Emerging and Reemerging Aedes-Transmitted Arbovirus Infections in the Region of the Americas: Implications for Health Policy.

The increasing geographical spread and disease incidence of arboviral infections are among the greatest public health concerns in the Americas. The region has observed an increasing trend in dengue incidence in the last decades, evolving from low to hyperendemicity. Yellow fever incidence has also intensified in this period, expanding from sylvatic-restricted activity to urban outbreaks. Chikungunya started spreading pandemically in 2005 at an unprecedented pace, reaching the Americas in 2013. The following year, Zika also emerged in the region with an explosive outbreak, carrying devastating congenital abnormalities and neurologic disorders and becoming one of the greatest global health crises in years. The inadequate arbovirus surveillance in the region and the lack of serologic tests to differentiate among viruses poses substantial challenges. The evidence for vector control interventions remains weak. Clinical management remains the mainstay of arboviral disease control. Currently, only yellow fever and dengue vaccines are licensed in the Americas, with several candidate vaccines in clinical trials. The Global Arbovirus Group of Experts provides in this article an overview of progress, challenges, and recommendations on arboviral prevention and control for countries of the Americas.

Development of a cholera vaccination policy on the Island of Hispaniola, 2010-2013.

Deployment of oral cholera vaccine (OCV) on the Island of Hispaniola has been considered since the emergence of the disease in October of 2010. At that time, emergency response focused on the time-tested measures of treatment to prevent deaths and sanitation to diminish transmission. Use of the limited amount of vaccine available in the global market was recommended for demonstration activities, which were carried out in 2012. As transmission continues, vaccination was recommended in Haiti as one component of a comprehensive initiative supported by an international coalition to eliminate cholera on the Island of Hispaniola. Leveraging its delivery to strengthen other cholera prevention measures and immunization services, a phased OCV introduction is pursued in accordance with global vaccine supply. Not mutually exclusive or sequential deployment options include routine immunization for children over the age of 1 year and campaigns in vulnerable metropolitan areas or rural areas with limited access to health services.

Systematic documentation of new vaccine introduction in selected countries of the Latin American Region.

BACKGROUND: Countries in Latin America were among the first developing countries to introduce new vaccines, particularly rotavirus (RV) and pneumococcal conjugate vaccines (PCVs), into their national immunization schedules. Experiences and lessons learned from these countries are valuable to donors, immunization partners, and policy makers in other countries wishing to make informed decisions on vaccine introduction. OBJECTIVES: In order to enhance knowledge and promote understanding of the process of new vaccine introduction in the Latin American Region, with particular focus on RV and PCV, we conducted a systematic qualitative assessment. We evaluated the decision-making process, documented the structure in place, and reviewed key factors pertaining to new vaccine introduction. These include country morbidity and mortality data available prior to vaccine introduction, funding sources and mechanisms for vaccine introduction, challenges of implementation, and assessment of vaccine impact. METHODS: From March 2010 to April 2011, we evaluated a subset of countries that had introduced RV and/or PCV in the past five years through interviews with key informants at the country level and through a systematic review of published data, gray literature, official technical documents, and country-specific health indicators. Countries evaluated were Bolivia, Brazil, Nicaragua, Peru, and Venezuela. RESULTS: In all countries, the potential of new vaccines to reduce mortality, as established by Millennium Development Goal 4, was an important consideration leading to vaccine introduction. Several factors-the availability of funds, the existence of sufficient evidence for vaccine introduction, and the feasibility of sustainable financing-were identified as crucial components of the decision-making process in the countries evaluated. CONCLUSIONS: The decision making process regarding new vaccine introduction in the countries evaluated does not follow a systematic approach. Nonetheless, existing evidence on efficacy, potential impact, and cost-effectiveness of vaccine introduction, even if not local data, was important in the decision making process for vaccine introduction.

TRIVAC decision-support model for evaluating the cost-effectiveness of Haemophilus influenzae type b, pneumococcal and rotavirus vaccination.

