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1.
Lancet Infect Dis ; 19(11): 1235-1245, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31548079

RESUMEN

BACKGROUND: Measles is an important cause of death in children, despite the availability of safe and cost-saving measles-containing vaccines (MCVs). The first MCV dose (MCV1) is recommended at 9 months of age in countries with ongoing measles transmission, and at 12 months in countries with low risk of measles. To assess whether bringing forward the age of MCV1 is beneficial, we did a systematic review and meta-analysis of the benefits and risks of MCV1 in infants younger than 9 months. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, Proquest, Global Health, the WHO library database, and the WHO Institutional Repository for Information Sharing database, and consulted experts. We included randomised and quasi-randomised controlled trials, outbreak investigations, and cohort and case-control studies without restriction on publication dates, in which MCV1 was administered to infants younger than 9 months. We did the literature search on June 2, 2015, and updated it on Jan 14, 2019. We assessed: proportion of infants seroconverted, geometric mean antibody titre, avidity, cellular immunity, duration of immunity, vaccine efficacy, vaccine effectiveness, and safety. We used random-effects models to derive pooled estimates of the endpoints, where appropriate. We assessed methodological quality using the Grading of Recommendations, Assessment, Development, and Evaluation guidelines. FINDINGS: Our search identified 1156 studies, of which 1071 were screened for eligibility. 351 were eligible for full-text screening, and data from 56 studies that met all inclusion criteria were used for analysis. The proportion of infants who seroconverted increased from 50% (95% CI 29-71) for those vaccinated with MCV1 at 4 months of age to 85% (69-97) for those were vaccinated at 8 months. The pooled geometric mean titre ratio for infants aged 4-8 months vaccinated with MCV1 compared with infants vaccinated with MCV1 at age 9 months or older was 0·46 (95% CI 0·33-0·66; I2=99·9%, p<0·0001). Only one study reported on avidity and suggested that there was lower avidity and a shorter duration of immunity following MCV1 administration at 6 months of age than at 9 months of age (p=0·0016) or 12 months of age (p<0·001). No effect of age at MCV1 administration on cellular immunity was found. One study reported that vaccine efficacy against laboratory-confirmed measles virus infection was 94% (95% CI 74-98) in infants vaccinated with MCV1 at 4·5 months of age. The pooled vaccine effectiveness of MCV1 in infants younger than 9 months against measles was 58% (95% CI 9-80; I2=84·9%, p<0·0001). The pooled vaccine effectiveness estimate from within-study comparisons of infants younger than 9 months vaccinated with MCV1 were 51% (95% CI -44 to 83; I2=92·3%, p<0·0001), and for those aged 9 months and older at vaccination it was 83% (76-88; I2=93·8%, p<0·0001). No differences in the risk of adverse events after MCV1 administration were found between infants younger than 9 months and those aged 9 months of older. Overall, the quality of evidence ranged from moderate to very low. INTERPRETATION: MCV1 administered to infants younger than 9 months induces a good immune response, whereby the proportion of infants seroconverted increases with increased age at vaccination. A large proportion of infants receiving MCV1 before 9 months of age are protected and the vaccine is safe, although higher antibody titres and vaccine effectiveness are found when MCV1 is administered at older ages. Recommending MCV1 administration to infants younger than 9 months for those at high risk of measles is an important step towards reducing measles-related mortality and morbidity. FUNDING: WHO.


Asunto(s)
Anticuerpos Antivirales/sangre , Esquemas de Inmunización , Vacuna Antisarampión/efectos adversos , Vacuna Antisarampión/inmunología , Virus del Sarampión/inmunología , Sarampión/prevención & control , Factores de Edad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Femenino , Humanos , Inmunidad Celular , Lactante , Masculino , Vacuna Antisarampión/administración & dosificación , Medición de Riesgo , Resultado del Tratamiento
2.
Lancet Infect Dis ; 19(11): 1246-1254, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31548081

