Systematic documentation of the introduction of COVID-19 vaccines in Latin America and the Caribbean.

Objective: To document the process of introducing COVID-19 vaccines in a selection of Latin American and Caribbean countries, including the lessons learned and the strengths and weaknesses, and similarities and differences among programs. Methods: This descriptive study is based on a systematic evaluation of the process of introducing COVID-19 vaccines in Argentina, Belize, Brazil, Costa Rica, Panama and Peru. Data were collected through a questionnaire distributed to key stakeholders. Six informants from each of the included countries participated in this study. The period of the study was from December 2021 through September 2022. Results: The main strengths reported by countries were health workers' commitment to delivering vaccinations, evidence-based decision-making, the development of plans for vaccine introduction, the participation of national immunization technical advisory groups, the availability of economic resources and positive actions from the respective Ministry of Health. The main challenges were the actions of antivaccination groups, problems with electronic immunization registries, a lack of vaccines, delays in the delivery of vaccines and the scarcity of health personnel at the local level. Conclusions: Commitment, the participation of multiple sectors, the availability of resources and preparedness planning were some of the many strengths shown by countries introducing COVID-19 vaccines. Weaknesses included third parties' interests, the lack of information systems and difficulty in accessing vaccines and vaccine services. There is a window of opportunity for countries to maintain the good practices that allowed for the processes' strengths and to assess the identified weaknesses to invigorate immunization programs and prepare for future health crises.

Development of a maturity assessment tool to evaluate and strengthen National Immunization Technical Advisory Groups (NITAGs).

As dozens of new National Immunization Technical Advisory Groups (NITAGs) were established worldwide in the past decade, and as existing NITAGs continued to play an important role in vaccine policy, global NITAG partners recognized a need for a standardized assessment tool to evaluate and strengthen their functions. This article describes the development of the NITAG Maturity Assessment Tool (NMAT), a stepwise evaluation tool that assesses NITAGs on seven key indicators of structure and process. A draft tool was developed through an iterative, consensus-based process with an expert working group before it was piloted with an economically and geographically diverse convenience sample of NITAGs. The final NMAT is a flexible tool that can be used by in-country or external evaluators to understand NITAG maturity, identify priorities for optimization, and measure the impact of strengthening efforts.

Estimated population-level impact of pneumococcal conjugate vaccines against all-cause pneumonia mortality among unvaccinated age groups in five Latin American countries.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) provide strong direct protection in children, while limited data are available on their indirect effect on mortality among older age groups. This multi-country study aimed to assess the population-level impact of pediatric PCVs on all-cause pneumonia mortality among ≥5 years of age, and invasive pneumococcal disease (IPD) cases in Chile. METHODS: Demographic and mortality data from Argentina, Brazil, Chile, Colombia, and Mexico were collected considering the ≥ 5-year-old population, from 2000-2019, with 1,795,789 deaths due to all-cause pneumonia. IPD cases in Chile were also evaluated. Time series models were employed to evaluate changes in all-cause pneumonia deaths during the post-vaccination period, with other causes of death used as synthetic controls for unrelated temporal trends. RESULTS: No significant change in death rates due to all-cause pneumonia was detected following PCV introduction among most age groups and countries. The proportion of IPD cases caused by vaccine serotypes decreased from 29% (2012) to 6% (2022) among ≥65 years in Chile. DISCUSSION: While an effect of PCV against pneumonia deaths (a broad clinical definition that may not be specific enough to measure indirect effects) was not detected, evidence of indirect PCV impact was observed among vaccine-type-specific IPD cases.

