H.A.T. Tu

Comparative review of three cost-effectiveness models for rotavirus vaccines in national immunization programs; a generic approach applied to various regions in the world

BackgroundThis study aims to critically review available cost-effectiveness models for rotavirus vaccination, compare their designs using a standardized approach and compare similarities and differences in cost-effectiveness outcomes using a uniform set of input parameters.MethodsWe identified various models used to estimate the cost-effectiveness of rotavirus vaccination. From these, results using a standardized dataset for four regions in the world could be obtained for three specific applications.ResultsDespite differences in the approaches and individual constituting elements including costs, QALYs Quality Adjusted Life Years and deaths, cost-effectiveness results of the models were quite similar. Differences between the models on the individual components of cost-effectiveness could be related to some specific features of the respective models. Sensitivity analysis revealed that cost-effectiveness of rotavirus vaccination is highly sensitive to vaccine prices, rotavirus-associated mortality and discount rates, in particular that for QALYs.ConclusionsThe comparative approach followed here is helpful in understanding the various models selected and will thus benefit (low-income) countries in designing their own cost-effectiveness analyses using new or adapted existing models. Potential users of the models in low and middle income countries need to consider results from existing studies and reviews. There will be a need for contextualization including the use of country specific data inputs. However, given that the underlying biological and epidemiological mechanisms do not change between countries, users are likely to be able to adapt existing model designs rather than developing completely new approaches. Also, the communication established between the individual researchers involved in the three models is helpful in the further development of these individual models. Therefore, we recommend that this kind of comparative study be extended to other areas of vaccination and even other infectious disease interventions.

Economic evaluations of rotavirus immunization for developing countries: a review of the literature

Diarrhea is a leading cause of mortality for children under 5 years of age, and rotavirus is identified as the main cause of severe diarrhea worldwide. Since 2006, two rotavirus vaccines, Rotarix and Rotateq, have been available in the market. These vaccines have proved to have high efficacy in developed countries. Clinical trials are being undertaken in Asia and Africa, and early clinical results found that the vaccine significantly reduces severe diarrhea episodes due to rotavirus (48.3% for Asia and 30.2% for Africa). The WHO recommended that rotavirus immunization be included in all national immunization programs. Based on WHO’s recommendations, the Global Alliance for Vaccines and Immunization decided to provide financial support for rotavirus immunization in the developing world. In this article, we attempted to ascertain the cost–effectiveness of universal rotavirus immunization in developing countries. After an extensive literature search, we identified and evaluated 15 cost–effectiveness studies conducted in the developing world. The results from these studies showed that rotavirus immunization is a cost-effective strategy and one of the best interventions to prevent rotavirus-related diarrheal disease. However, rotavirus vaccines are expensive and the vaccine price appears to be the most challenging and crucial factor for decision-makers regarding whether to introduce this vaccine into developing countries’ immunization schedules. All the studies concluded that rotavirus immunization is cost effective but may not be affordable for the developing world at present. Developing countries will definitely rely on financial support from international organizations to introduce rotavirus vaccination. It is recommended that more research on cost-effective rotavirus immunization with updated data be conducted and new rotavirus vaccine candidates be developed at a cheaper price to speed up the introduction of rotavirus immunization to the developing world.

Economic evaluations of hepatitis B vaccination for developing countries

Economic evaluations, in particular cost–effectiveness, are important determinants for policy makers and stakeholders involved in decision-making for health interventions. Up until now, most evaluations of cost–effectiveness of hepatitis B vaccination have been performed in developed countries. Appropriate health–economic studies on this topic specifically targeted at the developing world are essential in order to justify adding another vaccine into the existing Expanded Program on Immunization in these countries. We present a systematic review of economic evaluations of vaccination against HBV for developing and less-developed countries. Vaccine price, the discount rate, incidence and prevalence of HBV infection were found to be major drivers of cost–effectiveness. Data accuracy and reliability were also major issues, with major potentials for improvement in studies of these countries. The choice between monovalent or combination vaccines (diphteria, tetanus and polio–hepatitis B) poses new challenges to cost–effectiveness analysis. It is concluded that for many developing countries implementation of universal immunization against HBV to reduce the level of endemicity of hepatitis B is an appropriate strategy, and probably cost effective in many settings. Given their limited financial resources, developing countries should properly plan how to achieve this. Further country-specific economic evaluations and related gathering of high-quality data must be conducted in developing countries in order to raise both public awareness of the effectiveness and economic attractiveness of universal immunization against HBV.

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.

A review of the literature on the economics of vaccination against TB

The BCG vaccine was introduced in 1921 and remains the only licensed vaccine for the prevention of TB worldwide. Despite its extensive use, the BCG vaccine lacks the ability to fully control the TB-endemic and -pandemic situations. The BCG vaccine is most effective in preventing pediatric TB, in particular, miliary TB and tuberculous meningitis. However, it has a limited effect in preventing pulmonary TB, which occurs more frequently in adults. BCG vaccination has now been implemented in more than 157 countries worldwide. For various countries, the benefits of vaccination are only limited and potentially not cost effective. The International Union Against Tuberculosis and Lung Diseases had set the criteria for discontinuation of BCG vaccination in 1994. This decision, however, was not based on economic considerations. Many developed countries have met the criteria set by the International Union Against Tuberculosis and Lung Disease and stopped universal BCG vaccination. For developing countries, the BCG vaccine is still an effective intervention in protecting young children from TB infection. A lot of effort has been spent on R&D of new TB vaccines, the first of which are expected to be available within 5–7 years from now. Novel TB vaccines are expected to be better and more effective than the current BCG vaccine and should provide a viable strategy in controlling TB morbidity and mortality. In this review, the aim is to explore economic evaluations that have been carried out for vaccination against TB worldwide. In addition to epidemiological evidence, economic evidence can play a crucial role in supporting the governments of countries in making proper public health decisions on BCG vaccination policies, in particular, to implement, continue, or discontinue.