RESUMEN

BACKGROUND: Vaccinating infants with a first dose of measles-containing vaccine (MCV1) before 9 months of age in high-risk settings has the potential to reduce measles-related morbidity and mortality. However, there is concern that early vaccination might blunt the immune response to subsequent measles vaccine doses. We systematically reviewed the available evidence on the effect of MCV1 administration to infants younger than 9 months on their immune responses to subsequent MCV doses. METHODS: For this systematic review and meta-analysis, we searched for randomised and quasi-randomised controlled trials, outbreak investigations, and cohort and case-control studies without restriction on publication dates, in which MCV1 was administered to infants younger than 9 months. We did the literature search on June 2, 2015, and updated it on Jan 14, 2019. We included studies reporting data on strength or duration of humoral and cellular immune responses, and on vaccine efficacy or vaccine effectiveness after two-dose or three-dose MCV schedules. Our outcome measures were proportion of seropositive infants, geometric mean titre, vaccine efficacy, vaccine effectiveness, antibody avidity index, and T-cell stimulation index. We used random-effects meta-analysis to derive pooled estimates of the outcomes, where appropriate. We assessed the methodological quality of included studies using Grading of Recommendation Assessment, Development and Evaluation (GRADE) guidelines. FINDINGS: Our search retrieved 1156 records and 85 were excluded due to duplication. 1071 records were screened for eligibility, of which 351 were eligible for full-text screening and 21 were eligible for inclusion in the review. From 13 studies, the pooled proportion of infants seropositive after two MCV doses, with MCV1 administered before 9 months of age, was 98% (95% CI 96-99; I2=79·8%, p<0·0001), which was not significantly different from seropositivity after a two-dose MCV schedule starting later (p=0·087). Only one of four studies found geometric mean titres after MCV2 administration to be significantly lower when MCV1 was administered before 9 months of age than at 9 months of age or later. There was insufficient evidence to determine an effect of age at MCV1 administration on antibody avidity. The pooled vaccine effectiveness estimate derived from two studies of a two-dose MCV schedule with MCV1 vaccination before 9 months of age was 95% (95% CI 89-100; I2=12·6%, p=0·29). Seven studies reporting on measles virus-specific cellular immune responses found that T-cell responses and T-cell memory were sustained, irrespective of the age of MCV1 administration. Overall, the quality of evidence was moderate to very low. INTERPRETATION: Our findings suggest that administering MCV1 to infants younger than 9 months followed by additional MCV doses results in high seropositivity, vaccine effectiveness, and T-cell responses, which are independent of the age at MCV1, supporting the vaccination of very young infants in high-risk settings. However, we also found some evidence that MCV1 administered to infants younger than 9 months resulted in lower antibody titres after one or two subsequent doses of MCV than when measles vaccination is started at age 9 months or older. The clinical and public-health relevance of this immunity blunting effect are uncertain. FUNDING: WHO.


Asunto(s)
Inmunidad Celular , Inmunidad Humoral , Esquemas de Inmunización , Vacuna Antisarampión/administración & dosificación , Vacuna Antisarampión/inmunología , Virus del Sarampión/inmunología , Sarampión/prevención & control , Factores de Edad , Anticuerpos Antivirales/sangre , Femenino , Humanos , Lactante , Masculino , Linfocitos T/inmunología , Resultado del Tratamiento
3.
BMC Med ; 17(1): 180, 2019 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-31551070

RESUMEN

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.


Asunto(s)
Trazado de Contacto/estadística & datos numéricos , Erradicación de la Enfermedad/métodos , Inmunidad Colectiva , Virus del Sarampión/inmunología , Sarampión/epidemiología , Sarampión/inmunología , Sarampión/prevención & control , Adolescente , Adulto , Niño , Preescolar , Erradicación de la Enfermedad/organización & administración , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/estadística & datos numéricos , Femenino , Geografía , Necesidades y Demandas de Servicios de Salud/estadística & datos numéricos , Humanos , Inmunidad Colectiva/fisiología , Incidencia , Lactante , Recién Nacido , Masculino , Sarampión/transmisión , Vacuna Antisarampión/uso terapéutico , Modelos Estadísticos , Estudios Seroepidemiológicos , Vacunación/estadística & datos numéricos , Adulto Joven
5.
J Infect Dis ; 216(suppl_1): S308-S315, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28838195

RESUMEN

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."