Systematic documentation of the introduction of COVID-19 vaccines in Latin America and the Caribbean / Documentación sistemática de la introducción de vacunas contra la COVID- 19 en América Latina y el Caribe / Documentação sistemática da introdução das vacinas contra a COVID-19 na América Latina e no Caribe

[ABSTRACT]. Objective. To document the process of introducing COVID-19 vaccines in a selection of Latin American and Caribbean countries, including the lessons learned and the strengths and weaknesses, and similarities and differences among programs. Methods. This descriptive study is based on a systematic evaluation of the process of introducing COVID-19 vaccines in Argentina, Belize, Brazil, Costa Rica, Panama and Peru. Data were collected through a questionnaire distributed to key stakeholders. Six informants from each of the included countries participated in this study. The period of the study was from December 2021 through September 2022. Results. The main strengths reported by countries were health workers’ commitment to delivering vaccinations, evidence-based decision-making, the development of plans for vaccine introduction, the participation of national immunization technical advisory groups, the availability of economic resources and positive actions from the respective Ministry of Health. The main challenges were the actions of antivaccination groups, problems with electronic immunization registries, a lack of vaccines, delays in the delivery of vaccines and the scarcity of health personnel at the local level. Conclusions. Commitment, the participation of multiple sectors, the availability of resources and preparedness planning were some of the many strengths shown by countries introducing COVID-19 vaccines. Weaknesses included third parties’ interests, the lack of information systems and difficulty in accessing vaccines and vac- cine services. There is a window of opportunity for countries to maintain the good practices that allowed for the processes’ strengths and to assess the identified weaknesses to invigorate immunization programs and prepare for future health crises.

[RESUMEN]. Objetivo. Documentar el proceso de introducción de las vacunas contra la COVID-19 en un algunos países de América Latina y el Caribe, incluidas las enseñanzas extraídas y sus puntos fuertes y débiles, así como las similitudes y diferencias entre los distintos programas. Métodos. Este estudio descriptivo se basa en una evaluación sistemática del proceso de introducción de las vacunas contra la COVID-19 en Argentina, Belice, Brasil, Costa Rica, Panamá y Perú. Los datos se recopilaron mediante un cuestionario distribuido a las principales partes interesadas. El estudio contó con la participación de un informante de cada uno de los seis países incluidos. El período de estudio fue de diciembre del 2021 a septiembre del 2022. Resultados. Los países indicaron como puntos fuertes principales el compromiso del personal de atención de salud con la vacunación, la toma de decisiones basada en la evidencia, la formulación de planes para la introducción de las vacunas, la participación de grupos técnicos asesores nacionales sobre inmunización, la disponibilidad de recursos económicos y las medidas favorables adoptadas por respectivos los Ministerios de Salud. Los retos más importantes fueron las acciones de los grupos contrarios a las vacunas, los problemas con los registros electrónicos de vacunación, la falta de vacunas, los retrasos en la entrega de vacunas y la escasez de personal de atención de salud a nivel local. Conclusiones. Se observó que el compromiso, la participación de múltiples sectores, la disponibilidad de recursos y la planificación de la preparación eran algunos de los puntos fuertes de los países que introdujeron las vacunas contra la COVID-19. Los puntos débiles fueron los intereses de terceros, la falta de sistemas de información y las dificultades para acceder a las vacunas y a los servicios de vacunación. Los países disponen ahora de una oportunidad para mantener las buenas prácticas que propiciaron los puntos fuertes de los procesos y evaluar los puntos débiles identificados a fin de fortalecer los programas de inmunización y prepararse para futuras crisis de salud.

[RESUMO]. Objetivo. Documentar o processo de introdução da vacina contra a COVID-19 em alguns países da América Latina e do Caribe, incluindo as lições aprendidas e os pontos fortes e fracos, bem como semelhanças e diferenças entre os programas. Métodos. Este estudo descritivo baseia-se em uma avaliação sistemática do processo de introdução das vacinas contra a COVID-19 na Argentina, em Belize, no Brasil, na Costa Rica, no Panamá e no Peru. Os dados foram coletados por meio de um questionário distribuído às principais partes interessadas. Seis informantes de cada um dos países incluídos participaram do estudo, que foi realizado entre dezembro de 2021 e setembro de 2022. Resultados. Os principais pontos fortes relatados pelos países foram o comprometimento dos profissionais de saúde com a vacinação, a tomada de decisões baseadas em evidências, o desenvolvimento de planos para a introdução de vacinas, a participação de grupos técnicos assessores nacionais sobre imunização, a disponibilidade de recursos econômicos e ações positivas dos respectivos ministérios da Saúde. Os principais desafios foram as ações de grupos antivacina, problemas com os registros eletrônicos de imunização, a falta de vacinas, atrasos na entrega das vacinas e a escassez de pessoal de saúde em nível local. Conclusões. O comprometimento, a participação de vários setores, a disponibilidade de recursos e o planejamento de preparação foram alguns dos muitos pontos fortes demonstrados pelos países ao introduzirem as vacinas contra a COVID-19. Entre os pontos fracos estavam os interesses de terceiros, a falta de sistemas de informação e a dificuldade de acesso às vacinas e aos serviços de vacinação. Há uma janela de oportunidade para que os países mantenham as boas práticas que viabilizaram os pontos fortes dos processos e avaliem os pontos fracos identificados a fim de revigorar os programas de imunização e preparar-se para futuras crises sanitárias.

