HPV vaccine implementation and monitoring in Latin America.

OBJECTIVE: To describe HPV vaccine program implementation, monitoring and evaluation experiences in Latin America. MATERIALS AND METHODS: We reviewed published articles in peer-reviewed journals and reports from government web- sites, as well as the PAHO/WHO/UNICEF Joint Reporting form and the ICO/IARC HPV Information Centre database. RESULTS: By December 2016, 13 countries/territories in Latin America (56%) have introduced HPV vaccines. The majority have done so in the past three years, targeting 10- 12 year old girls with a two dose schedule, through school programs. Vaccine coverage ranges from 30 to 87%. Safety monitoring is well established, but monitoring vaccine impact is not, and data are not available. CONCLUSIONS: . Although Latin America is the most advanced developing region with HPV vaccine introduction, systems for its monitoring are weak and there is a paucity of consistently available coverage data for this vaccine. Challenges remain to introduce HPV vaccines in several countries, to achieve high coverage, and to strengthen monitoring, evaluation and reporting.

OBJETIVO: Describir las experiencias con la implementación, monitoreo y evaluación de programas de vacunación contra VPH en América Latina. MATERIAL Y MÉTODOS: Revisamos datos publicados en revistas, informes gubernamentales, así como los informes de monitoreo de programas de inmuniza- ciones de la OPS/OMS/UNICEF y del centro de información del VPH del ICO/IARC. RESULTADOS: Hasta diciembre de 2016, 13 países/territorios en América Latina (56%) han in- troducido vacunas contra VPH. La mayoría lo han hecho en los últimos tres años, apuntando a niñas de 10 a 12 años con un calendario de dos dosis, a través de programas escolares. La cobertura de vacunas varía entre 30 y 87%. La vigilancia de la seguridad está bien establecida, pero el monitoreo del impacto de la vacuna no, y los datos no están disponibles. CONCLUSIONES: Aunque América Latina es la región en de- sarrollo más avanzada en la introducción de la vacuna contra VPH, los sistemas para su monitoreo son débiles y hay una escasez de datos de cobertura disponibles. Sigue habiendo desafíos para introducir vacunas contra VPH en varios países, para lograr una alta cobertura y para fortalecer el monitoreo, la evaluación y la presentación de informes.

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.

[Experience with development of tools to monitor vaccination coverage and preventive chemotherapy coverageExperiência do desenvolvimento de ferramentas para o monitoramento da cobertura vacinal e quimioprofilaxia]. / Experiencia del desarrollo de herramientas para el monitoreo de coberturas de vacunación y quimioterapia preventiva.

OBJETIVO: Describir la experiencia y las lecciones aprendidas en el desarrollo de herramientas para el monitoreo de las coberturas de vacunación y de quimioterapia preventiva en las Américas. MÉTODOS: Se compiló y revisó la documentación disponible en los programas regionales de inmunización integral de la familia y de las enfermedades infecciosas desatendidas de la Organización Panamericana de la Salud/Organización Mundial de la Salud producida durante el proceso de desarrollo de las herramientas entre 2012 y 2017 incluidos: búsqueda sistemática de literatura, reportes técnicos, informes de reuniones internas, reporte de la prueba piloto e informes y resultados de las evaluaciones de los talleres de entrenamiento en doce países de las Américas. La documentación se organizó, se extrajo la información más relevante sobre el desarrollo de las herramientas y se consensuaron las principales lecciones aprendidas en el proceso. RESULTADOS: El proceso facilitó la organización y sistematización de las herramientas aplicadas durante las últimas dos décadas en los programas de vacunación en las Américas para el análisis y monitoreo de las coberturas y su rápida adaptación para el monitoreo de las coberturas de la quimioterapia preventiva. Se integró un conjunto de herramientas cuya aplicación se define con un algoritmo de decisiones y pueden ser utilizadas por los países. CONCLUSIONES: Las lecciones aprendidas pueden aplicarse para desarrollos similares y para promover el trabajo interprogramático en salud pública. El trabajo integrado aceleró el desarrollo de herramientas útiles para los países.

