Progress in vaccination towards hepatitis B control and elimination in the Region of the Americas.

BACKGROUND: Over recent decades, the Region of the Americas has made significant progress towards hepatitis B elimination. We summarize the countries/territories' efforts in introducing and implementing hepatitis B (HB) vaccination and in evaluating its impact on HB virus seroprevalence. METHODS: We collected information about HB vaccination schedules, coverage estimates, and year of vaccine introduction from countries/territories reporting to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF Joint Reporting Form on Immunization. We obtained additional information regarding countries/territories vaccination recommendations and strategies through communications with Expanded Program on Immunization (EPI) managers and national immunization survey reports. We identified vaccine impact studies conducted and published in the Americas. RESULTS: As of October 2016, all 51 countries/territories have included infant HB vaccination in their official immunization schedule. Twenty countries, whose populations represent over 90% of the Region's births, have included nationwide newborn HB vaccination. We estimated at 89% and 75%, the regional three-dose series and the birth dose HB vaccination coverage, respectively, for 2015. The impact evaluations of infant HB immunization programs in the Region have shown substantial reductions in HB surface antigen (HBsAg) seroprevalence. CONCLUSION: The achievements of vaccination programs in the Americas suggest that the elimination of perinatal and early childhood HB transmission could be feasible in the short-term. Moreover, the data gathered indicate that the Region may have already achieved the 2020 WHO goal for HB control.

Progress towards a comprehensive approach to maternal and neonatal immunization in the Americas.

Maternal and neonatal immunization (MNI) is a core component of the new immunization model in the Americas, which transitioned from immunization of children to that of the entire family. Immunization during pregnancy protects the mother and the fetus by providing the neonate with maternal antibodies against disease. It has the potential to impact early childhood morbidity and mortality, and thus MNI has gained visibility and priority on the global health agenda. The Region of the Americas is a leader in MNI, as seen by its elimination of congenital rubella syndrome in 2015 and the progress made toward neonatal tetanus elimination. In the Americas, 31 countries currently target pregnant women for influenza vaccination; and 21 countries-over 90% of the Region's birth cohort-have nationwide newborn hepatitis B vaccination. This paper describes the status of MNI in the Americas and identifies gaps in the evidence, obstacles to optimal implementation, and opportunities for future improvements. Catalysts for MNI in the Region have been political commitment, endorsement by scientific societies, an established "culture of vaccination," widespread access to antenatal care, and context-specific communications; however, universal and equitable access for pregnant women and their newborns continues to be a formidable challenge, and additional vaccine safety and effectiveness evidence is needed. Continued efforts to integrate MNI with maternal and child health services will be critical to furthering the MNI platform as well.

La inmunización materna y neonatal es un componente central del nuevo modelo de inmunización en la Región de las Américas, que pasó de la inmunización infantil a la de toda la familia. La inmunización durante el embarazo protege a la madre y el feto dando al recién nacido los anticuerpos maternos contra las enfermedades. Tiene el potencial de repercutir en la morbilidad y la mortalidad en la primera infancia, por lo que la inmunización materna y neonatal ha adquirido visibilidad y prioridad en la agenda mundial de salud.La Región de las Américas ocupa una posición de liderazgo en materia de inmunización materna y neonatal, como lo demuestra la eliminación del síndrome de rubéola congénita en el 2015 y los avances logrados para la eliminación del tétanos neonatal. Actualmente en 31 países de la Región se da prioridad a las embarazadas para que reciban vacunación antigripal y en 21 países ­más de 90% de la cohorte de nacimiento de la Región­ se incluye la vacunación de los recién nacidos contra la hepatitis B a nivel nacional.En este documento se describe la situación de la inmunización materna y neonatal en la Región de las Américas y se señalan las lagunas en la evidencia, los obstáculos a la implementación óptima y las oportunidades para las mejoras futuras. Los catalizadores de la inmunización materna y neonatal en la Región han sido el compromiso político, el aval de las sociedades científicas, una "cultura de vacunación" establecida, el acceso generalizado a la atención prenatal y las comunicaciones específicas para cada contexto; sin embargo, el acceso universal y equitativo de las embarazadas y los recién nacidos sigue siendo un reto enorme y se necesitan más datos científicos sobre la seguridad y efectividad de las vacunas. La continuación de los esfuerzos para integrar la inmunización materna y neonatal en los servicios de salud maternoinfantil será fundamental para promover también la plataforma a favor de esta inmunización.