The TRIVAC decision support model has been used widely in Latin America and other regions to help national teams evaluate the cost-effectiveness of Haemophilus influenzae type b (Hib) vaccine, pneumococcal conjugate vaccine (PCV) and rotavirus vaccine (RV). We describe the structure and functioning of this model, and identify the parameters with the greatest influence on the results. The TRIVAC model is a spreadsheet software program that calculates incremental cost-effectiveness ratios (ICERs) and other indicators for three childhood vaccines (Hib, PCV and RV) utilising parameters such as demography, disease burden, vaccine costs, vaccine coverage, vaccine efficacy, health service utilisation and costs. There is a good deal of uncertainty about the local values of many of the parameters that have most influence on the cost-effectiveness of these new vaccines. Cost-effectiveness models can be used to explore the implications of different values of these parameters. However, for such models to be seen as relevant and helpful by decision-makers, they need to be transparent, flexible, easy to use, and embedded in a process which is owned and led by national teams. In this paper the key drivers of cost-effectiveness in the model are identified by one-way sensitivity analyses, run for each vaccine in 147 countries. The data used are mainly from standard international sources and the published literature. The primary indicator was the discounted cost per Disability Adjusted Life-Year (DALY) averted, from a government perspective, over a 20-year period (2013-2032). For all three vaccines, the ICER was most sensitive to changes in relative coverage (the coverage of the children who would have become diseased or, more importantly, died if the population had not been vaccinated, as a % of overall national coverage) and the herd effect multiplier. Other influential parameters for all three vaccines were: the incidence and case fatality of disease, the baseline trend in disease mortality in the absence of vaccination, vaccine efficacy, vaccine price and the % decline in vaccine price per year. Important vaccine-specific parameters included the cost of Hib meningitis sequelae, PCV serotype coverage and the rotavirus gastro-enteritis (RVGE) admission rate. While vaccine efficacy, herd effects, disease mortality and vaccine price are commonly cited as important drivers of cost-effectiveness, this analysis highlights the potentially important influence of relative coverage, a parameter rarely considered in models of vaccine impact and cost-effectiveness.

Critical issues in implementing a national integrated all-vaccine preventable disease surveillance system.

In 2007, the World Health Organization published the Global Framework for Immunization Monitoring and Surveillance (GFIMS) outlining measures to enhance national surveillance for vaccine preventable diseases (VPDs). The GFIMS emphasized that VPD surveillance should be integrated and placed in a 'unified framework' building upon the strengths of existing surveillance systems to prevent duplication of activities common to all surveillance systems and to minimize human resource and supply expenditures. Unfortunately, there was little experience in actually developing integrated VPD surveillance. We describe the process of developing operational guidance for ministries of health to implement such an integrated surveillance system for multiple VPDs.

Vaccination legislation in Latin America and the Caribbean.

Governments have the authority and responsibility to ensure vaccination for all citizens. The development of vaccination legislation in Latin America and the Caribbean (LAC) parallels the emergence of sustainable, relatively autonomous, and effective national immunization programs. We reviewed vaccination legislation and related legal documents from LAC countries (excluding Canada, Puerto Rico, the United States, and the US Virgin Islands), and described and assessed vaccination legislation provisions. Twenty-seven of the 44 countries and territories in the Region have proposed or enacted vaccination legislation. Provisions vary substantially, but legal frameworks generally protect the sustainability of the immunization program, the individual's right to immunization, and the state's responsibility to provide it as a public good. Of the legislation from countries and territories included in the analysis, 44 per cent protects a budget line for vaccines, 96 per cent mandates immunization, 63 per cent declares immunization a public good, and 78 per cent explicitly defines the national vaccine schedule. We looked for associations between vaccination legislation in LAC and national immunization program performance and financing, and conclude with lessons for governments seeking to craft or enhance vaccination legislation.

Potential intussusception risk versus health benefits from rotavirus vaccination in Latin America.