OBJETIVO: Descrever a experiência e as lições aprendidas no desenvolvimento de ferramentas para o monitoramento da cobertura vacinal e quimioprofilaxia nas Américas. MÉTODOS: Foi coletada e revisada a documentação disponível nos programas regionais de imunização integral da família e doenças infecciosas negligenciadas da Organização Pan-Americana da Saúde/Organização Mundial da Saúde, produzida no processo de desenvolvimento de ferramentas entre 2012 e 2017. Os arquivos englobavam resultados de busca sistemática da literatura, relatórios técnicos, atas de reuniões internas, informe de teste-piloto e relatórios e resultados das avaliações dos seminários de capacitação em 12 países das Américas. A documentação foi organizada e foram extraídos os dados mais relevantes sobre o desenvolvimento das ferramentas. As principais lições aprendidas no processo foram decididas por consenso. RESULTADOS: O processo facilitou a organização e a sistematização das ferramentas empregadas nas últimas duas décadas nos programas de vacinação nas Américas para avaliação e monitoramento da cobertura vacinal e sua rápida adaptação para o monitoramento da cobertura da quimioprofilaxia. Foi integrado um conjunto de ferramentas cuja aplicação é definida com um algoritmo de decisões e que pode ser utilizado pelos países. CONCLUSÕES: As lições aprendidas podem ser aplicadas em processos semelhantes de desenvolvimento e para promover o trabalho interprogramático em saúde pública. O trabalho integrado acelerou o desenvolvimento de ferramentas úteis para os países.

Lessons learned from the development of a new methodology to assess missed opportunities for vaccination in Latin America and the Caribbean.

The Pan American Health Organization recently developed a practical guide for evaluating missed opportunities for vaccination among children aged <5 years. A missed opportunity occurs when an individual eligible for vaccination has contact with a health facility and does not receive a needed vaccine, despite having no contraindications. In this article, we discuss the strengths and limitations of this new methodology and present lessons learned from recent studies on undervaccination in Latin America. Our findings should be useful to countries embarking on assessing the magnitude and the causes of missed opportunities for vaccination children experience at health facilities.

Vaccine-associated paralytic poliomyelitis in the postelimination era in Latin America and the Caribbean, 1992-2011.

The Americas interrupted the transmission of poliovirus in 1991; most Latin American and Caribbean (LAC) countries rely on the oral polio vaccine (OPV) to maintain elimination. We estimated the risk of vaccine-associated paralytic polio (VAPP) in LAC for 1992-2011. VAPP cases were identified using LAC's acute flaccid paralysis (AFP) surveillance system. VAPP was defined as any AFP case with residual paralysis 60 days following onset that did not have a clear alternative etiology and with isolation of vaccine-strain poliovirus. Recipient VAPP cases were defined as those with paralysis onset 4-40 days following OPV; cases meeting these criteria but with unknown residual paralysis were added. Nonrecipient VAPP cases were defined as those in individuals with an unknown vaccination status, those in individuals who received 0 doses, or those with paralysis onset outside the 4-40-day interval. Of 40 926 AFP cases reported in LAC from 1992-2011, we identified 72 recipient and 119 nonrecipient VAPP cases. The estimated risk of recipient VAPP was 1 case per 3.15 million newborns (95% confidence interval [CI], 1 case per 2.56-4.10 million newborns), and the estimated overall risk was 1 case per 1.19 million newborns (95% CI, 1 case per 1.04-1.39 million newborns). In this multicountry VAPP analysis in a postelimination period, we found that the risk of VAPP in LAC was lower than previously estimated.

Intussusception risk and health benefits of rotavirus vaccination in Mexico and Brazil.

