dynamic model).

Development of vaccine risk communication messages using risk comparisons and mathematical modeling

It is important to systematically assess the vaccine information needs of parents in order to maintain or improve childhood immunization coverage. Our objectives were to obtain suggestions for the optimal presentation of vaccine-related information and to determine if an educational intervention affected mothers' vaccine safety attitudes. Focus groups were used to develop messages that then were tested through a randomized, pre- and post-test mail survey of non-Hispanic White mothers who reported vaccine safety concerns (n = 927). Focus groups were analyzed using text analysis software. Increases in attitude scores between the pre- and post-test surveys were calculated, and logistic regression was used to compare intervention groups with a control group. Of survey participants who recalled the test messages, 50% (85/171) who received a "consequences of reduced coverage" message reported an improved opinion of vaccines. A greater proportion of participants receiving one or more intervention messages reported an improved attitude score from pre-to post-test compared with the control group for four of the five variables measured; however, differences were small and none were statistically significant. A mixed method approach was used to develop and test vaccine messages. The message describing potential consequences of reduced vaccination coverage had the greatest impact on improving concerned mothers' opinions of childhood vaccines.

Vaccines to prevent pneumonia and improve child survival

For more than 30 years, vaccines have played an important part in pneumonia prevention. Recent advances have created opportunities for further improving child survival through prevention of childhood pneumonia by vaccination. Maximizing routine immunization with pertussis and measles vaccines, coupled with provision of a second opportunity for measles immunization, has rapidly reduced childhood deaths in low-income countries especially in sub-Saharan Africa. Vaccines against the two leading bacterial causes of child pneumonia deaths, Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (pneumococcus), can further improve child survival by preventing about 1,075,000 child deaths per year. Both Hib and pneumococcal conjugate vaccines have proven safety and effectiveness for prevention of radiologically confirmed pneumonia in children, including in low-income and industrializing countries. Both are recommended by WHO for inclusion in national programmes, and, at sharply tiered prices, these vaccines generally meet international criteria of cost-effectiveness for low-income countries. Vaccines only target selected pneumonia pathogens and are less than 100% effective, so they must be complemented by curative care and other preventative strategies. As part of a comprehensive child survival package, the particular advantages of vaccines include the ability to reach a high proportion of all children, including those who are difficult to reach with curative health services, and the ability to rapidly scale up coverage with new vaccines. In this review, we discuss advances made in optimizing the use of established vaccines and the potential issues related to newer bacterial conjugate vaccines in reducing childhood pneumonia morbidity and mortality.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Economic evaluation of hepatitis B vaccination in low-income countries: using cost-effectiveness affordability curves

OBJECTIVE

We sought to describe a method that explicitly considers both a health-care programmes cost-effectiveness and its affordability. For illustration, we apply the method to the programme to vaccinate infants against hepatitis B in the Gambia.

METHODS

We synthesized selected data and developed a computer-based model from the societal and payer perspectives to evaluate the cost-effectiveness of routine infant vaccination against hepatitis B in the Gambia compared with no vaccination. The primary outcome measure was cost per averted disability-adjusted life year (DALY), which was expressed in 2002 US dollars. We used Monte Carlo methods for uncertainty analysis to examine the affordability of the programme from the payers perspective, and we derived an affordability curve and cost-effectiveness affordability curves for the programme.

FINDINGS

In the Gambia, vaccinating infants against hepatitis B is highly cost-effective. Compared with offering no intervention, the vaccination programme would cost US$ 28 per DALY averted from the societal perspective or US$ 47 per DALY averted from the payers perspective. The programme also has the potential to be affordable, starting at a relatively low budget of US$ 160,000 per year. Combining the two dimensions of the outcome measure, the probability that vaccinating infants would be both cost-effective and affordable is 40% at an annual programme budget of US$ 182,000 (the estimated total programme cost from the payers perspective), given a threshold cost-effectiveness value of US$ 47 per DALY averted.

CONCLUSION

In the face of uncertainties about both the health and economic consequences of a vaccine programme, as well as the availability and magnitude of resources needed to fund the programme, cost-effectiveness affordability curves can provide information to decision-makers about the probability that a programme will be both cost-effective and affordable: these are distinct but equally relevant considerations in resource-poor settings.