Asunto(s)
Erradicación de la Enfermedad/métodos , Erradicación de la Enfermedad/organización & administración , Salud Global , Sarampión/prevención & control , Poliomielitis/prevención & control , Rubéola (Sarampión Alemán)/prevención & control , Humanos , Vacunación
6.
Risk Anal ; 37(6): 1052-1062, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-25976980

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad/métodos , Vacuna Antisarampión/uso terapéutico , Sarampión/prevención & control , Medición de Riesgo , Niño , Preescolar , Geografía , Salud Global , Humanos , Programas de Inmunización , Incidencia , Lactante , Recién Nacido , Sarampión/epidemiología , Namibia , Filipinas , Vigilancia de la Población , Senegal , Organización Mundial de la Salud
7.
MMWR Morb Mortal Wkly Rep ; 65(44): 1228-1233, 2016 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-27832050

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Salud Global/estadística & datos numéricos , Sarampión/prevención & control , Adolescente , Adulto , Niño , Preescolar , Humanos , Programas de Inmunización , Incidencia , Lactante , Sarampión/epidemiología , Sarampión/mortalidad , Vacuna Antisarampión/administración & dosificación , Organización Mundial de la Salud , Adulto Joven
8.
MMWR Morb Mortal Wkly Rep ; 65(39): 1072-1076, 2016 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-27711034

RESUMEN

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.


Asunto(s)
Teléfono Celular , Programas de Inmunización , Vacuna Antisarampión/administración & dosificación , Vigilancia de la Población/métodos , Vacuna contra la Rubéola/administración & dosificación , Vacunación/estadística & datos numéricos , Preescolar , Erradicación de la Enfermedad , Humanos , Lactante , Sarampión/prevención & control , Nepal , Evaluación de Programas y Proyectos de Salud , Rubéola (Sarampión Alemán)/prevención & control
9.
MMWR Morb Mortal Wkly Rep ; 65(17): 438-42, 2016 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-27148917

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad/organización & administración , Salud Global , Laboratorios/organización & administración , Sarampión/prevención & control , Rubéola (Sarampión Alemán)/prevención & control , Objetivos , Humanos , Organización Mundial de la Salud
10.
MMWR Morb Mortal Wkly Rep ; 65(8): 206-10, 2016 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-26937619

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Sarampión/epidemiología , Sarampión/prevención & control , Vigilancia de la Población , Humanos , Programas de Inmunización , Esquemas de Inmunización , Incidencia , Lactante , Vacuna Antisarampión/administración & dosificación , Virus del Sarampión/aislamiento & purificación , Nepal/epidemiología , Vacunación/estadística & datos numéricos
11.
PLoS One ; 11(3): e0149160, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26962867

RESUMEN

BACKGROUND: The burden of Congenital Rubella Syndrome (CRS) is typically underestimated in routine surveillance. Updated estimates are needed following the recent WHO position paper on rubella and recent GAVI initiatives, funding rubella vaccination in eligible countries. Previous estimates considered the year 1996 and only 78 (developing) countries. METHODS: We reviewed the literature to identify rubella seroprevalence studies conducted before countries introduced rubella-containing vaccination (RCV). These data and the estimated vaccination coverage in the routine schedule and mass campaigns were incorporated in mathematical models to estimate the CRS incidence in 1996 and 2000-2010 for each country, region and globally. RESULTS: The estimated CRS decreased in the three regions (Americas, Europe and Eastern Mediterranean) which had introduced widespread RCV by 2010, reaching <2 per 100,000 live births (the Americas and Europe) and 25 (95% CI 4-61) per 100,000 live births (the Eastern Mediterranean). The estimated incidence in 2010 ranged from 90 (95% CI: 46-195) in the Western Pacific, excluding China, to 116 (95% CI: 56-235) and 121 (95% CI: 31-238) per 100,000 live births in Africa and SE Asia respectively. Highest numbers of cases were predicted in Africa (39,000, 95% CI: 18,000-80,000) and SE Asia (49,000, 95% CI: 11,000-97,000). In 2010, 105,000 (95% CI: 54,000-158,000) CRS cases were estimated globally, compared to 119,000 (95% CI: 72,000-169,000) in 1996. CONCLUSIONS: Whilst falling dramatically in the Americas, Europe and the Eastern Mediterranean after vaccination, the estimated CRS incidence remains high elsewhere. Well-conducted seroprevalence studies can help to improve the reliability of these estimates and monitor the impact of rubella vaccination.