BACKGROUND: Because postlicensure surveillance determined that a previous rotavirus vaccine, RotaShield, caused intussusception in 1 of every 10,000 recipients, we assessed the association of the new monovalent rotavirus vaccine (RV1) with intussusception after routine immunization of infants in Mexico and Brazil. METHODS: We used case-series and case-control methods to assess the association between RV1 and intussusception. Infants with intussusception were identified through active surveillance at 69 hospitals (16 in Mexico and 53 in Brazil), and age-matched infants from the same neighborhood were enrolled as controls. Vaccination dates were verified by a review of vaccination cards or clinic records. RESULTS: We enrolled 615 case patients (285 in Mexico and 330 in Brazil) and 2050 controls. An increased risk of intussusception 1 to 7 days after the first dose of RV1 was identified among infants in Mexico with the use of both the case-series method (incidence ratio, 5.3; 95% confidence interval [CI], 3.0 to 9.3) and the case-control method (odds ratio, 5.8; 95% CI, 2.6 to 13.0). No significant risk was found after the first dose among infants in Brazil, but an increased risk, albeit smaller than that seen after the first dose in Mexico--an increase by a factor of 1.9 to 2.6 - was seen 1 to 7 days after the second dose. A combined annual excess of 96 cases of intussusception in Mexico (approximately 1 per 51,000 infants) and in Brazil (approximately 1 per 68,000 infants) and of 5 deaths due to intussusception was attributable to RV1. However, RV1 prevented approximately 80,000 hospitalizations and 1300 deaths from diarrhea each year in these two countries. CONCLUSIONS: RV1 was associated with a short-term risk of intussusception in approximately 1 of every 51,000 to 68,000 vaccinated infants. The absolute number of deaths and hospitalizations averted because of vaccination far exceeded the number of intussusception cases that may have been associated with vaccination. (Funded in part by the GAVI Alliance and the U.S. Department of Health and Human Services.).

Electronic immunization registries in Latin America: progress and lessons learned.

Most of the current vaccination coverage monitoring in Latin America relies on aggregated data. Improved monitoring has been shown to result in better coverage. Taking advantage of current information and communication technologies, the use of electronic immunization registries (EIRs) can facilitate coverage monitoring in terms of particularity (at the level of the individual), timeliness, and accuracy. Countries in Latin America are rapidly developing and implementing national EIRs to improve the monitoring of immunization coverage. These countries are using a variety of approaches toward system conception and development; integration with larger health information systems; different modalities for data collection, entry, and transmission; and other key features. Some countries are exploring linkages with mHealth (mobile health) for data collection and for automated recall/reminders. Evaluating EIRs and sharing experiences are important to streamlining and improving national EIR development, implementation, and use, and to ensuring its sustainability.

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.

Measles and rubella elimination initiatives in the Americas: lessons learned and best practices.

Countries in the World Health Organization Region of the Americas successfully interrupted endemic measles virus transmission 8 years after setting a regional measles elimination goal and have sustained this achievement since 2002. The vast experience from the region clearly demonstrates that measles elimination can be accomplished and maintained over time. This brief report summarizes the lessons learned and the best practices that evolved in the Americas during 3 measles elimination phases (ie, preelimination, elimination, and postelimination phases), as well as the contribution of rubella elimination to strengthening and maintaining measles elimination. The effective measures that have been implemented and adapted by the countries of the Americas to eliminate endemic measles and rubella will serve as an example to other countries and regions embarking on this endeavor.

Elimination of rubella and congenital rubella syndrome in the Americas.

In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for rubella and congenital rubella syndrome (CRS) elimination in the Americas by the year 2010. To accomplish this goal, PAHO advanced a rubella and CRS elimination strategy including introduction of rubella-containing vaccines into routine vaccination programs accompanied by high immunization coverage, interruption of rubella transmission through mass vaccination of adolescents and adults, and strengthened surveillance for rubella and CRS. The rubella elimination strategies were aligned with the successful measles elimination strategies. By the end of 2009, all countries routinely vaccinated children against rubella, an estimated 450 million people had been vaccinated against measles and rubella in supplementary immunization activities, and rubella transmission had been interrupted. This article describes how the region eliminated rubella and CRS.

Rubella vaccination of unknowingly pregnant women during mass campaigns for rubella and congenital rubella syndrome elimination, the Americas 2001-2008.