A imunização materna e neonatal é peça fundamental do novo modelo de imunização nas Américas, com a transição da vacinação de crianças à vacinação de toda a família. A vacinação da gestante protege a mãe e o feto ao proporcionar ao recém-nascido anticorpos maternos contra doenças. A imunização materna e neonatal possivelmente repercute na primeira infância reduzindo a morbidade e a mortalidade e, portanto, ganhou visibilidade sendo considerada prioritária na agenda global de saúde.A Região das Américas é líder em imunização materna e neonatal, tendo alcançado a eliminação da síndrome da rubéola congênita em 2015 e avançado para a eliminação do tétano neonatal. Existem atualmente programas de vacinação contra influenza para gestantes em 31 países e programas nacionais de vacinação contra hepatite B para recém-nascidos em 21 países (com uma cobertura superior a 90% da coorte de nascidos vivos na Região).Este artigo apresenta um panorama da imunização materna e neonatal nas Américas, destaca as lacunas nas evidências científicas e os obstáculos à implementação ideal dos programas de vacinação e aponta oportunidades futuras para melhorias. Entre os fatores responsáveis pelo incentivo à imunização materna e neonatal na Região estão o compromisso político, o endosso das sociedades científicas, uma "cultura de vacinação" estabelecida, o amplo acesso à assistência pré-natal e a comunicação contextualizada. Porém, o acesso universal e equitativo das gestantes e seus recémnascidos à vacinação é ainda um grande desafio e se fazem necessárias mais evidências sobre a segurança e a efetividade das vacinas. Além disso, é imprescindível o empenho contínuo para integrar a imunização materna e neonatal aos serviços de saúde materno-infantil e seguir promovendo a plataforma de imunização materna e neonatal.

The evolution of Vaccination Week in the Americas.

This report covers the background and evolution of Vaccination Week in the Americas (VWA), an initiative that started as a coordinated response to a 2002 measles outbreak in Colombia and Venezuela, and evolved into the model for other regions and World Immunization Week (WIW). VWA focuses on the work of national immunization programs, with special efforts to reach the unreached. This paper offers examples of how countries have leveraged VWA to implement a diverse array of vaccination activities, strengthening overall health services by integrating with other preventive health interventions, and bolstering "Pan-Americanism" and health diplomacy. The opportunities offered by this global initiative were clearly demonstrated in April 2016 when the successful global switch from the trivalent oral polio vaccine to the bivalent vaccine was synchronized with WIW. Going forward, VWA and WIW can help close the gaps in access to immunization and other health services, contributing to achieve universal health coverage.

Este informe incluye los antecedentes y la evolución de la Semana de Vacunación en las Américas, una iniciativa que comenzó como una respuesta coordinada a un brote de sarampión en Colombia y Venezuela en el 2002, y evolucionó hasta convertirse en modelo para otras regiones y para la Semana Mundial de la Inmunización.La Semana de Vacunación en las Américas se centra en el trabajo de los programas nacionales de inmunización, con esfuerzos especiales para llegar a las personas que todavía no estén cubiertas. En el presente trabajo se dan ejemplos de cómo los países han aprovechado la Semana de Vacunación para realizar diversas actividades relacionadas con la vacunación, fortalecer los servicios de salud en general mediante la integración con otras intervenciones preventivas y fomentar el "panamericanismo" y la diplomacia en torno a la salud.Las oportunidades que ofrece esta iniciativa mundial quedaron claramente evidenciadas en abril del 2016 con el éxito obtenido en la sustitución de la vacuna oral trivalente contra la poliomielitis por la vacuna bivalente, sincronizada con la Semana Mundial de la Inmunización. En el futuro, la Semana de Vacunación en las Américas y la Semana Mundial de Inmunización pueden ayudar a subsanar la brecha en el acceso a la inmunización y otros servicios de salud, y contribuir a alcanzar la cobertura universal de salud.

Este artigo narra os antecedentes e a evolução da Semana de Vacinação nas Américas (SVA), uma iniciativa que nasceu da resposta coordenada ao surto de sarampo na Colômbia e na Venezuela em 2002 e evoluiu como um modelo para as outras regiões e para a Semana Mundial da Imunização.A SVA põe ênfase no trabalho dos programas nacionais de vacinação e, principalmente, nos esforços para sealcançar quem ainda está inalcançado. São ilustrados exemplos de como os países têm aproveitado a SVA para implementar várias atividades de vacinação, fortalecendo os serviços de saúde em geral ao integrá-la a outras intervenções preventivas e reforçando o pan-americanismo e a diplomacia da saúde.As oportunidades criadas por esta iniciativa global ficaram bem evidentes em abril de 2016 com a bem-sucedida transição em nível mundial da vacina oral contra poliomielite trivalente à bivalente, em sincronia com a Semana Mundial da Imunização. Prosseguindo adiante, a SVA e a Semana Mundial da Imunização podem contribuir para sanar as lacunas no acesso à imunização e a outros serviços de saúde e alcançar a cobertura universal de saúde.

Vaccination Week in the Americas, 2011: an opportunity to assess the routine vaccination program in the Bolivarian Republic of Venezuela.