Deaths from rotavirus disease in Bangladeshi children: estimates from hospital-based surveillance

BACKGROUND

To assess the potential health benefits of introducing new rotavirus (RV) vaccines, we estimated mortality from RV gastroenteritis in Bangladeshi children <5 years of age.

METHODS

We examined data from ongoing diarrhea surveillance in a systematic 2% sample (4% until 1995) of patients visiting the International Centre for Diarrheal Disease Research, Bangladesh, Dhaka Hospital during 1993-2004 and all patients visiting the rural Matlab Hospital during 2000-2004. To estimate deaths from RV, we multiplied the proportion of diarrhea visits attributable to RV with 2004 estimates of diarrhea deaths in Bangladeshi children.

RESULTS

At Dhaka Hospital, RV was detected in 33% of 18,300 children with diarrhea. The proportion of diarrhea attributable to RV nearly doubled during 2002-2004 compared with 1993-1995 (42% versus 22%, P < 0.001). At Matlab Hospital, RV was detected in 35% of 4597 children with diarrhea. At both sites, most RV cases were among children age 3-24 months and the number of cases peaked during the cool and dry months from December through February. Of the 325,600 deaths among children <5 years that occur each year, we estimated 5600 to 9400 (2-3%) were attributable to RV. Thus, between 1 in 390 and 1 in 660 children born in Bangladesh each year die of RV infection by age 5.

CONCLUSIONS

These data clearly demonstrate the tremendous health burden of RV gastroenteritis. The increasing proportion of severe diarrhea cases underscores the need for specific interventions against RV, such as vaccines, to further reduce diarrhea mortality and morbidity.

The evidence for using conjugate vaccines to protect HIV-infected children against pneumococcal disease

Pneumococcal conjugate vaccines (PCVs) are a potentially useful complement to existing treatment strategies in HIV-infected children, for whom pneumococcal infections are common and serious. This Review summarises available data on the burden of pneumococcal disease and the safety and efficacy of PCVs in HIV-infected children. The data demonstrate that children with HIV have significantly increased risk of pneumococcal disease compared with uninfected children; the serotypes included in currently licensed or near-licensure conjugate vaccines include most serotypes that cause invasive pneumococcal disease (IPD) in HIV-infected children and adults; PCVs provide substantial protection against IPD and clinical pneumonia when given to HIV-infected infants; and HIV-infected adults gain an indirect benefit when children in the community are vaccinated. PCV should be considered as an important intervention for improving the lives of HIV-infected children.

Should hepatitis B vaccine be used for infants?

Chronic hepatitis B virus infection causes nearly all the deaths from this virus. As the initial infection occurs without symptoms and decades prior to the onset of cirrhosis and liver cancer, these consequences are rarely recognized as being caused by the virus. Consequently, its public health importance is under-recognized. Safe and effective vaccines have now been available for over 20 years. Concerns have been raised regarding the mercury preservative in vaccines leading to potential toxicity. But the evidence to date does not support any association of hepatitis B vaccine with serious adverse consequences. Protecting infants through immunization is the most effective control strategy. By 2005, over 80% of countries had implemented routine infant immunization. In countries with relatively low rates of hepatitis B virus infection, some have argued to defer immunization until later life. However, these arguments focus on the more visible acute infection. The possible future cost from a single infant infection argues for universal infant hepatitis B immunization--given the very high costs of treating its consequences (e.g., liver transplant) and the very low price of the vaccine.

Cost-effectiveness of pneumococcal conjugate vaccination in the prevention of child mortality: an international economic analysis

BACKGROUND

Routine vaccination of infants against Streptococcus pneumoniae (pneumococcus) needs substantial investment by governments and charitable organisations. Policymakers need information about the projected health benefits, costs, and cost-effectiveness of vaccination when considering these investments. Our aim was to incorporate these data into an economic analysis of pneumococcal vaccination of infants in countries eligible for financial support from the Global Alliance for Vaccines & Immunization (GAVI).

METHODS

We constructed a decision analysis model to compare pneumococcal vaccination of infants aged 6, 10, and 14 weeks with no vaccination in the 72 countries that were eligible as of 2005. We used published and unpublished data to estimate child mortality, effectiveness of pneumococcal conjugate vaccine, and immunisation rates.