BACKGROUND: Due to the significant teratogenicity of rubella virus and the use of a live-attentuated vaccine, pregnancy is a contraindication of receipt of rubella vaccine (RCV). Data collected from several countries that have observed susceptible women who had received RCV during pregnancy documented that no infant with congenital rubella syndrome (CRS) has been born, so the risk is theoretical. As part of the regional initiative to eliminate rubella and CRS in the Americas, one of the key strategies was the vaccination of women of childbearing age. The implementation of mass vaccination campaigns targeting women of childbearing age in Argentina, Brazil, Costa Rica, Ecuador, El Salvador, and Paraguay provided an opportunity to further increase the body of knowledge on the safety of rubella vaccine if an unknowingly pregnant woman is vaccinated in early pregnancy. METHODS: Using a standard protocol, women who were unknowingly pregnant or become pregnant ≤ 30 days after receiving RCV were evaluated to determine immunity status (eg, susceptible, immune, and unknown) at the time of vaccination. Susceptible pregnant women were observed to determine the outcome of the pregnancy. For pregnancies that resulted in live births, serum samples were obtained from the newborn for rubella immunoglobulin (Ig) M antibody testing. If the newborn's serum sample was IgM positive, the infant was evaluated for manifestations of CRS. RESULTS: During the period 2001-2008, 48748253 women of childbearing age were vaccinated in the region of the Americas, 39542253 (81%) of whom were vaccinated in the 6 selected countries. Of these women, 30139 (0.07%) were pregnant or became pregnant ≤1 month after receiving vaccine and were followed up. On the basis of serological evaluation, 2894 (10%) women were classified as susceptible at the time of vaccination; of their pregnancies, 1980 (90%) resulted in a live birth. Sera from 70 (3.5%) of these infants were rubella IgM antibody positive, but none of the infants had features of CRS as a result of rubella vaccination. The maximum theoretical risk for CRS following rubella vaccination of susceptible pregnant women was 0.2%. Conclusions. The results of these studies from 6 select countries provides additional evidence showing an absence of risk of CRS associated with administering rubella vaccine shortly before or during pregnancy.

Considerations for oral cholera vaccine use during outbreak after earthquake in Haiti, 2010-2011.

Oral cholera vaccines (OCVs) have been recommended in cholera-endemic settings and preemptively during outbreaks and complex emergencies. However, experience and guidelines for reactive use after an outbreak has started are limited. In 2010, after over a century without epidemic cholera, an outbreak was reported in Haiti after an earthquake. As intensive nonvaccine cholera control measures were initiated, the feasibility of OCV use was considered. We reviewed OCV characteristics and recommendations for their use and assessed global vaccine availability and capacity to implement a vaccination campaign. Real-time modeling was conducted to estimate vaccine impact. Ultimately, cholera vaccination was not implemented because of limited vaccine availability, complex logistical and operational challenges of a multidose regimen, and obstacles to conducting a campaign in a setting with population displacement and civil unrest. Use of OCVs is an option for cholera control; guidelines for their appropriate use in epidemic and emergency settings are urgently needed.

Guillain-Barré syndrome in children aged <15 years in Latin America and the Caribbean: baseline rates in the context of the influenza A (H1N1) pandemic.

In light of the influenza A (H1N1) pandemic, the Strategic Advisory Group of Experts on Immunization of the World Health Organization requested that the acute flaccid paralysis surveillance system of Latin American and the Caribbean be used to establish Guillain-Barré syndrome incidence rates. An analysis was conducted of 10,486 acute flaccid paralysis cases diagnosed as Guillain-Barré syndrome from 2000 through 2008 in children aged <15 years in Latin American and the Caribbean countries and territories. The average incidence was 0.82 cases per 100,000 children aged <15 years (range, 0.72-0.90 cases per 100,000 children), with significant differences between northern and southern countries (1.08 vs 0.57 cases per 100,000 children). The acute flaccid paralysis surveillance system represents a useful means of monitoring Guillain-Barré syndrome during the pandemic.

Monitoring progress of maternal and neonatal immunization in Latin America and the Caribbean.