BACKGROUND: Vaccination Week in the Americas (VWA) is an annual initiative in countries and territories of the Americas every April to highlight the work of national expanded programs on immunization (EPI) and increase access to vaccination services for high-risk population groups. In 2011, as part of VWA, Venezuela targeted children aged less than 6 years in 25 priority border municipalities using social mobilization to increase institution-based vaccination. Implementation of social communication activities was decentralized to the local level. We conducted a survey in one border municipality of Venezuela to evaluate the outcome of VWA 2011 and provide a snapshot of the overall performance of the routine EPI at that level. METHODS: We conducted a coverage survey, using stratified cluster sampling, in the Venezuelan municipality of Bolivar (bordering Colombia) in August 2011. We collected information for children aged <6 years through caregiver interviews and transcription of vaccination card data. We estimated each child's eligibility to receive a specific vaccine dose during VWA 2011 and whether or not they were actually vaccinated during VWA activities. We also estimated baseline vaccination coverage, timeliness and 95% confidence intervals (CI), and used chi-square tests to compare coverage across age cohorts, taking into account the sampling design. RESULTS: We surveyed 839 children from 698 households; 93% of children had a vaccination card. Among households surveyed, 216 (31%) caregivers reported having heard about a vaccination activity during April or May 2011. Of the 528 children eligible to receive a vaccine during VWA, 24% received at least one dose, while 13% received all doses due. Overall, baseline coverage with routine vaccines, as measured by the survey, was >85%, with a few exceptions. CONCLUSION: Low levels of VWA awareness among caregivers probably contributed to the limited vaccination of eligible children during the VWA activities in Bolivar in 2011. However, vaccine coverage for most EPI vaccines was high. Additionally, high vaccination card availability and high participation in VWA among those caregivers aware of it in 2011 suggest public trust in the EPI program in the municipality. Health authorities have used survey findings to inform changes to the routine EPI and better VWA implementation in subsequent years.

Pilot to evaluate the feasibility of measuring seasonal influenza vaccine effectiveness using surveillance platforms in Central-America, 2012.

BACKGROUND: Since 2004, the uptake of seasonal influenza vaccines in Latin America and the Caribbean has markedly increased. However, vaccine effectiveness (VE) is not routinely measured in the region. We assessed the feasibility of using routine surveillance data collected by sentinel hospitals to estimate influenza VE during 2012 against laboratory-confirmed influenza hospitalizations in Costa-Rica, El Salvador, Honduras and Panama. We explored the completeness of variables needed for VE estimation. METHODS: We conducted the pilot case-control study at 23 severe acute respiratory infections (SARI) surveillance hospitals. Participant inclusion criteria included children 6 months-11 years and adults ≥60 years targeted for vaccination and hospitalized for SARI during January-December 2012. We abstracted information needed to estimate target group specific VE (i.e., date of illness onset and specimen collection, preexisting medical conditions, 2012 and 2011 vaccination status and date, and pneumococcal vaccination status for children and adults) from SARI case-reports and for children ≤9 years, inquired about the number of annual vaccine doses given. A case was defined as an influenza virus positive by RT-PCR in a person with SARI, while controls were RT-PCR negative. We recruited 3 controls per case from the same age group and month of onset of symptoms. RESULTS: We identified 1,186 SARI case-patients (342 influenza cases; 849 influenza-negative controls), of which 994 (84 %) had all the information on key variables sought. In 893 (75 %) SARI case-patients, the vaccination status field was missing in the SARI case-report forms and had to be completed using national vaccination registers (36 %), vaccination cards (30 %), or other sources (34 %). After applying exclusion criteria for VE analyses, 541 (46 %) SARI case-patients with variables necessary for the group-specific VE analyses were selected (87 cases, 236 controls among children; 64 cases, 154 controls among older adults) and were insufficient to provide precise regional estimates (39 % for children and 25 % for adults of minimum sample size needed). CONCLUSIONS: Sentinel surveillance networks in middle income countries, such as some Latin American and Caribbean countries, could provide a simple and timely platform to estimate regional influenza VE annually provided SARI forms collect all necessary information.

Vaccination Week in the Americas: an opportunity to integrate other health services with immunization.

Vaccination Week in the Americas (VWA) is an initiative of the countries and territories of the Americas that works to advance equity and access to vaccination. The initiative focuses on reaching populations with limited access to regular health services and promotes solidarity among countries. As the Expanded Program on Immunization is one of the world's best-established health programs, integrating other interventions with immunization services has been highly promoted. Using data available from the Pan American Health Organization, we explored the extent of integration of other interventions with immunization in Latin American and Caribbean (LAC) countries as part of VWA. At least 14 countries or territories have integrated other interventions with immunization during VWA. The most common integrated intervention is vitamin A supplementation, followed by deworming. However, a variety of other interventions have been integrated, such as educational activities, supplementation with vitamins and minerals, and provision of health services. Data on coverage of integrated interventions are limited. Integration of other interventions with immunization in LAC countries is widespread, and its impact and lessons learned merit further examination.

Seasonal influenza vaccination policies in the 194 WHO Member States: The evolution of global influenza pandemic preparedness and the challenge of sustaining equitable vaccine access.