FINDINGS

Pneumococcal vaccination at the rate of diptheria-tetanus-pertussis vaccine coverage was projected to prevent 262,000 deaths per year (7%) in children aged 3-29 months in the 72 developing countries studied, thus averting 8.34 million disability-adjusted life years (DALYs) yearly. If every child could be reached, up to 407,000 deaths per year would be prevented. At a vaccine cost of International 5 dollars per dose, vaccination would have a net cost of 838 million dollars, a cost of 100 dollars per DALY averted. Vaccination at this price was projected to be highly cost-effective in 68 of 72 countries when each country's per head gross domestic product per DALY averted was used as a benchmark.

INTERPRETATION

At a vaccine cost of between 1 dollar and 5 dollars per dose, purchase and accelerated uptake of pneumococcal vaccine in the world's poorest countries is projected to substantially reduce childhood mortality and to be highly cost-effective.

Time preferences for health in northern Tanzania: an empirical analysis of alternative discounting models

AIM

The discounted utility (DU) model has dominated economic evaluation for almost 7 decades, despite the fact that important assumptions of the model are commonly found to be violated. This paper formally explores whether the key assumption of stationarity is violated in a sample of the general population of Northern Tanzania. Furthermore, three hyperbolic discounting models are fitted to the data, and whether they perform better than the DU model in predicting individuals' time preferences is tested using nonlinear least squares regression.

METHOD

The data were collected from 450 households by trained enumerators. The individual data on time preferences were collected by structured interviews using an open-ended stated preference methodology. Respondents marked a rating scale to indicate the maximum number of days they would be willing to suffer a nonfatal disease if the outbreak of the disease could be delayed to a point further into the future. Households were randomised to answer questions framed to elicit either a private or social time preference.

RESULTS

Hypothesis testing confirmed decreasing time aversion and a magnitude effect, suggesting that the DU model is inappropriate as a descriptive tool. When the DU model was compared with the three hyperbolic discounting models by analysing the discount factor using nonlinear least squares regression, the most important findings were that a variable for starting point was nonsignificant only for the Loewenstein and Prelec (L&P) and the Mazur models, and that people in this setting generally discounted future health far more than suggested by current discounting practice in economic evaluations.

CONCLUSION

The time preferences of our sample are better represented by the L&P and the Mazur models (which allow relaxation of the stationarity assumption through a modification of the expression for the discount factor) and less well reflected by the Harvey (a modification of the L&P model that assigns more importance to the future than standard utility discounting) and DU models. This implies that, from the point of view of a consumer sovereignty-friendly economist, the Mazur and the L&P models are preferable for discounting of future health in economic evaluations. However, from the point of view of other value bases for discounting the choice of discounting model is of less importance.

Rotavirus disease in Uzbekistan: Cost-effectiveness of a new vaccine

We evaluated the cost-effectiveness of rotavirus vaccination in Uzbekistan from the healthcare system and societal perspectives. Disease burden was estimated using national statistics on hospitalizations and deaths, and international estimates of under-five mortality. Without vaccination, the risk for rotavirus hospitalization by age 5 is 10 per 1000 children. Rotavirus hospitalizations cost US$ 406,000 annually, of which US$ 360,000 (89%) is for medical expenses and US$ 46,000 (11%) is for non-medical and indirect costs. Rotavirus mortality rate at 0.7 per 1000 derived from national data was three-fold lower than the same rate calculated from international estimates of under-five mortality. Rotavirus vaccination could reduce hospitalizations and deaths by 91% and avert US$ 370,000 in hospitalization costs alone. Vaccination would be cost-effective with vaccine prices in a range of US$ 2-25 per child. However, the cost-effectiveness is greatly influenced by mortality, vaccine price and vaccine efficacy.

Disease burden and related medical costs of rotavirus infections in Taiwan

Background

The disease burden and associated medical costs of rotavirus infections in inpatient and outpatient sectors in Taiwan were examined in anticipation of the availability of new rotavirus vaccines.

