Combining serological and contact data to derive target immunity levels for achieving and maintaining measles elimination.

BACKGROUND: Vaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90-95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns. METHODS: We combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination. RESULTS: We found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5-9-year-olds than established previously. CONCLUSIONS: The immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5-9-year-olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.

Transitioning Lessons Learned and Assets of the Global Polio Eradication Initiative to Global and Regional Measles and Rubella Elimination.

The Global Polio Eradication Initiative has built an extensive infrastructure with capabilities and resources that should be transitioned to measles and rubella elimination efforts. Measles continues to be a major cause of child mortality globally, and rubella continues to be the leading infectious cause of birth defects. Measles and rubella eradication is feasible and cost saving. The obvious similarities in strategies between polio elimination and measles and rubella elimination include the use of an extensive surveillance and laboratory network, outbreak preparedness and response, extensive communications and social mobilization networks, and the need for periodic supplementary immunization activities. Polio staff and resources are already connected with those of measles and rubella, and transitioning existing capabilities to measles and rubella elimination efforts allows for optimized use of resources and the best opportunity to incorporate important lessons learned from polio eradication, and polio resources are concentrated in the countries with the highest burden of measles and rubella. Measles and rubella elimination strategies rely heavily on achieving and maintaining high vaccination coverage through the routine immunization activity infrastructure, thus creating synergies with immunization systems approaches, in what is termed a "diagonal approach."

Development of a District-Level Programmatic Assessment Tool for Risk of Measles Virus Transmission.

All six World Health Organization (WHO) regions have now set goals for measles elimination by or before 2020. To prioritize measles elimination efforts and use available resources efficiently, there is a need to identify at-risk areas that are offtrack from meeting performance targets and require strengthening of programmatic efforts. This article describes the development of a WHO measles programmatic risk assessment tool to be used for monitoring, guiding, and sustaining measles elimination efforts at the subnational level. We outline the tool development process; the tool specifications and requirements for data inputs; the framework of risk categories, indicators, and scoring; and the risk category assignment. Overall risk was assessed as a function of indicator scores that fall into four main categories: population immunity, surveillance quality, program performance, and threat assessment. On the basis of the overall score, the tool assigns each district a risk of either low, medium, high, or very high. The cut-off criteria for the risk assignment categories were based on the distribution of scores from all possible combinations of individual indicator cutoffs. The results may be used for advocacy to communicate risk to policymakers, mobilize resources for corrective actions, manage population immunity, and prioritize programmatic activities. Ongoing evaluation of indicators will be needed to evaluate programmatic performance and plan risk mitigation activities effectively. The availability of a comprehensive tool that can identify at-risk districts will enhance efforts to prioritize resources and implement strategies for achieving the Global Vaccine Action Plan goals for measles elimination.

Rubella.

Rubella remains an important pathogen worldwide, with roughly 100,000 cases of congenital rubella syndrome estimated to occur every year. Rubella-containing vaccine is highly effective and safe and, as a result, endemic rubella transmission has been interrupted in the Americas since 2009. Incomplete rubella vaccination programmes result in continued disease transmission, as evidenced by recent large outbreaks in Japan and elsewhere. In this Seminar, we provide present results regarding rubella control, elimination, and eradication policies, and a brief review of new laboratory diagnostics. Additionally, we provide novel information about rubella-containing vaccine immunogenetics and review the emerging evidence of interindividual variability in humoral and cell-mediated innate and adaptive immune responses to rubella-containing vaccine and their association with haplotypes and single-nucleotide polymorphisms across the human genome.

Real-Time Monitoring of Vaccination Campaign Performance Using Mobile Phones - Nepal, 2016.