Asunto(s)
Costo de Enfermedad , Inmunización , Internacionalidad , Síndrome de Rubéola Congénita/epidemiología , Adolescente , Adulto , Factores de Edad , Femenino , Geografía , Humanos , Incidencia , Nacimiento Vivo , Modelos Biológicos , Estudios Seroepidemiológicos , Adulto Joven
12.
MMWR Morb Mortal Wkly Rep ; 64(44): 1246-51, 2015 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-26562349

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Salud Global/estadística & datos numéricos , Sarampión/prevención & control , Adolescente , Adulto , Niño , Preescolar , Humanos , Incidencia , Lactante , Sarampión/epidemiología , Vacuna Antisarampión/administración & dosificación , Persona de Mediana Edad , Mortalidad/tendencias , Adulto Joven
13.
MMWR Morb Mortal Wkly Rep ; 64(37): 1052-5, 2015 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-26401958

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Salud Global/estadística & datos numéricos , Vigilancia de la Población , Síndrome de Rubéola Congénita/prevención & control , Rubéola (Sarampión Alemán)/prevención & control , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Programas de Inmunización , Esquemas de Inmunización , Lactante , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/prevención & control , Rubéola (Sarampión Alemán)/epidemiología , Síndrome de Rubéola Congénita/epidemiología , Vacuna contra la Rubéola/uso terapéutico , Adulto Joven
14.
Vaccine ; 33(17): 2050-5, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25769207

RESUMEN

BACKGROUND: To develop a successful model for accelerating measles elimination in poor areas of China, we initiated a seven-year project in Guizhou, one of the poorest provinces, with reported highest measles incidence of 360 per million population in 2002. METHODS: Project strategies consisted of strengthening routine immunization services, enforcement of school entry immunization requirements at kindergarten and school, conducting supplemental measles immunization activities (SIAs), and enhancing measles surveillance. We measured coverage of measles containing vaccines (MCV) by administrative reporting and population-based sample surveys, systematic random sampling surveys, and convenience sampling surveys for routine immunization services, school entry immunization, and SIAs respectively. We measured impact using surveillance based measles incidence. RESULTS: Routine immunization coverage of the 1st dose of MCV (MCV1) increased from 82% to 93%, while 2nd dose of MCV (MCV2) coverage increased from 78% to 91%. Enforcement of school entry immunization requirements led to an increase in MCV2 coverage from 36% on primary school entry in 2004 to 93% in 2009. Province-wide SIAs achieved coverage greater than 90%. The reported annual incidence of measles dropped from 200 to 300 per million in 2003 to 6 per million in 2009, and sustained at 0.9-2.2 per million in 2010-2013. CONCLUSIONS: This project found that a package of strategies including periodic SIAs, strengthened routine immunization, and enforcing school entry immunization requirements, was an effective approach toward achieving and sustaining measles elimination in less-developed area of China.