INTRODUCTION: As of 2018, 118 of 194 WHO Member States reported the presence of an influenza vaccination policy. Although influenza vaccination policies do not guarantee equitable access or ensure vaccination coverage, they are critical to establishing a coordinated influenza vaccination program, which can reduce morbidity and mortality associated with yearly influenza, especially in high-risk groups. Established programs can also provide a good foundation for pandemic preparedness and response. METHODS: We utilized EXCEL and STATA to evaluate changes to national seasonal influenza vaccination policies reported on the WHO/UNICEF Joint Reporting Forms on Immunization (JRF) in 2014 and 2018. To characterize countries with or without policies, we incorporated external data on World Bank income groupings, WHO regions, and immunization system strength (using 3 proxy indicators). RESULTS: From 2014 to 2018 there was a small net increase in national seasonal influenza vaccination policies from 114 (59%) to 118 (61%). There was an increase in policies targeting high-risk groups from 34 in 2014 (34 /114 policies, 29%) to 56 (56/118 policies, 47%) in 2018. Policies were consistently more frequent in high-income countries, in WHO Regions of the Americas (89% of countries) and Europe (89%), and in countries satisfying all three immunization system strength indicators. Low and low-middle income countries, representing 40% of the worlds' population, accounted for 52/61 (85%) of countries with no evidence of a policy in either year. CONCLUSION: Our results demonstrate that national influenza vaccination policies vary significantly by region, income, and immunization system strength, and are less common in lower-income countries. Barriers to establishing and maintaining policies should be further examined as part of international efforts to expand influenza vaccination policies globally. Next generation influenza vaccine development should work to address barriers to influenza vaccination policy adoption, such as cost, logistics for adult vaccination, country priorities, need for yearly vaccination, and variations in seasonality.

Adverse events associated with the use of recommended vaccines during pregnancy: An overview of systematic reviews.

INTRODUCTION: Maternal immunization is aimed at reducing morbidity and mortality in pregnant women and their newborns. Updated evidence synthesis of maternal-fetal outcomes is constantly needed to ensure that the risk-benefit of vaccination during pregnancy remains positive. METHODS: An overview of systematic reviews (OoSRs) was performed. We searched The Cochrane Library, MEDLINE and EMBASE for SRs including recommended vaccines for maternal immunization reporting the following: abortion, stillbirth, chorioamnionitis, congenital anomalies, microcephaly, neonatal death, neonatal infection, preterm birth (PTB), low birth weight (LBW), maternal death and small for gestational age (SGA) from 2010 to April 2019. Quality and overlap of SRs was assessed. RESULTS: Seventeen SRs were identified, eight of them included meta-analysis; quality was high in three SRs, moderate in six SRs, low in two SRs, and critically low in six SRs. Stillbirth and PTB were the most frequently reported outcomes by 15 and 13 SRs, respectively, followed by abortion (9 SRs), congenital anomalies (9 SRs), SGA (8 SRs), neonatal death (8 SRs), LBW (4 SRs), chorioamnionitis (3 SRs), maternal death (1 SR). SRs included mainly observational evidence for influenza and Tdap vaccines (11 SRs and 4 SRs, respectively); limited evidence was found for hepatitis (1 SR), yellow fever (1 SR), and meningococcal (1 SR) vaccines. Most of the SRs found no effect. Eight SRs found benefit/protection of influenza vaccine (for stillbirth, neonatal death, preterm birth, LBW), or Tdap vaccine (for preterm birth and SGA); one found a probable risk (chorioamnionitis/Tdap). The SRs for Hepatitis B, meningococcal and yellow fever vaccines were inconclusive. CONCLUSIONS: Definite risks were not identified for any vaccine and outcome; however better evidence is needed for all outcomes and vaccines. The available evidence in the SRs to support vaccine safety was based mainly on observational data. More RCTs with adequate reporting of maternal-fetal outcomes and larger high-quality observational studies are needed.

Enablers and barriers of maternal and neonatal immunization programs in Latin America.

BACKGROUND: The Region of the Americas has a long history of implementing maternal and neonatal immunization (MNI) programs. Our study aimed to understand the state of MNI policies, strategies and implementation practices in Latin America (LA). METHODS: Study conducted in 5 middle-income countries: Argentina, Brazil, Honduras, Mexico and Peru. The methods included a desk review, interviews with national stakeholders and health care providers, focus groups with pregnant women and observations in health facilities. Enablers and barriers were identified and categorized as individual, societal or related to the health system. RESULTS: All 5 participating countries had similar MNI policies and high access to antenatal care. Key enablers were the high acceptability of vaccination during pregnancy, high-level of political will and a national legal framework ensuring free access to vaccines. At the health system level, implementation was facilitated by the existence of immunization advisory committees, a pooled vaccine procurement mechanism, complementary vaccine delivery strategies, conditional cash transfer to users and performance incentives to health facilities. The main programmatic barriers were the lack of adequate MNI information; limited coordination between antenatal and immunization services; inadequate supply, resources and infrastructure; high staff turnover; insufficient training for health care providers; and weak monitoring and reporting systems. CONCLUSION: Middle-income countries in LA have successfully implemented MNI programs and several enablers were identified. To overcome remaining barriers, there is a need to focus on improving the "immunization journey" for pregnant women through providing more clear and timely information to users and providers; removing barriers to access; ensuring adequate supply, human resources and infrastructure; making the health service experience positive; and establishing integrated information systems that allow for monitoring the progress toward achieving MNI goals. Strengthening the MNI programs can also improve equitable access to health services and prepare for the introduction of future vaccines for pregnant women.