INTRODUCTION: The Americas committed to strengthening maternal and neonatal immunization (MNI) through the Pan American Health Organization (PAHO) Regional Immunization Action Plan (RIAP) 2016-20. We describe the progress toward RIAP MNI-related targets and those related to improvement of data quality and information systems; analyze national MNI policies and vaccination coverages; and identify enablers and challenges of monitoring and reporting MNI vaccination coverage in Latin America and the Caribbean (LAC). METHODOLOGY: Descriptive study of national MNI policies, vaccination coverage, and information systems. Sources of information included PAHO-World Health Organization (WHO) / UNICEF Joint Reporting Forms on immunization (JRF) 2013-2019, and other reports. RESULTS: LAC has met two of three RIAP targets related to MNI (countries with universal hepatitis B birth dose introduction and elimination of maternal and neonatal tetanus) and is on track to meet the other (countries with vaccination of pregnant women). As of 2018, of the 49 countries and territories in LAC, 32 vaccinate pregnant women against influenza and 29 provide tetanus-containing vaccine. Twenty-five countries offer universal hepatitis B birth dose vaccine and 31 offer BCG vaccine. In 2018, regional influenza vaccine coverage among pregnant woman was 75%. Regional coverages for BCG and hepatitis B birth dose (<24 h) vaccines were 93% and 79%, respectively. Countries have exceeded RIAP targets related to the quality of vaccination coverage data and the establishment of electronic immunization registries (EIRs). Challenges in monitoring MNI coverage include estimation of denominators and difficulties disaggregating data by group (e.g., pregnant women versus other groups). CONCLUSION: Despite progress in improving MNI in LAC, countries must further strengthen immunization monitoring systems and data quality to better report vaccination coverage among pregnant women and newborns. EIR and MNI information systems must be integrated, such that countries can use accurate data to design more timely and effective vaccination strategies.

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.

Pneumococcal conjugate vaccine introduction in Latin America and the Caribbean: progress and lessons learned.

In Latin America and the Caribbean, pneumococcus has been estimated to cause 12,000-28,000 deaths, 182,000 hospitalizations, and 1.4 million clinic visits annually. Countries in the Americas have been among the first developing nations to introduce pneumococcal conjugate vaccines into their Expanded Programs on Immunization, with 34 countries and territories having introduced these vaccines as of September 2015. Lessons learned for successful vaccine introduction include the importance of coordination between political and technical decision makers, adjustments to the cold chain prior to vaccine introduction, and the need for detailed plans addressing the financial and technical sustainability of introduction. Though many questions on the Pneumococcal Conjugate Vaccine remain unanswered, the experience of the Americas suggests that the vaccines can be introduced quickly and effectively.

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.

Impact and Effectiveness of 10 and 13-Valent Pneumococcal Conjugate Vaccines on Hospitalization and Mortality in Children Aged Less than 5 Years in Latin American Countries: A Systematic Review.

BACKGROUND: Several Latin American and Caribbean (LAC) countries have introduced pneumococcal conjugate vaccine (PCV-10 or PCV-13) in their routine national immunization programs. OBJECTIVES: We aimed to summarize the evidence of PCV impact and effectiveness in children under 5 years old in the LAC Region. METHODS: We conducted a systematic review of the literature on impact or effectiveness of PCVs on deaths or hospitalizations due to invasive pneumococcal disease (IPD), pneumonia, meningitis and sepsis. We searched Medline, WoS, Lilacs, Scopus, Central and gray literature published in any language from 2009 to January 2016. We included studies addressing the outcomes of interest in children in the target age group, and with the following designs: randomized trials, cohort or case-control, interrupted time series with at least three data points before and after the intervention, and before-after studies. Screening of citations, data extraction, and risk of bias assessment were conducted in duplicate by independent reviewers, according to the study protocol registered on PROSPERO. Descriptive analysis of the effectiveness measurements and sensitivity analysis were conducted. Effectiveness is reported as 1-OR or 1-RR for case control or cohort/clinical trials, and as percent change of disease incidence rates for before-after studies. RESULTS: We identified 1,085 citations, 892 from databases and 193 from other sources. Of these, 22 were further analyzed. Studies were from Brazil, Chile, Uruguay, Argentina, Peru and Nicaragua. Effectiveness ranged from 8.8-37.8% for hospitalizations due to X-ray confirmed pneumonia, 7.4-20.6% for clinical pneumonia, and 13.3-87.7% for meningitis hospitalizations, and 56-83.3% for IPD hospitalization, varying by age, outcome definition, type of vaccine and study design. CONCLUSIONS: Available evidence to date indicates significant impact of both PCV-10 and PCV-13 in the outcomes studied, with no evidence of the superiority of one vaccine over the other on pneumonia, IPD or meningitis hospitalization reduction in children under 5 years old.