Asunto(s)
Erradicación de la Enfermedad/métodos , Programas de Inmunización/estadística & datos numéricos , Programas de Inmunización/normas , Vacuna Antisarampión , Sarampión/prevención & control , Niño , Preescolar , China/epidemiología , Erradicación de la Enfermedad/normas , Femenino , Humanos , Incidencia , Masculino , Vacuna Antisarampión/administración & dosificación , Vigilancia de la Población , Población Rural , Encuestas y Cuestionarios , Factores de Tiempo
16.
Lancet ; 385(9984): 2297-307, 2015 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-25576992

RESUMEN

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.


Asunto(s)
Rubéola (Sarampión Alemán)/prevención & control , Vacunas Virales/uso terapéutico , Afinidad de Anticuerpos , Salud Global , Humanos , Inmunidad Innata , Inmunogenética , Polimorfismo Genético , Vigilancia de la Población , Rubéola (Sarampión Alemán)/epidemiología , Rubéola (Sarampión Alemán)/genética , Rubéola (Sarampión Alemán)/inmunología , Síndrome de Rubéola Congénita/diagnóstico , Síndrome de Rubéola Congénita/epidemiología , Síndrome de Rubéola Congénita/prevención & control , Vacunas Virales/inmunología
17.
Vaccine ; 32(51): 6880-6883, 2014 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-25444814

RESUMEN

Tremendous progress has been made globally to reduce the contribution of measles to the burden of childhood deaths and measles cases have dramatically decreased with increased two dose measles-containing vaccine coverage. As a result the Global Vaccine Action Plan, endorsed by the World Health Assembly, has targeted measles elimination in at least five of the six World Health Organisation Regions by 2020. This is an ambitious goal, since measles control requires the highest immunisation coverage of any vaccine preventable disease, which means that the health system must be able to reach every community. Further, while measles remains endemic in any country, importations will result in local transmission and outbreaks in countries and Regions that have interrupted local endemic measles circulation. One of the lines of evidence that countries and Regions must address to confirm measles elimination is a detailed description of measles epidemiology over an extended period. This information is incredibly valuable as predictable epidemiological patterns emerge as measles elimination is approached and achieved. These critical features, including the source, size and duration of outbreaks, the seasonality and age-distribution of cases, genotyping pointers and effective reproduction rate estimates, are discussed with illustrative examples from the Region of the Americas, which eliminated measles in 2002, and the Western Pacific Region, which has established a Regional Verification Commission to review progress towards elimination in all member countries.


Asunto(s)
Control de Enfermedades Transmisibles/métodos , Erradicación de la Enfermedad , Vacuna Antisarampión/administración & dosificación , Sarampión/epidemiología , Sarampión/prevención & control , Control de Enfermedades Transmisibles/organización & administración , Humanos
18.
MMWR Morb Mortal Wkly Rep ; 63(45): 1034-8, 2014 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-25393223

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Salud Global/estadística & datos numéricos , Sarampión/prevención & control , Adolescente , Niño , Preescolar , Humanos , Incidencia , Lactante , Sarampión/epidemiología , Vacuna Antisarampión/administración & dosificación , Mortalidad/tendencias , Adulto Joven
19.
MMWR Morb Mortal Wkly Rep ; 63(23): 511-5, 2014 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-24918486

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Sarampión/prevención & control , Vigilancia de la Población , Adolescente , África del Norte/epidemiología , Niño , Preescolar , Genotipo , Humanos , Programas de Inmunización , Incidencia , Lactante , Sarampión/epidemiología , Vacuna Antisarampión/administración & dosificación , Virus del Sarampión/genética , Virus del Sarampión/aislamiento & purificación , Medio Oriente/epidemiología , Adulto Joven
20.
MMWR Morb Mortal Wkly Rep ; 63(13): 285-91, 2014 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-24699765

RESUMEN

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.


Asunto(s)
Erradicación de la Enfermedad , Sarampión/epidemiología , Sarampión/prevención & control , Vigilancia de la Población , África/epidemiología , Genotipo , Humanos , Programas de Inmunización , Incidencia , Vacuna Antisarampión/administración & dosificación , Virus del Sarampión/genética , Vacunación/estadística & datos numéricos
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