Use of existing systematic reviews for the development of evidence-based vaccination recommendations: Guidance from the SYSVAC expert panel.

National immunization technical advisory groups (NITAGs) develop immunization-related recommendations and assist policy-makers in making evidence informed decisions. Systematic reviews (SRs) that summarize the available evidence on a specific topic are a valuable source of evidence in the development of such recommendations. However, conducting SRs requires significant human, time, and financial resources, which many NITAGs lack. Given that SRs already exist for many immunization-related topics, and to prevent duplication and overlap of reviews, a more practical approach may be for NITAGs to use existing SRs. Nevertheless, it can be challenging to identify relevant SRs, to select one SR from among multiple SRs, or to critically assess and effectively use them. To support NITAGs, the London School of Hygiene and Tropical Medicine, Robert Koch Institute and collaborators developed the SYSVAC project, which consists of an online registry of systematic reviews on immunization-related topics and an e-learning course, that supports the use of them (both freely accessible at https://www.nitag-resource.org/sysvac-systematic-reviews). Drawing from the e-learning course and recommendations from an expert panel, this paper outlines methods for using existing systematic reviews when making immunization-related recommendations. With specific examples and reference to the SYSVAC registry and other resources, it offers guidance on locating existing systematic reviews; assessing their relevance to a research question, up-to-dateness, and methodological quality and/or risk of bias; and considering the transferability and applicability of their findings to other populations or settings.

[Routine immunization 2020 in Chile during the SARS-CoV-2 pandemic]. / Vacunación programática 2020 en Chile en tiempos de pandemia por SARS-CoV-2.

In March 2020, the World Health Organization (WHO) recommended that vaccination not be interrupted as long as countries could safely maintain this service in the context of the SARS-CoV-2 pandemic. WHO also warned about the risk of interruption of programmatic vaccination that generates an increase in the number of people susceptible to infections that are sought to be prevented with the use of vaccines and, therefore, an increase in the probability of disease outbreak. Along with increased morbidity and mortality in risk groups, vaccine-preventable disease outbreaks would put additional demand on the health system already burdened by COVID-19. In August 2020, WHO reported the interruption of essential health services in different countries as a result of the SARS-CoV-2 pandemic, which mainly affected routine and extramural vaccination. In Chile, routine vaccination coverage decreased during 2020 compared to the average coverage for the 2015-2019 period. The smallest decline was 0.39% for the hexavalent vaccine at 2 months of age and the largest decrease was 12.02% at 18 months for the same vaccine. The exception to the fall in coverage in 2020 was adult pneumococcal vaccination, which showed an increase of 0.8% compared to 2015-2019.

[Seasonal influenza campaign 2020 in the context of SARS-CoV-2 pandemic: an unprecedented public health experience in Chile]. / Campaña influenza 2020 en contexto de pandemia por SARS-CoV-2: una experiencia inédita de salud pública en Chile.