Expansion of seasonal influenza vaccination in the Americas.

BACKGROUND: Seasonal influenza is a viral disease whose annual epidemics are estimated to cause three to five million cases of severe illness and 250,000 to 500,000 deaths worldwide. Vaccination is the main strategy for primary prevention. METHODS: To assess the status of influenza vaccination in the Americas, influenza vaccination data reported to the Pan American Health Organization (PAHO) through 2008 were analyzed. RESULTS: Thirty-five countries and territories administered influenza vaccine in their public health sector, compared to 13 countries in 2004. Targeted risk groups varied. Sixteen countries reported coverage among older adults, ranging from 21% to 100%; coverage data were not available for most countries and targeted populations. Some tropical countries used the Northern Hemisphere vaccine formulation and others used the Southern Hemisphere vaccine formulation. In 2008, approximately 166.3 million doses of seasonal influenza vaccine were purchased in the Americas; 30 of 35 countries procured their vaccine through PAHO's Revolving Fund. CONCLUSION: Since 2004 there has been rapid uptake of seasonal influenza vaccine in the Americas. Challenges to fully implement influenza vaccination remain, including difficulties measuring coverage rates, variable vaccine uptake, and limited surveillance and effectiveness data to guide decisions regarding vaccine formulation and timing, especially in tropical countries.

Introduction of new vaccines for immunization in pregnancy - Programmatic, regulatory, safety and ethical considerations.

Immunizing pregnant women is a promising strategy to reduce infectious disease-related morbidity and mortality in pregnant women and their infants. Important pre-requisites for the successful introduction of new vaccines for immunization in pregnancy include political commitment and adequate financial resources: trained, committed and sufficient numbers of healthcare workers to deliver the vaccines; close integration of immunization programs with antenatal care and Maternal and Child Health services; adequate access to antenatal care by pregnant women in the country (especially in low and middle-income countries (LMIC)); and a high proportion of births occurring in health facilities (to ensure maternal and neonatal follow-up can be done). The framework needed to advance a vaccine program from product licensure to successful country-level implementation includes establishing and organizing evidence for anticipated vaccine program impact, developing supportive policies, and translating policies into local action. International and national coordination efforts, proactive planning from conception to implementation of the programs (including country-level policy making, planning, and implementation, regulatory guidance, pharmacovigilance) and country-specific and cultural factors must be taken into account during the vaccines introduction.

Seasonal influenza vaccine effectiveness against laboratory-confirmed influenza hospitalizations - Latin America, 2013.

BACKGROUND: Despite widespread utilization of influenza vaccines, effectiveness (VE) has not been routinely measured in Latin America. METHODS: We used a case test-negative control design to estimate trivalent inactivated influenza VE against laboratory-confirmed influenza among hospitalized children aged 6months-5years and adults aged ≥60years which are age-groups targeted for vaccination. We sought persons with severe acute respiratory infections (SARI), hospitalized at 71 sentinel hospitals in Argentina, Brazil, Chile, Colombia, Costa Rica, El Salvador, Honduras, Panama, and Paraguay during January-December 2013. Cases had an influenza virus infection confirmed by real-time reverse transcription PCR (rRT-PCR); controls had a negative rRT-PCR result for influenza viruses. We used a two-stage random effects model to estimate pooled VE per target age-group, adjusting for the month of illness onset, age and preexisting medical conditions. RESULTS: We identified 2620 SARI patients across sites: 246 influenza cases and 720 influenza-negative controls aged ≤5years and 448 cases and 1206 controls aged ≥60years. The most commonly identified subtype among participants (48%) was the influenza A(H1N1)pdm09 virus followed by influenza A(H3N2) (34%) and influenza B (18%) viruses. Among children, the adjusted VE of full vaccination (one dose for previously vaccinated or two if vaccine naïve) against any influenza virus SARI was 47% (95% confidence interval [CI]: 14-71%); VE was 58% (95% CI: 16-79%) against influenza A(H1N1)pdm09, and 65% (95% CI: -9; 89%) against influenza A(H3N2) viruses associated SARI. Crude VE of full vaccination against influenza B viruses associated SARI among children was 3% (95% CI: -150; 63). Among adults aged ≥60years, adjusted VE against any influenza SARI was 48% (95% CI: 34-60%); VE was 54% (95% CI: 37-69%) against influenza A(H1N1)pdm09, 43% (95% CI: 18-61%) against influenza A(H3N2) and 34% (95% CI: -4; 58%) against B viruses associated SARI. CONCLUSION: Influenza vaccine provided moderate protection against severe influenza illness among fully vaccinated young children and older adults, supporting current vaccination strategies.