Methods

The yearly national case number and medical costs for all for inpatients and outpatients with acute gastroenteritis (AGE) were extracted from the Bureau of National Health Insurance database in Taiwan according to ICD-9-CM codes. A retrospective study was also performed using records of children with AGE seen at three hospitals in Taiwan in 2001 to identify laboratory confirmed rotavirus infection cases. The annual incidence and related medical costs of AGE due to rotavirus infection were then estimated.

Results

Children <5 years old comprised 83.6% of inpatient and 62.0% of outpatient pediatric AGE cases in Taiwan in 2001. Rotavirus was the most common agent detected among AGE patients in this age group in the three hospitals, and was detected in 32.9% (221/672) of inpatient and 24% (23/96) of outpatient stool specimens tested for microbial etiologies. An estimated 277,400 to 624,892 cases of rotavirus infections sought medical care in Taiwan in 2001, equaling one in 2 to 5 children <5 years old required medical care due to rotavirus infection. The incidence of hospitalization due to rotavirus infections was 1,528–1,997/100,000 for children <5 years old. The total associated medical costs due to rotavirus infection were estimated at US $10–16 millions in Taiwan in 2001. Although the per-capita medical cost of rotavirus infection was lower in Taiwan than in the United States or Hong Kong, the personal economic burden was similar among the three places when normalized for gross national incomes per capita.

Conclusion

Infections caused by rotavirus constitute an important human and economic burden among young children in Taiwan. A safe and effective vaccine is urgently needed.

The cost of treatment for child pneumonias and meningitis in the Northern Areas of Pakistan

Pneumonia, meningitis, and sepsis place a significant economic burden on health care systems, particularly in developing countries. This study estimates treatment costs for these diseases in health facilities in the Northern Areas of Pakistan. Health facility resources are organized by categories--including salaries, capital costs, utilities, overhead, maintenance and supplies--and quantified using activity-based costing (ABC) techniques. The average cost of treatment for an outpatient case of child pneumonia is dollar 13.44. For hospitalized care, the health system spent an average of dollar 71 per episode for pneumonia, dollar 235 for severe pneumonia, and dollar 2,043 for meningitis. These costs provide important background information for the potential introduction of the conjugate Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae vaccines in Pakistan.

Tandem copies of a human rotavirus VP8 epitope can induce specific neutralizing antibodies in BALB/c mice

The VP8 subunit protein of human rotavirus (HRV) plays an important role in viral infectivity and neutralization. Recombinant peptide antigens displaying the amino acid sequence M(1)ASLIYRQLL(10), a linear neutralization epitope on the VP8 protein, were constructed and examined for their ability to generate anti-peptide antibodies and HRV-neutralizing antibodies in BALB/c mice. Peptide antigen constructs were expressed in E. coli as fusion proteins with thioredoxin and a universal tetanus toxin T-cell epitope (P2), in order to enhance the anti-peptide immune response. The peptide antigen containing three tandem copies of the VP8 epitope induced significantly higher levels of anti-peptide antibody than only a single copy of the epitope, or the peptide co-administered with the carrier protein and T-cell epitope. Furthermore, the peptide antigen containing three copies of the peptide produced significantly higher virus-neutralization titres, higher than VP8, indicating that a peptide antigen displaying repeating copies of the amino acid region 1-10 of VP8 is a more potent inducer of HRV-neutralizing antibodies than VP8 alone, and may be useful for the production of specific neutralizing antibodies for passive immunotherapy of HRV infection.

Progress towards the development of malaria vaccines

The misery and suffering caused worldwide by infection with the malaria parasite, especially Plasmodium falciparum, has been well documented. Although no licensed vaccine against malaria currently exists, progress has accelerated in recent years towards the goal of developing one. Although the complexity of the malaria parasite has made the malaria vaccine development process tenuous, advances in science and in the vaccine development process as well as increases in funding are encouraging. These advances, coupled with the results of the recent clinical trial of the vaccine candidate RTS,S, have added new vigor to the idea that a malaria vaccine is not only possible but probable.

Rotavirus infection in Saudi Arabia

BACKGROUND

Human rotavirus, an important causative agent of severe gastroenteritis in infants and young children worldwide, leads to high morbidity in both developing and developed countries, including Saudi Arabia, and high mortality in developing countries. Effective control depends upon an accurate understanding of disease burden and the relative importance of circulating serotypes.