In Chile, the Immunization Department of the Ministry of Health has carried out the seasonal influenza vaccination campaign annually since 1982 in collaboration with the national health services, regional health offices, and primary health care centres. With the aim of preventing deaths and serious morbidity in high-risk groups and preserving the integrity of health services, the seasonal influenza campaign had been the largest implemented in Chile until 2020, since in 2021 the vaccination campaign against SARS-CoV-2 is expected to become the largest ever implemented. In response to local demographic and epidemiological changes, and taking into account the new scientific evidence on the safety and immunogenicity of vaccines, the influenza vaccines available in Chile would increase annually as a result of campaign planning. In 2020, the influenza campaign had to be re-planned while in progress due to the addition of new high-risk groups to be vaccinated in accordance with the SARS-CoV-2 pandemic health alert modification of March 6th, 2020. Over the course of three weeks, the Immunization Department managed to increase the doses of available influenza vaccines from 6,799,800 previously agreed upon to 8,480,325 and thus serve high-risk groups, guaranteeing their access to state funded influenza vaccination.

[Consolidated recommendations of the Advisory Committee on Vaccines and Immunization Strategies- on prioritizing COVID-19 vaccination]. / Consolidado de recomendaciones del Comité Asesor de Vacunas y Estrategias de Inmunización-CAVEI, sobre priorización de vacunación COVID-19.

COVID-19 is a global public health issue due to its epidemic nature that, to date, lacks pharmacological treatment. However, some COVID-19 vaccines have been authorized for emergency use, although the duration of their protection, their ability to interrupt viral transmission, and their efficacy against emerging variants of SARS-CoV-2 are being studied. Chile's SARS-CoV-2 vaccination campaign required design and planning, like any other campaign. This process included the prioritization of risk groups for vaccination given the limited supply of COVID-19 vaccines globally. Throughout 2020, CAVEI issued recommendations on the prioritization of population groups to be vaccinated against SARS-CoV-2 in response to different needs and in accordance with available evidence. These recommendations are consolidated in Table 1 in this report. In summary, it was recommended that healthcare workers, people in long-term residences and essential State personnel be vaccinated in phase 1. In phase 2, persons over 65 years of age and people with comorbidities. In phase 3, essential tasks workers and, lastly, the general population.

Vacunación programática 2020 en Chile en tiempos de pandemia por SARS-CoV-2 / Routine immunization 2020 in Chile during the SARS-CoV-2 pandemic

Resumen En marzo de 2020, la Organización Mundial de la Salud (OMS) hizo un llamado a mantener la vacunación programática siempre que se pudieran garantizar condiciones seguras frente a la circulación de SARS-CoV-2. Asimismo, advirtió sobre el riesgo de interrupción de la vacunación programática secundaria a la pandemia por SARS-CoV-2. La interrupción de la vacunación genera un aumento en el número de personas susceptibles a las enfermedades que se busca prevenir y, así, de la probabilidad de uno o más brotes epidémicos. Estos, junto con incrementar la morbilidad y mortalidad en los grupos de riesgo, significarían una carga adicional al ya demandado sistema de salud por COVID-19. En agosto 2020, la OMS reportó interrupción de los servicios de salud esenciales en distintos países a raíz de la pandemia de SARS-CoV-2, afectando con mayor frecuencia a la vacunación de rutina y extramural. En Chile, la vacunación programática durante el 2020 disminuyó respecto del promedio del período 2015-2019, con la menor caída en la vacunación de los 2 meses de edad con hexavalente (0,39%) y la mayor a los 18 meses también con hexavalente (12,02%). La excepción fue la vacunación antineumocócica del adulto, con un incremento de 0,8% respecto del período 2015-2019.

Abstract In March 2020, the World Health Organization (WHO) recommended that vaccination not be interrupted as long as countries could safely maintain this service in the context of the SARS-CoV-2 pandemic. WHO also warned about the risk of interruption of programmatic vaccination that generates an increase in the number of people susceptible to infections that are sought to be prevented with the use of vaccines and, therefore, an increase in the probability of disease outbreak. Along with increased morbidity and mortality in risk groups, vaccine-preventable disease outbreaks would put additional demand on the health system already burdened by COVID-19. In August 2020, WHO reported the interruption of essential health services in different countries as a result of the SARS-CoV-2 pandemic, which mainly affected routine and extramural vaccination. In Chile, routine vaccination coverage decreased during 2020 compared to the average coverage for the 2015-2019 period. The smallest decline was 0.39% for the hexavalent vaccine at 2 months of age and the largest decrease was 12.02% at 18 months for the same vaccine. The exception to the fall in coverage in 2020 was adult pneumococcal vaccination, which showed an increase of 0.8% compared to 2015-2019.