In 2012, the Global Vaccine Action Plan* established a goal to achieve measles and rubella elimination in five of the six World Health Organization (WHO) regions (194 countries) by 2020 (1). Measles elimination strategies aim to achieve ≥95% coverage with 2 routine doses of measles-containing vaccine (2), and implement supplementary immunization activities (SIAs)† in settings where routine coverage is low or where there are subpopulations at high risk. To ensure SIA quality and to achieve ≥95% SIA coverage nationally, rapid convenience monitoring (RCM) is used during or immediately after SIAs (3,4). The objective of RCM is to find unvaccinated children and to identify reasons for nonvaccination in areas with persons at high risk, to enable immediate implementation of corrective actions (e.g., reassigning teams to poorly vaccinated areas, modifying the timing of vaccination, or conducting mop-up vaccination activities). This report describes pilot testing of RCM using mobile phones (RCM-MP) during the second phase of an SIA in Nepal in 2016. Use of RCM-MP resulted in 87% timeliness and 94% completeness of data reporting and found that, although 95% of children were vaccinated, 42% of areas required corrective vaccination activities. RCM-MP challenges included connecting to mobile networks, small phone screen size, and capturing Global Positioning System (GPS) coordinates. Nonetheless, use of RCM-MP led to faster data transmission, analysis, and decision-making and to increased accountability among levels of the health system.

Progress Toward Regional Measles Elimination - Worldwide, 2000-2015.

Adopted in 2000, United Nations Millennium Development Goal 4 set a target to reduce child mortality by two thirds by 2015, with measles vaccination coverage as one of the progress indicators. In 2010, the World Health Assembly (WHA) set three milestones for measles control by 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district; 2) reduce global annual measles incidence to <5 cases per 1 million population; and 3) reduce global measles mortality by 95% from the 2000 estimate (1,2).* In 2012, WHA endorsed the Global Vaccine Action Plan† with the objective to eliminate measles in four World Health Organization (WHO) regions by 2015. Countries in all six WHO regions have adopted measles elimination goals. Measles elimination is the absence of endemic measles transmission in a region or other defined geographical area for ≥12 months in the presence of a well performing surveillance system. This report updates a previous report (3) and describes progress toward global measles control milestones and regional measles elimination goals during 2000-2015. During this period, annual reported measles incidence decreased 75%, from 146 to 36 cases per 1 million persons, and annual estimated measles deaths decreased 79%, from 651,600 to 134,200. However, none of the 2015 milestones or elimination goals were met. Countries and their partners need to act urgently to secure political commitment, raise the visibility of measles, increase vaccination coverage, strengthen surveillance, and mitigate the threat of decreasing resources for immunization once polio eradication is achieved.

Progress Toward Measles Elimination - Nepal, 2007-2014.

In 2013, the 66th session of the Regional Committee of the World Health Organization (WHO) South-East Asia Region (SEAR) established a goal to eliminate measles and to control rubella and congenital rubella syndrome (CRS) in SEAR by 2020. Current recommended measles elimination strategies in the region include 1) achieving and maintaining ≥95% coverage with 2 doses of measles-containing vaccine (MCV) in every district, delivered through the routine immunization program or through supplementary immunization activities (SIAs); 2) developing and sustaining a sensitive and timely measles case-based surveillance system that meets minimum recommended performance indicators; 3) developing and maintaining an accredited measles laboratory network; and 4) achieving timely identification, investigation, and response to measles outbreaks. In 2013, Nepal, one of the 11 SEAR member states, adopted a goal for national measles elimination by 2019. This report updates a previous report and summarizes progress toward measles elimination in Nepal during 2007-2014. During 2007-2014, estimated coverage with the first MCV dose (MCV1) increased from 81% to 88%. Approximately 3.9 and 9.7 million children were vaccinated in SIAs conducted in 2008 and 2014, respectively. Reported suspected measles incidence declined by 13% during 2007-2014, from 54 to 47 cases per 1 million population. However, in 2014, 81% of districts did not meet the measles case-based surveillance performance indicator target of ≥2 discarded non-measles cases per 100,000 population per year. To achieve and maintain measles elimination, additional measures are needed to strengthen routine immunization services to increase coverage with MCV1 and a recently introduced second dose of MCV (MCV2) to ≥95% in all districts, and to enhance sensitivity of measles case-based surveillance by adopting a more sensitive case definition, expanding case-based surveillance sites nationwide, and ensuring timely transport of specimens to the accredited national laboratory.

Global Measles and Rubella Laboratory Network Support for Elimination Goals, 2010-2015.