METHODS

We examined the epidemiology and disease burden of rotavirus in Saudi Arabia through a review of 22 published studies of rotavirus and the aetiology of diarrhoea carried out from 1982 to 2003.

RESULTS

The prevalence of rotavirus infection ranged between 10% to 46% with a median of 30%. Most cases were among children less than 2 years of age, and particularly in the first year of life. There were significant differences in seasonality within Saudi Arabia, with increased infection during winter in some cities and during summer in others. G1 was the predominant serotype followed by G4, G3 and G2, in 4 studies where strains had been G-typed. The prevalence of nontypeable strains ranged from 11.0% to 31.3%. No data were available on P types. Results of electropherotyping in 4 studies revealed that the long electropherotype was predominant.

CONCLUSION

Rotavirus is an important cause of severe diarrhoea in Saudi children. However, the available data on rotavirus strains in circulation are limited and there is an urgent need for up-to-date and comprehensive studies to evaluate rotavirus strains in circulation and identify unusual types that could be incorporated into future vaccines.

Should universal hepatitis B immunisation be introduced in the UK?

Yes. But how?

Serotype diversity and reassortment between human and animal rotavirus strains: implications for rotavirus vaccine programs

The development of rotavirus vaccines that are based on heterotypic or serotype-specific immunity has prompted many countries to establish programs to assess the disease burden associated with rotavirus infection and the distribution of rotavirus strains. Strain surveillance helps to determine whether the most prevalent local strains are likely to be covered by the serotype antigens found in current vaccines. After introduction of a vaccine, this surveillance could detect which strains might not be covered by the vaccine. Almost 2 decades ago, studies demonstrated that 4 globally common rotavirus serotypes (G1-G4) represent >90% of the rotavirus strains in circulation. Subsequently, these 4 serotypes were used in the development of reassortant vaccines predicated on serotype-specific immunity. More recently, the application of reverse-transcription polymerase chain reaction genotyping, nucleotide sequencing, and antigenic characterization methods has confirmed the importance of the 4 globally common types, but a much greater strain diversity has also been identified (we now recognize strains with at least 42 P-G combinations). These studies also identified globally (G9) or regionally (G5, G8, and P2A[6]) common serotype antigens not covered by the reassortant vaccines that have undergone efficacy trials. The enormous diversity and capacity of human rotaviruses for change suggest that rotavirus vaccines must provide good heterotypic protection to be optimally effective.

Rotavirus serotypes and electropherotypes identified among hospitalised children in São Luís, Maranhão, Brazil

During June 1997-June 1999 rotavirus infection was screened in infants aged up to 2 years and hospitalised with acute diarrhoea in São Luís, Northeastern Brazil. Altogether, 128 stool samples were collected from diarrhoeic patients and additional 122 faecal specimens from age- and- temporal matched inpatients without diarrhoea were obtained; rotavirus positivity rates for these groups were 32.0% (41/128) and 9.8% (12/122), respectively (p < 0.001). Both electropherotyping and serotyping could be performed in 42 (79.2%) of the 53 rotavirus-positive stool samples. Long and short electropherotypes were detected at similar rates - 38.1% and 40.5% of specimens, respectively. Overall, a G serotype could be assigned for 35 (83.3%) of specimens, the majority of them (66.7%) bearing G1-serotype specificity. Taking both electropherotypes and serotypes together, G1 rotavirus strains displaying long and short RNA patterns accounted for 30.9% and 19.0% of tested specimens, respectively; all G2 strains had short electropherotype. Rotavirus gastroenteritis was detected year-round and, in 1998, the incidence rates tended to be higher during the second semester than in the first semester: 45.2% and 26.1% (p = 0.13), respectively. Rotavirus infections peaked at the second semester of life with frequencies of 30.1% and 13.5% for diarrhoeic children and controls, respectively. While the six rotavirus strains bearing G2-type specificity were circulating throughout the whole study period, G1 serotypes (n = 27) emerged as from June 1998 onwards, 20 (74.1%) of which clustering in 1998. These data underscore the importance of rotaviruses in the aetiology of severe infantile gastroenteritis in Northeastern Brazil and sustain the concept that a future vaccine should confer protection against more than one serotype.