Using existing systematic reviews for developing vaccination recommendations: Results of an international expert workshop.

National immunization technical advisory groups (NITAGs) develop immunization-related recommendations. Systematic reviews are recommended to be used in this process, but conducting them requires significant resources, which many NITAGs lack. Using existing systematic reviews could help address this problem. The Robert Koch Institute and collaborators set up the SYSVAC2 project to facilitate the retrieval of existing systematic reviews and offer guidance on using them. This will include an online registry of systematic reviews relevant to immunization policy and an online course on how to use existing reviews. This report describes an international expert workshop held in December 2019 to develop consensus on methods for using existing reviews and other relevant factors for the registry and course. Members from NITAGs representing different regions of the world presented their experiences of using systematic reviews and reflected on challenges inhibiting use. Three methodologists considered different aspects of using systematic reviews. Interactive sessions followed, where implications for SYSVAC2 were discussed. Participants supported having critical appraisal ratings, plain language summaries, keyword search, and data visualization functions in the registry. They suggested tailoring course content to different audiences and including overviews of reviews as a topic and examples of how NITAGs have used or could use existing reviews. Participants agreed that whether a review is out-of-date should be decided by those using the review rather than registry staff. The registry could help by highlighting the date of literature search or included primary studies. Participants recommended a visualization function to highlight overlap across reviews and guidance on handling challenges to using reviews, ideally, involving a practical element. No consensus was reached on which critical appraisal tool to use for reviews in the registry, but a majority of participants wanted registry staff to perform appraisals. Formative research is planned before the registry and online course are launched in 2020.

Campaña influenza 2020 en contexto de pandemia por SARS-CoV-2: una experiencia inédita de salud pública en Chile / Seasonal influenza campaign 2020 in the context of SARS-CoV-2 pandemic: an unprecedented public health experience in Chile

Resumen Desde 1982, cada año el Departamento de Inmunizaciones del Ministerio de Salud de Chile lleva a cabo la campaña de vacunación contra influenza junto con las Secretarías Regionales Ministeriales-SEREMI, Servicios de Salud y centros de atención primaria de salud. Con los objetivos de prevenir mortalidad y morbilidad grave en grupos de mayor riesgo y de preservar la integridad de los servicios de salud, hasta el 2020 las campañas de vacunación contra influenza serían las más grandes implementadas en Chile, para dar paso, el 2021, a la vacunación contra SARS-CoV-2. Obedeciendo a cambios demográficos y epidemiológicos locales y acogiendo los avances científicos sobre seguridad e inmunogenicidad de la vacuna, el incremento de las vacunas influenza disponibles en Chile forma parte de la planificación anual de la campaña. El 2020, sin embargo, la Campaña Influenza tuvo que ser re-planificada en curso como consecuencia de la incorporación de nuevos grupos a vacunar según dispuso la modificación de la alerta sanitaria por brote de SARS-CoV-2 del 6 de marzo de 2020. Así, de 6.799.800 de dosis, el Departamento de Inmunizaciones logró en menos de dos meses aumentar la disponibilidad a 8.480.325, y cumplir con el compromiso de garantizar el acceso de los grupos de riesgo al beneficio de la vacunación estatal gratuita.