BACKGROUND: With the recent postlicensure identification of an increased risk of intussusception with rotavirus vaccine, the 14 Latin American countries currently using rotavirus vaccine must now weigh the health benefits versus risks to assess whether to continue vaccination. To inform policy considerations, we estimated excess intussusception cases and mortality potentially caused by rotavirus vaccine for each of the 14 countries and compared these estimates to hospitalizations and deaths expected to be averted through vaccination. METHODS: We used regional rotavirus disease burden and rotavirus vaccine efficacy data, global natural intussusception and regional rotavirus vaccine-related risk estimates, and country-specific diphtheria, tetanus, and pertussus vaccination coverage rates to estimate rotavirus vaccine coverage rates. We performed a probabilistic sensitivity analysis to account for uncertainty in these parameters. RESULTS: For an aggregate hypothetical birth cohort of 9.5 million infants in these 14 countries, rotavirus vaccine would annually prevent 144 746 (90% confidence interval [CI], 128 821-156 707) hospitalizations and 4124 deaths (90% CI, 3740-4239) due to rotavirus in their first 5 years of life but could cause an additional 172 hospitalizations (90% CI, 126-293) and 10 deaths (90% CI, 6-17) due to intussusception, yielding benefit-risk ratios for hospitalization and death of 841:1 (90% CI, 479:1 to 1142:1) and 395:1 (90% CI, 207:1 to 526:1), respectively. In an uncertainty analysis using 10 000 simulations of our probabilistic parameters, in comparing rotavirus disease averted to intussusception events caused, the hospitalization ratio was never below 100:1, and our death ratio fell below 100:1 only once. CONCLUSIONS: The health benefits of vaccination far outweigh the short-term risks and support continued rotavirus vaccination in Latin America.

Performing Country-led Economic Evaluations to Inform Immunization Policy: ProVac Experiences in Latin America and the Caribbean.

New vaccines have been demonstrated to be effective in reducing morbidity and mortality, particularly in children, but come at increased costs to societies, governments, and their national immunization programs compared with other traditional childhood vaccines. Rational allocation of available resources requires systematic collection of the evidence base to decide whether to introduce a new vaccine, an important component of which is cost-effectiveness analysis. In this article, we develop in-depth case studies to examine the country experience of conducting cost-effectiveness analysis with the support of Pan American Health Organization ProVac Initiative and the implications of its process for decision making on new vaccine introduction in Latin America and the Caribbean. Key lessons regarding how cost-effectiveness analysis may be effectively used to inform evidence-based immunization policy are highlighted, drawing from the experience of Nicaragua and Paraguay. Based on the lessons identified, the vision going forward will focus on promoting the sustainability of multidisciplinary country teams while continuing to prioritize capacity development as an overarching guiding principle for preparing countries to face future new vaccine policy decisions.

Strengthening the technical capacity at country-level to make informed policy decisions on new vaccine introduction: lessons learned by PAHO's ProVac Initiative.

Rotavirus, pneumococcal conjugate and HPV vaccines have the potential to make substantial gains in health, specifically in reducing child mortality and improving women's health. Decisions regarding new vaccine introduction should be grounded in a broad evidence base that reflects national conditions. In this paper, we describe the Pan American Health Organization ProVac Initiative's experience in strengthening national decision making regarding new vaccine introduction through five sets of activities: (1) strengthening infrastructure for decision making; (2) developing tools for economic analyses and providing training to national multidisciplinary teams; (3) collecting data, conducting analysis, and gathering a framework of evidence; (4) advocating for evidence-based decisions; and (5) effectively planning for new vaccine introduction when evidence supports it. Key lessons learned regarding the role of multidisciplinary country teams, provision of direct technical support, development of tools, and provision of distance and in-person training are highlighted.

Descriptive analysis of immunization policy decision making in the Americas / Análisis descriptivo de la toma de decisión sobre políticas de vacunación en las Américas