In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan (GVAP)* with the objective to eliminate measles and rubella in five World Health Organization (WHO) regions by 2020. In September 2013, countries in all six WHO regions had established measles elimination goals, and additional goals for elimination of rubella and congenital rubella syndrome were established in three regions (1). Capacity for surveillance, including laboratory confirmation, is fundamental to monitoring and verifying elimination. The 2012-2020 Global Measles and Rubella Strategic Plan of the Measles and Rubella Initiative(†) calls for effective case-based surveillance with laboratory testing for case confirmation (2). In 2000, the WHO Global Measles and Rubella Laboratory Network (GMRLN) was established to provide high quality laboratory support for surveillance (3). The GMRLN is the largest globally coordinated laboratory network, with 703 laboratories supporting surveillance in 191 countries. During 2010-2015, 742,187 serum specimens were tested, and 27,832 viral sequences were reported globally. Expansion of the capacity of the GMRLN will support measles and rubella elimination efforts as well as surveillance for other vaccine-preventable diseases (VPDs), including rotavirus, and for emerging pathogens of public health concern.

Global Progress Toward Rubella and Congenital Rubella Syndrome Control and Elimination - 2000-2014.

Rubella virus usually causes a mild fever and rash in children and adults. However, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or a constellation of congenital malformations known as congenital rubella syndrome (CRS). In 2011, the World Health Organization (WHO) updated guidance on the preferred strategy for introduction of rubella-containing vaccine (RCV) into national routine immunization schedules, including an initial vaccination campaign usually targeting children aged 9 months-15 years . The Global Vaccine Action Plan endorsed by the World Health Assembly in 2012 and the Global Measles and Rubella Strategic Plan (2012-2020) published by Measles and Rubella Initiative partners in 2012 both include goals to eliminate rubella and CRS in at least two WHO regions by 2015, and at least five WHO regions by 2020 (2,3). This report updates a previous report and summarizes global progress toward rubella and CRS control and elimination during 2000-2014. As of December 2014, RCV had been introduced in 140 (72%) countries, an increase from 99 (51%) countries in 2000 (for this report, WHO member states are referred to as countries). Reported rubella cases declined 95%, from 670,894 cases in 102 countries in 2000 to 33,068 cases in 162 countries in 2014, although reporting is inconsistent. To achieve the 2020 Global Vaccine Action Plan rubella and CRS elimination goals, RCV introduction needs to continue as country criteria indicating readiness are met, and rubella and CRS surveillance need to be strengthened to ensure that progress toward elimination can be measured.

Progress toward regional measles elimination - worldwide, 2000-2014.

In 2000, the United Nations General Assembly adopted the Millennium Development Goals (MDG), with MDG4 being a two-thirds reduction in child mortality by 2015, and with measles vaccination coverage being one of the three indicators of progress toward this goal.* In 2010, the World Health Assembly established three milestones for measles control by 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district; 2) reduce global annual measles incidence to fewer than five cases per million population; and 3) reduce global measles mortality by 95% from the 2000 estimate (1).† In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan§ with the objective to eliminate measles in four World Health Organization (WHO) regions by 2015. WHO member states in all six WHO regions have adopted measles elimination goals. This report updates the 2000­2013 report (2) and describes progress toward global control and regional measles elimination during 2000­2014. During this period, annual reported measles incidence declined 73% worldwide, from 146 to 40 cases per million population, and annual estimated measles deaths declined 79%, from 546,800 to 114,900. However, progress toward the 2015 milestones and elimination goals has slowed markedly since 2010. To resume progress toward milestones and goals for measles elimination, a review of current strategies and challenges to improving program performance is needed, and countries and their partners need to raise the visibility of measles elimination, address barriers to measles vaccination, and make substantial and sustained additional investments in strengthening health systems.

Progress toward regional measles elimination--worldwide, 2000-2013.

In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan with the objective to eliminate measles in four World Health Organization (WHO) regions by 2015. Member states of all six WHO regions have adopted measles elimination goals. In 2010, the World Health Assembly established three milestones for 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district; 2) reduce global annual measles incidence to <5 cases per million; and 3) reduce global measles mortality by 95% from the 2000 estimate. This report updates the 2000-2012 report and describes progress toward global control and regional measles elimination during 2000-2013. During this period, annual reported measles incidence declined 72% worldwide, from 146 to 40 per million population, and annual estimated measles deaths declined 75%, from 544,200 to 145,700. Four of six WHO regions have established regional verification commissions (RVCs); in the European (EUR) and Western Pacific regions (WPR), 19 member states successfully documented the absence of endemic measles. Resuming progress toward 2015 milestones and elimination goals will require countries and their partners to raise the visibility of measles elimination, address barriers to measles vaccination, and make substantial and sustained additional investments in strengthening health systems.