Influenza vaccination in the Americas: Progress and challenges after the 2009 A(H1N1) influenza pandemic.

BACKGROUND: There has been considerable uptake of seasonal influenza vaccines in the Americas compared to other regions. We describe the current influenza vaccination target groups, recent progress in vaccine uptake and in generating evidence on influenza seasonality and vaccine effectiveness for immunization programs. We also discuss persistent challenges, 5 years after the A(H1N1) 2009 influenza pandemic. METHODS: We compiled and summarized data annually reported by countries to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF joint report form on immunization, information obtained through PAHO's Revolving Fund for Vaccine Procurement and communications with managers of national Expanded Programs on Immunization (EPI). RESULTS: Since 2008, 25 countries/territories in the Americas have introduced new target groups for vaccination or expanded the age ranges of existing target groups. As of 2014, 40 (89%) out of 45 countries/territories have policies established for seasonal influenza vaccination. Currently, 29 (64%) countries/territories target pregnant women for vaccination, the highest priority group according to WHO´s Stategic Advisory Group of Experts and PAHO/WHO's Technical Advisory Group on Vaccine-preventable Diseases, compared to only 7 (16%) in 2008. Among 23 countries reporting coverage data, on average, 75% of adults ≥60 years, 45% of children aged 6-23 months, 32% of children aged 5-2 years, 59% of pregnant women, 78% of healthcare workers, and 90% of individuals with chronic conditions were vaccinated during the 2013-14 Northern Hemisphere or 2014 Southern Hemisphere influenza vaccination activities. Difficulties however persist in the estimation of vaccination coverage, especially for pregnant women and persons with chronic conditions. Since 2007, 6 tropical countries have changed their vaccine formulation from the Northern to the Southern Hemisphere formulation and the timing of their campaigns to April-May following the review of national evidence. LAC countries have also established an official network dedicated to evaluating influenza vaccines effectiveness and impact. CONCLUSION: Following the A(H1N1)2009 influenza pandemic, countries of the Americas have continued their efforts to sustain or increase seasonal influenza vaccine uptake among high risk groups, especially among pregnant women. Countries also continued strengthening influenza surveillance, immunization platforms and information systems, indirectly improving preparedness for future pandemics. Influenza vaccination is particularly challenging compared to other vaccines included in EPI schedules, due to the need for annual, optimally timed vaccination, the wide spectrum of target groups, and the limitations of the available vaccines. Countries should continue to monitor influenza vaccination coverage, generate evidence for vaccination programs and implement social communication strategies addressing existing gaps.

Timing of influenza epidemics and vaccines in the American tropics, 2002-2008, 2011-2014.

BACKGROUND: Influenza-associated illness results in increased morbidity and mortality in the Americas. These effects can be mitigated with an appropriately chosen and timed influenza vaccination campaign. To provide guidance in choosing the most suitable vaccine formulation and timing of administration, it is necessary to understand the timing of influenza seasonal epidemics. OBJECTIVES: Our main objective was to determine whether influenza occurs in seasonal patterns in the American tropics and when these patterns occurred. METHODS: Publicly available, monthly seasonal influenza data from the Pan American Health Organization and WHO, from countries in the American tropics, were obtained during 2002-2008 and 2011-2014 (excluding unseasonal pandemic activity during 2009-2010). For each country, we calculated the monthly proportion of samples that tested positive for influenza. We applied the monthly proportion data to a logistic regression model for each country. RESULTS: We analyzed 2002-2008 and 2011-2014 influenza surveillance data from the American tropics and identified 13 (81%) of 16 countries with influenza epidemics that, on average, started during May and lasted 4 months. CONCLUSIONS: The majority of countries in the American tropics have seasonal epidemics that start in May. Officials in these countries should consider the impact of vaccinating persons during April with the Southern Hemisphere formulation.

Pandemic influenza vaccination: lessons learned from Latin America and the Caribbean.

In April 2009, the World Health Organization (WHO) reported the emergence of a new influenza (H1N1) virus which led to the first pandemic declaration of the 21st century. Most countries in Latin America and the Caribbean (LAC) had a national preparedness plan in place at this time; however, the vaccination component of such plans was largely undeveloped. Nevertheless, countries were able to capitalize on the infrastructure of their immunization programs and widespread experience utilizing the seasonal influenza vaccine to prepare rapidly, developing H1N1 vaccination plans targeting individuals with chronic disease, pregnant women and health care workers, among others. In LAC vaccine was acquired through three mechanisms: the Pan American Health Organization's Revolving Fund, direct manufacturer purchase, and WHO donations. Vaccine access was not equitable both in quantity of vaccine available and timeless of vaccine availability. As of December 2010, an estimated 145 million doses had been administered in LAC. Despite high regional coverage, there were large variations in coverage at the national level; pregnant women had the lowest coverage, despite their high risk for morbidity and mortality. The number of severe adverse events reported in LAC was similar to those expected with the seasonal influenza vaccine. Risk communication was one of the key challenges countries faced, mainly due to concerns and misinformation spread regarding vaccine safety. Countries and the international community need to learn from the experiences gained during H1N1 vaccination in order to be better prepared for the next pandemic.