Abstract In Chile, the Immunization Department of the Ministry of Health has carried out the seasonal influenza vaccination campaign annually since 1982 in collaboration with the national health services, regional health offices, and primary health care centres. With the aim of preventing deaths and serious morbidity in high-risk groups and preserving the integrity of health services, the seasonal influenza campaign had been the largest implemented in Chile until 2020, since in 2021 the vaccination campaign against SARS-CoV-2 is expected to become the largest ever implemented. In response to local demographic and epidemiological changes, and taking into account the new scientific evidence on the safety and immunogenicity of vaccines, the influenza vaccines available in Chile would increase annually as a result of campaign planning. In 2020, the influenza campaign had to be re-planned while in progress due to the addition of new high-risk groups to be vaccinated in accordance with the SARS-CoV-2 pandemic health alert modification of March 6th, 2020. Over the course of three weeks, the Immunization Department managed to increase the doses of available influenza vaccines from 6,799,800 previously agreed upon to 8,480,325 and thus serve high-risk groups, guaranteeing their access to state funded influenza vaccination.

Consolidado de recomendaciones del Comité Asesor de Vacunas y Estrategias de Inmunización-CAVEI, sobre priorización de vacunación COVID-19 / Consolidated recommendations of the Advisory Committee on Vaccines and Immunization Strategies- on prioritizing COVID-19 vaccination

Resumen El COVID-19 es un problema de salud pública mundial por su carácter epidémico que, a la fecha, carece de tratamiento farmacológico. Sin embargo, ya se cuenta con algunas vacunas autorizadas para uso en emergencia, aunque la duración de su protección, su capacidad para interrumpir la transmisión viral y su eficacia frente a variantes emergentes de SARS-CoV-2 se encuentran en estudio. La campaña de vacunación contra SARS-CoV-2 de Chile requirió de diseño y planificación, como toda campaña. Parte de estos fue la priorización de grupos objetivo de vacunar, necesaria debido a que el mundo se vería enfrentado a un suministro limitado de vacunas COVID-19. En distintos momentos del año 2020, el CAVEI emitió recomendaciones sobre priorización de grupos de población a vacunar contra SARS-CoV-2, respondiendo a diferentes necesidades y según la evidencia disponible en cada instancia. Éstas se consolidan en la Tabla 1 de este informe. Resumidamente, en fase 1 se recomendó vacunar al personal de salud, residencias de larga estadía y personal crítico del Estado. En fase 2, a personas mayores de 65 años y población con comorbilidades. En fase 3, a personas que cumplen labores esenciales y, finalmente, a la población general.

Abstract COVID-19 is a global public health issue due to its epidemic nature that, to date, lacks pharmacological treatment. However, some COVID-19 vaccines have been authorized for emergency use, although the duration of their protection, their ability to interrupt viral transmission, and their efficacy against emerging variants of SARS-CoV-2 are being studied. Chile's SARS-CoV-2 vaccination campaign required design and planning, like any other campaign. This process included the prioritization of risk groups for vaccination given the limited supply of COVID-19 vaccines globally. Throughout 2020, CAVEI issued recommendations on the prioritization of population groups to be vaccinated against SARS-CoV-2 in response to different needs and in accordance with available evidence. These recommendations are consolidated in Table 1 in this report. In summary, it was recommended that healthcare workers, people in long-term residences and essential State personnel be vaccinated in phase 1. In phase 2, persons over 65 years of age and people with comorbidities. In phase 3, essential tasks workers and, lastly, the general population.

Priorización de nuevas vacunas e innovación al servicio de estrategias de vacunación / New vaccines prioritization and immunization-related innovation

La vacunación es el medio más efectivo para controlar la morbilidad y mortalidad relacionadas con enfermedades infecciosas. Para lograr esto, necesitamos vacunas inmunogénicas y seguras que faciliten y mejoren sus condiciones de transporte, almacenamiento y administración. Gracias a los avances en inmunología y bioinformática, es posible impulsar el descubrimiento de nuevas vacunas para enfrentar la tuberculosis, el virus respiratorio sincicial, el Streptococcus agalactiae, la enfermedad meningocócica invasora, entre otros. Así también, nuevas tecnologías, como la producción de vacunas utilizando plantas transgénicas y parches de microagujas, los cuales podrían facilitar la producción, disminuir los costos y efectos adversos. Sin embargo, no solo necesitamos las vacunas, sino que debemos conocer la epidemiología de las enfermedades prevenibles con vacuna para tomar decisiones fundadas, con el objetivo de planificar estrategias sanitarias, medir su impacto y evaluar la seguridad de su utilización, para alcanzar las metas de salud pública y la confianza de la población.