Global control and regional elimination of measles, 2000-2012.

In 2010, the World Health Assembly established three milestones toward global measles eradication to be reached by 2015: 1) increase routine coverage with the first dose of measles-containing vaccine (MCV1) for children aged 1 year to ≥90% nationally and ≥80% in every district, 2) reduce and maintain annual measles incidence at <5 cases per million, and 3) reduce measles mortality by 95% from the 2000 estimate. After the adoption by member states of the South-East Asia Region (SEAR) of the goal of measles elimination by 2020, elimination goals have been set by member states of all six World Health Organization (WHO) regions, and reaching measles elimination in four WHO regions by 2015 is an objective of the Global Vaccine Action Plan (GVAP). This report updates the previous report for 2000-2011 and describes progress toward global control and regional elimination of measles during 2000-2012. During this period, increases in routine MCV coverage, plus supplementary immunization activities (SIAs) reaching 145 million children in 2012, led to a 77% decrease worldwide in reported measles annual incidence, from 146 to 33 per million population, and a 78% decline in estimated annual measles deaths, from 562,400 to 122,000. Compared with a scenario of no vaccination, an estimated 13.8 million deaths were prevented by measles vaccination during 2000-2012. Achieving the 2015 targets and elimination goals will require countries and their partners to raise the visibility of measles elimination and make substantial and sustained additional investments in strengthening health systems.

Progress toward measles elimination--Eastern Mediterranean Region, 2008-2012.

In 1997, the 22 countries in the World Health Organization (WHO) Eastern Mediterranean Region (EMR) adopted a goal of measles elimination by 2010. To achieve this goal, the WHO Regional Office for the Eastern Mediterranean Region (EMRO) developed a four-pronged strategy: 1) achieve ≥ 95% vaccination coverage of children with the first dose of measles-containing vaccine (MCV1) in every district of each country through routine immunization services, 2) achieve ≥ 95% vaccination coverage with the second dose of measles-containing vaccine (MCV2) in every district of each country either through a routine 2-dose vaccination schedule or through supplementary immunization activities (SIAs), 3) conduct high-quality, case-based surveillance in all countries, and 4) provide optimal clinical case management, including supplementing diets with vitamin A. Although significant progress was made toward measles elimination in the EMR during 1997-2007, the measles elimination goal was not reached by the target date of 2010, and the date was revised to 2015. This report updates previous reports and summarizes the progress made toward measles elimination in EMR during 2008-2012. From 2008 to 2012, large outbreaks occurred in countries with a high incidence of measles, and reported annual measles cases in EMR increased from 12,186 to 36,456. To achieve measles elimination in EMR, efforts are needed to increase 2-dose vaccination coverage, especially in countries with high incidence of measles and in conflict-affected countries, and to implement innovative strategies to reach populations at high risk in areas with poor access to vaccination services or with civil strife.

Progress toward measles preelimination--African Region, 2011-2012.

In 2008, the 46 member states of the World Health Organization (WHO) African Region (AFR) adopted a measles preelimination goal to reach by the end of 2012 with the following targets: 1) >98% reduction in estimated regional measles mortality compared with 2000, 2) annual measles incidence of fewer than five reported cases per million population nationally, 3) >90% national first dose of measles-containing vaccine (MCV1) coverage and >80% MCV1 coverage in all districts, and 4) >95% MCV coverage in all districts by supplementary immunization activities (SIAs). Surveillance performance objectives were to report two or more cases of nonmeasles febrile rash illness per 100,000 population, one or more suspected measles cases investigated with blood specimens in ≥80% of districts, and 100% completeness of surveillance reporting from all districts. This report updates previous reports and describes progress toward the measles preelimination goal during 2011-2012. In 2012, 13 (28%) member states had >90% MCV1 coverage, and three (7%) reported >90% MCV1 coverage nationally and >80% coverage in all districts. During 2011-2012, four (15%) of 27 SIAs with available information met the target of >95% coverage in all districts. In 2012, 16 of 43 (37%) member states met the incidence target of fewer than five cases per million, and 19 of 43 (44%) met both surveillance performance targets. In 2011, the WHO Regional Committee for AFR established a goal to achieve measles elimination by 2020. To achieve this goal, intensified efforts to identify and close population immunity gaps and improve surveillance quality are needed, as well as committed leadership and ownership of the measles elimination activities and mobilization of adequate resources to complement funding from global partners.