Progress towards a comprehensive approach to maternal and neonatal immunization in the Americas

[ABSTRACT]. Maternal and neonatal immunization (MNI) is a core component of the new immunization model in the Americas, which transitioned from immunization of children to that of the entire family. Immunization during pregnancy protects the mother and the fetus by providing the neonate with maternal antibodies against disease. It has the potential to impact early childhood morbidity and mortality, and thus MNI has gained visibility and priority on the global health agenda. The Region of the Americas is a leader in MNI, as seen by its elimination of congenital rubella syndrome in 2015 and the progress made toward neonatal tetanus elimination. In the Americas, 31 countries currently target pregnant women for influenza vaccination; and 21 countries—over 90% of the Region’s birth cohort—have nationwide newborn hepatitis B vaccination. This paper describes the status of MNI in the Americas and identifies gaps in the evidence, obstacles to optimal implementation, and opportunities for future improvements. Catalysts for MNI in the Region have been political commitment, endorsement by scientific societies, an established “culture of vaccination,” widespread access to antenatal care, and context-specific communications; however, universal and equitable access for pregnant women and their newborns continues to be a formidable challenge, and additional vaccine safety and effectiveness evidence is needed. Continued efforts to integrate MNI with maternal and child health services will be critical to furthering the MNI platform as well.

[RESUMEN]. La inmunización materna y neonatal es un componente central del nuevo modelo de inmunización en la Región de las Américas, que pasó de la inmunización infantil a la de toda la familia. La inmunización durante el embarazo protege a la madre y el feto dando al recién nacido los anticuerpos maternos contra las enfermedades. Tiene el potencial de repercutir en la morbilidad y la mortalidad en la primera infancia, por lo que la inmunización materna y neonatal ha adquirido visibilidad y prioridad en la agenda mundial de salud. La Región de las Américas ocupa una posición de liderazgo en materia de inmunización materna y neonatal, como lo demuestra la eliminación del síndrome de rubéola congénita en el 2015 y los avances logrados para la eliminación del tétanos neonatal. Actualmente en 31 países de la Región se da prioridad a las embarazadas para que reciban vacunación antigripal y en 21 países —más de 90% de la cohorte de nacimiento de la Región— se incluye la vacunación de los recién nacidos contra la hepatitis B a nivel nacional. En este documento se describe la situación de la inmunización materna y neonatal en la Región de las Américas y se señalan las lagunas en la evidencia, los obstáculos a la implementación óptima y las oportunidades para las mejoras futuras. Los catalizadores de la inmunización materna y neonatal en la Región han sido el compromiso político, el aval de las sociedades científicas, una “cultura de vacunación” establecida, el acceso generalizado a la atención prenatal y las comunicaciones específicas para cada contexto; sin embargo, el acceso universal y equitativo de las embarazadas y los recién nacidos sigue siendo un reto enorme y se necesitan más datos científicos sobre la seguridad y efectividad de las vacunas. La continuación de los esfuerzos para integrar la inmunización materna y neonatal en los servicios de salud maternoinfantil será fundamental para promover también la plataforma a favor de esta inmunización.

[RESUMO]. A imunização materna e neonatal é peça fundamental do novo modelo de imunização nas Américas, com a transição da vacinação de crianças à vacinação de toda a família. A vacinação da gestante protege a mãe e o feto ao proporcionar ao recém-nascido anticorpos maternos contra doenças. A imunização materna e neonatal possivelmente repercute na primeira infância reduzindo a morbidade e a mortalidade e, portanto, ganhou visibilidade sendo considerada prioritária na agenda global de saúde. A Região das Américas é líder em imunização materna e neonatal, tendo alcançado a eliminação da síndrome da rubéola congênita em 2015 e avançado para a eliminação do tétano neonatal. Existem atualmente programas de vacinação contra influenza para gestantes em 31 países e programas nacionais de vacinação contra hepatite B para recém-nascidos em 21 países (com uma cobertura superior a 90% da coorte de nascidos vivos na Região). Este artigo apresenta um panorama da imunização materna e neonatal nas Américas, destaca as lacunas nas evidências científicas e os obstáculos à implementação ideal dos programas de vacinação e aponta oportunidades futuras para melhorias. Entre os fatores responsáveis pelo incentivo à imunização materna e neonatal na Região estão o compromisso político, o endosso das sociedades científicas, uma “cultura de vacinação” estabelecida, o amplo acesso à assistência pré-natal e a comunicação contextualizada. Porém, o acesso universal e equitativo das gestantes e seus recém- -nascidos à vacinação é ainda um grande desafio e se fazem necessárias mais evidências sobre a segurança e a efetividade das vacinas. Além disso, é imprescindível o empenho contínuo para integrar a imunização materna e neonatal aos serviços de saúde materno-infantil e seguir promovendo a plataforma de imunização materna e neonatal.