Vaccination is the most effective strategy to avoid morbidity and mortality related to infectious diseases. To achieve this, we need immunogenic and safe vaccines that facilitate and improve its transport, storage and administration conditions. Thanks to current advances in immunology and bioinformatics, it is possible to boost the discovery of new vaccines to deal with tuberculosis, the respiratory syncytial virus, Streptococcus agalactiae, meningococcal invasive disease, among others. In addition to new technologies such as the production of plant-based vaccines, and microneedles patches, which can facilitate its production, reducing costs and adverse effects. However, vaccines is not the only thing that we need, because we must know the epidemiology and burden of disease to take informed decisions to design optimal strategies, measuring their impact and assessing the safety of their use in order to achieve the goals health and population confidence.

Predicting nationwide obesity from food sales using machine learning.

The obesity epidemic progresses everywhere across the globe, and implementing frequent nationwide surveys to measure the percentage of obese population is costly. Conversely, country-level food sales information can be accessed inexpensively through different suppliers on a regular basis. This study applies a methodology to predict obesity prevalence at the country-level based on national sales of a small subset of food and beverage categories. Three machine learning algorithms for nonlinear regression were implemented using purchase and obesity prevalence data from 79 countries: support vector machines, random forests and extreme gradient boosting. The proposed method was validated in terms of both the absolute prediction error and the proportion of countries for which the obesity prevalence was predicted satisfactorily. We found that the most-relevant food category to predict obesity is baked goods and flours, followed by cheese and carbonated drinks.

Structural Equation Modelling in the exploration and analysis of intrauterine environmental exposures with infant health effects.

INTRODUCTION: In epidemiology, generalized linear models are the main statistical methods used to explore associations. However, the use of other methods such as Structural Equation Modelling (SEM) is gradually increasing. OBJECTIVE: The aim of the study was to illustrate the use of SEM in the assessment of salivary cortisol concentration in infants as a biomarker of perinatal exposure to inorganic arsenic. MATERIAL AND METHODS: This was a cohort study of pregnant women recruited from public health care centres in Arica, Chile, in 2013. Socio-demographic information and urine samples to assess inorganic arsenic were collected during the second trimester of pregnancy. Saliva samples were collected to assess cortisol in infants between 18-24 months of age. Four linear regression models (LRMs) and two SEMs were run to estimate the effect of prenatal exposure to inorganic arsenic on cortisol concentration in infants. RESULTS: According to LRMs and SEMs, prenatal exposure to inorganic arsenic and salivary cortisol were not associated. However, the association between maternal cortisol and cortisol in infants was statistically significant in all models; for each increase in standard deviation of the covariate Ln(maternal cortisol), the outcome Ln(cortisol in infant) increased by 0.49 units of variance in both SEMs. CONCLUSIONS: LRMs and SEMs were useful to assess the effect of prenatal exposure to inorganic arsenic on cortisol in infants. However, SEM allowed the adjustment of estimations by an estimated latent that obtained the information about income, occupation, education and ethnicity in a more comprehensive way than achieved by LRM.

Chile's National Advisory Committee on Immunization (CAVEI): Evidence-based recommendations for public policy decision-making on vaccines and immunization.

A National Immunization Technical Advisory Group (NITAG) provides independent, evidence-based recommendations to the Ministry of Health for immunization programmes and policy formulation. In this article, we describe the structure, functioning and work processes of Chile's NITAG (CAVEI) and assess its functionality, quality of work processes and outputs, and integration of the committee into the Ministry of Health policy process using the Assessment tool for National Immunization Technical Advisory Groups. Among its strengths, CAVEI's administrative and work plasticity allows it to respond in a timely manner to the Ministry of Health's requests and proactively raise subjects for review. Representation of multiple areas of expertise within the committee makes CAVEI a robust and balanced entity for the development of evidence-based comprehensive recommendations. High ranking profile of the Secretariat structure furthers CAVEI's competences in policymaking and serves as a bridge between the committee and international initiatives in the field of immunizations.