OBJECTIVES: Reducing and eliminating vaccine-preventable diseases requires evidence-based and informed policy decision making. Critical to determining the functionality of the decision-making process for introduction of a new vaccine is understanding the role of the national immunization technical advisory group (ITAG) in each country. The aim of this study is to document the current situation of national level immunization policy decision making for use in the Pan American Health Organization (PAHO) ProVac Initiative. METHODS: A structured 66-variable questionnaire developed by the World Health Organization (WHO) in collaboration with the University of Ottawa was distributed to all WHO regions; it was composed of dichotomous, multiple-choice, and open-ended questions. Questionnaires were e-mailed or faxed to the six WHO regional offices and the offices distributed them to all member states. This paper analyzes surveys from the Americas as part of PAHO's ProVac Initiative. RESULTS: Twenty-nine countries of the Americas answered the survey. They conveyed that immunization policy making needed to be improved and further supported by organizations such as PAHO. Areas of improvement ranged from organization and technical support to strengthening capacity and infrastructure to improved coordination among stakeholders. This survey also highlighted a variety of ITAG processes that need further investigation. CONCLUSION: This survey supports the efforts of PAHO's ProVac Initiative to disseminate knowledge and best practices for an immunization policy decision-making framework through the development of clear definitions and guidelines. By highlighting each problem noted in this study, ProVac will assist countries in Latin America and the Caribbean to build national capacity for making evidence-based decisions about introduction of new vaccines.

OBJETIVOS: Para reducir y eliminar las enfermedades prevenibles por vacunación se requiere tomar decisiones basadas en datos científicos y una política informada. Con el fin de determinar la funcionalidad del proceso de toma de decisiones para introducir una nueva vacuna es vital comprender el papel de los grupos técnicos asesores nacionales sobre vacunación (GTAN) de cada país. En este trabajo se documenta la situación actual de la toma de decisión sobre políticas de vacunación a nivel nacional como insumo de la Iniciativa ProVac de la Organización Panamericana de la Salud (OPS). MÉTODOS: Se distribuyó a todas las regiones de la Organización Mundial de la Salud (OMS) un cuestionario estructurado con 66 variables, desarrollado por la OMS en colaboración con la Universidad de Ottawa, Canadá. El cuestionario contenía preguntas abiertas, dicotómicas y de selección múltiple y se envió por correo electrónico o fax a las seis oficinas regionales de la OMS y estas lo distribuyeron a todos los estados miembros. En este manuscrito se analizan las respuestas procedentes de las Américas, como parte de la Iniciativa ProVac de la OPS. RESULTADOS: Respondieron la encuesta 29 países de las Américas. Todos coincidieron en que la formulación de políticas de vacunación debe mejorar y se necesita más apoyo de organizaciones como la OPS. Las áreas que requieren mejoras van desde la organización y el apoyo técnico hasta el fortalecimiento de la capacidad y la infraestructura, y el perfeccionamiento de la coordinación entre los diferentes actores. También se destacan algunos procesos de los GTAN que requieren mayor investigación. CONCLUSIÓN: Esta encuesta apoya los esfuerzos de la iniciativa ProVac de la OPS para diseminar el conocimiento y las mejores prácticas para elaborar un marco de trabajo para la toma de decisiones sobre políticas de vacunación mediante el desarrollo de definiciones y directivas claras. Al poner de manifiesto cada problema observado ...

Descriptive analysis of immunization policy decision making in the Americas.

OBJECTIVES: Reducing and eliminating vaccine-preventable diseases requires evidence-based and informed policy decision making. Critical to determining the functionality of the decision-making process for introduction of a new vaccine is understanding the role of the national immunization technical advisory group (ITAG) in each country. The aim of this study is to document the current situation of national level immunization policy decision making for use in the Pan American Health Organization (PAHO) ProVac Initiative. METHODS: A structured 66-variable questionnaire developed by the World Health Organization (WHO) in collaboration with the University of Ottawa was distributed to all WHO regions; it was composed of dichotomous, multiple-choice, and open-ended questions. Questionnaires were e-mailed or faxed to the six WHO regional offices and the offices distributed them to all member states. This paper analyzes surveys from the Americas as part of PAHO's ProVac Initiative. RESULTS: Twenty-nine countries of the Americas answered the survey. They conveyed that immunization policy making needed to be improved and further supported by organizations such as PAHO. Areas of improvement ranged from organization and technical support to strengthening capacity and infrastructure to improved coordination among stakeholders. This survey also highlighted a variety of ITAG processes that need further investigation. CONCLUSION: This survey supports the efforts of PAHO's ProVac Initiative to disseminate knowledge and best practices for an immunization policy decision-making framework through the development of clear definitions and guidelines. By highlighting each problem noted in this study, ProVac will assist countries in Latin America and the Caribbean to build national capacity for making evidence-based decisions about introduction of new vaccines.