The evolution of Vaccination Week in the Americas

[ABSTRACT]. This report covers the background and evolution of Vaccination Week in the Americas (VWA), an initiative that started as a coordinated response to a 2002 measles outbreak in Colombia and Venezuela, and evolved into the model for other regions and World Immunization Week (WIW). VWA focuses on the work of national immunization programs, with special efforts to reach the unreached. This paper offers examples of how countries have leveraged VWA to implement a diverse array of vaccination activities, strengthening overall health services by integrating with other preventive health interventions, and bolstering “Pan-Americanism” and health diplomacy. The opportunities offered by this global initiative were clearly demonstrated in April 2016 when the successful global switch from the trivalent oral polio vaccine to the bivalent vaccine was synchronized with WIW. Going forward, VWA and WIW can help close the gaps in access to immunization and other health services, contributing to achieve universal health coverage.

[RESUMEN]. Este informe incluye los antecedentes y la evolución de la Semana de Vacunación en las Américas, una iniciativa que comenzó como una respuesta coordinada a un brote de sarampión en Colombia y Venezuela en el 2002, y evolucionó hasta convertirse en modelo para otras regiones y para la Semana Mundial de la Inmunización. La Semana de Vacunación en las Américas se centra en el trabajo de los programas nacionales de inmunización, con esfuerzos especiales para llegar a las personas que todavía no estén cubiertas. En el presente trabajo se dan ejemplos de cómo los países han aprovechado la Semana de Vacunación para realizar diversas actividades relacionadas con la vacunación, fortalecer los servicios de salud en general mediante la integración con otras intervenciones preventivas y fomentar el “panamericanismo” y la diplomacia en torno a la salud. Las oportunidades que ofrece esta iniciativa mundial quedaron claramente evidenciadas en abril del 2016 con el éxito obtenido en la sustitución de la vacuna oral trivalente contra la poliomielitis por la vacuna bivalente, sincronizada con la Semana Mundial de la Inmunización. En el futuro, la Semana de Vacunación en las Américas y la Semana Mundial de Inmunización pueden ayudar a subsanar la brecha en el acceso a la inmunización y otros servicios de salud, y contribuir a alcanzar la cobertura universal de salud.

[RESUMO]. Este artigo narra os antecedentes e a evolução da Semana de Vacinação nas Américas (SVA), uma iniciativa que nasceu da resposta coordenada ao surto de sarampo na Colômbia e na Venezuela em 2002 e evoluiu como um modelo para as outras regiões e para a Semana Mundial da Imunização. A SVA põe ênfase no trabalho dos programas nacionais de vacinação e, principalmente, nos esforços para se alcançar quem ainda está inalcançado. São ilustrados exemplos de como os países têm aproveitado a SVA para implementar várias atividades de vacinação, fortalecendo os serviços de saúde em geral ao integrá-la a outras intervenções preventivas e reforçando o pan-americanismo e a diplomacia da saúde. As oportunidades criadas por esta iniciativa global ficaram bem evidentes em abril de 2016 com a bem-sucedida transição em nível mundial da vacina oral contra poliomielite trivalente à bivalente, em sincronia com a Semana Mundial da Imunização. Prosseguindo adiante, a SVA e a Semana Mundial da Imunização podem contribuir para sanar as lacunas no acesso à imunização e a outros serviços de saúde e alcançar a cobertura universal de saúde.

Consideraciones para la vacunación en caso de una pandemia de influenza / Considerations for the vaccination in case of pandemic influenza

La influenza es una de las enfermedades infecciosas que resultan en una alta carga de enfermedad por las epidemias estacionales que produce cada año. También puede producir pandemias con alta disrupción social y pérdidas económicas. La pandemia de gripe española de 1918 ocasionó entre 20 y 40 millones de muertes a nivel mundial. Ante la inminencia de una pandemia producida probablemente por la cepa A/H5N1, la elaboración de los planes de preparación contra la pandemia de influenza debe ser una prioridad en todos los países. La vigilancia epidemiológica y la preparación de vacunas son imprescindibles para el control de la influenza y prevenir sus efectos devastadores. La producción de vacunas contra influenza estacional es muy limitada, actualmente es de 300 millones de dosis a nivel mundial y todo el ciclo de producción toma aproximadamente entre 6 y 9 meses después de la identificación de los virus circulantes. En caso de una pandemia se requerirá dos dosis de vacuna para proteger a cada individuo, por lo cual se estima que sólo un 14 por ciento de la población tendría acceso a una vacuna monovalente en los primeros meses de la pandemia. En el marco de los planes nacionales de preparación contra la pandemia, la vacunación de la población a mayor riesgo debe estar claramente definida antes de la crisis y no durante la misma. La vacunación en caso de pandemia es una de las intervenciones más efectivas para su control, sin embargo la disponibilidad de la vacuna pandémica será muy limitada durante la primera ola de la misma, especialmente para países que no son productores de vacunas