Evolution and Contribution of a Global Partnership against Measles and Rubella, 2001-2023.

This article describes the arc of global measles and rubella elimination since 2000 from the perspective of the founding partners of the Measles Initiative. The Measles Initiative was formed in 2001 as a partnership among the American Red Cross, the Centers for Disease Control and Prevention, UNICEF, the United Nations Foundation, and the World Health Organization with the aim to reduce measles deaths in low-income countries. Recognizing rubella as the leading infectious disease cause of congenital abnormalities globally and achievement of measles and rubella elimination in the region of the Americas, the partnership was renamed the Measles and Rubella Initiative (MRI) in 2012. The goals of the MRI were at least a 95% reduction in global measles mortality and elimination of measles and rubella in at least five of the six WHO regions. In January 2023, the membership of the partnership was expanded to include the Bill and Melinda Gates Foundation (BMGF) and Gavi the Vaccine Alliance, and its name changed to the IA2030 Measles and Rubella Partnership. We describe the role the partnership has had in measles partner effectiveness and its impact on measles and rubella disease burden, including how the partnership has strategically adapted to the evolving immunization landscape. We conclude with lessons learned regarding the role global partnerships can play in furthering the impact of disease control programs within the current global immunization environment.

Assessment of the 2010 global measles mortality reduction goal: results from a model of surveillance data.

BACKGROUND: In 2008 all WHO member states endorsed a target of 90% reduction in measles mortality by 2010 over 2000 levels. We developed a model to estimate progress made towards this goal. METHODS: We constructed a state-space model with population and immunisation coverage estimates and reported surveillance data to estimate annual national measles cases, distributed across age classes. We estimated deaths by applying age-specific and country-specific case-fatality ratios to estimated cases in each age-country class. FINDINGS: Estimated global measles mortality decreased 74% from 535,300 deaths (95% CI 347,200-976,400) in 2000 to 139,300 (71,200-447,800) in 2010. Measles mortality was reduced by more than three-quarters in all WHO regions except the WHO southeast Asia region. India accounted for 47% of estimated measles mortality in 2010, and the WHO African region accounted for 36%. INTERPRETATION: Despite rapid progress in measles control from 2000 to 2007, delayed implementation of accelerated disease control in India and continued outbreaks in Africa stalled momentum towards the 2010 global measles mortality reduction goal. Intensified control measures and renewed political and financial commitment are needed to achieve mortality reduction targets and lay the foundation for future global eradication of measles. FUNDING: US Centers for Disease Control and Prevention (PMS 5U66/IP000161).

Ethical considerations for vaccination programmes in acute humanitarian emergencies.

Humanitarian emergencies result in a breakdown of critical health-care services and often make vulnerable communities dependent on external agencies for care. In resource-constrained settings, this may occur against a backdrop of extreme poverty, malnutrition, insecurity, low literacy and poor infrastructure. Under these circumstances, providing food, water and shelter and limiting communicable disease outbreaks become primary concerns. Where effective and safe vaccines are available to mitigate the risk of disease outbreaks, their potential deployment is a key consideration in meeting emergency health needs. Ethical considerations are crucial when deciding on vaccine deployment. Allocation of vaccines in short supply, target groups, delivery strategies, surveillance and research during acute humanitarian emergencies all involve ethical considerations that often arise from the tension between individual and common good. The authors lay out the ethical issues that policy-makers need to bear in mind when considering the deployment of mass vaccination during humanitarian emergencies, including beneficence (duty of care and the rule of rescue), non-maleficence, autonomy and consent, and distributive and procedural justice.

Les urgences humanitaires entraînent une rupture des services de soins de santé essentiels et elles rendent souvent les communautés vulnérables dépendantes des organismes externes pour leurs soins. Dans les milieux où les ressources sont comptées, cela peut se produire sur fond d'extrême pauvreté, de malnutrition, d'insécurité, de faible niveau d'alphabétisation et d'infrastructures insuffisantes. Dans ces circonstances, fournir nourriture, eau et abri, tout en limitant les épidémies de maladies transmissibles, devient une préoccupation centrale. Lorsqu'il existe des vaccins sûrs et efficaces pour limiter les risques d'épidémies, leur éventuel déploiement est un facteur clé pour satisfaire les besoins sanitaires d'urgence. Les considérations éthiques sont essentielles pour se prononcer sur le déploiement de la vaccination. La distribution de vaccins en quantités limitées, les groupes cibles, les stratégies de vaccination, la surveillance et la recherche lors de situations d'urgence humanitaire graves impliquent tous des considérations éthiques souvent nées de la tension entre le bien individuel et le bien commun. Les auteurs exposent les questions éthiques que les décideurs doivent garder à l'esprit lorsqu'ils envisagent le déploiement d'une vaccination de masse pendant les urgences humanitaires, notamment la bénéficience (devoir de diligence et devoir d'assistance), la non-maléficience, l'autonomie et le consentement, ainsi que la justice de répartition et l'équité procédurale.

Las emergencias humanitarias causan el desplome de los servicios de atención de salud esenciales y, a menudo, provocan que la atención sanitaria de las comunidades vulnerables pase a depender de organismos externos. En entornos con recursos limitados esto puede darse en un contexto de pobreza extrema, desnutrición, inseguridad, bajos niveles de alfabetización e infraestructuras deficientes. Bajo estas circunstancias, suministrar alimentos, agua y refugio, así como limitar la aparición de brotes de enfermedades transmisibles representan las principales preocupaciones. Cuando se dispone de vacunas eficaces y seguras para reducir el riesgo de aparición de brotes de enfermedades, la distribución potencial de las mismas constituye un factor clave en las situaciones de emergencia sanitaria. Las consideraciones éticas son fundamentales a la hora de decidir sobre la distribución de las vacunas. La asignación de vacunas con suministro limitado, los grupos destinatarios de las mismas, las estrategias de entrega, así como la monitorización y los estudios durante las emergencias humanitarias graves implican consideraciones éticas que, a menudo, derivan de un enfrentamiento entre el beneficio individual y el bien común. Los autores exponen los problemas éticos que los responsables políticos deben tener en cuenta a la hora de considerar cómo distribuir la vacunación masiva durante las emergencias humanitarias, lo cual incluye principios como la beneficencia (el deber de atención y la regla del rescate), la no maleficencia, la autonomía y el consentimiento, así como la justicia distributiva y procesal.

Biological feasibility of measles eradication.

Recent progress in reducing global measles mortality has renewed interest in measles eradication. Three biological criteria are deemed important for disease eradication: (1) humans are the sole pathogen reservoir; (2) accurate diagnostic tests exist; and (3) an effective, practical intervention is available at reasonable cost. Interruption of transmission in large geographical areas for prolonged periods further supports the feasibility of eradication. Measles is thought by many experts to meet these criteria: no nonhuman reservoir is known to exist, accurate diagnostic tests are available, and attenuated measles vaccines are effective and immunogenic. Measles has been eliminated in large geographical areas, including the Americas. Measles eradication is biologically feasible. The challenges for measles eradication will be logistical, political, and financial.

Strategic planning for measles control: using data to inform optimal vaccination strategies.

BACKGROUND: In response to repeated requests for assistance in evaluating the health benefit and cost implications of adjustments to national measles immunization strategies, the World Health Organization (WHO) has developed the Measles Strategic Planning (MSP) tool to harness routinely available data to estimate effectiveness and cost effectiveness of vaccination strategies. METHOD: The MSP tool estimates measles incidence and mortality through a country-specific cohort model, using a probability of infection dependent on population immunity levels. This method approximates measles transmission dynamics without requiring detailed data that would prohibit use in low- and middle-income countries. Coupled with cost data, the tool estimates incremental costs and cost effectiveness of user-defined vaccination strategies over 5-10 year planning periods. RESULTS: The MSP tool produces valid estimates of measles incidence in settings with low to moderate vaccination coverage. Early adopters report that the tool facilitates decision making by minimizing the amount of time required to assess the impact of vaccination strategies on population immunity. CONCLUSIONS: By clearly illustrating what vaccination strategies can effectively protect against measles at the least cost to immunization programs, the MSP tool supports evidence-based decision making for effective and comprehensive measles control.