[Successes and challenges in achieving and sustaining the elimination of measles, rubella, and congenital rubella syndrome in the Americas, 2013-2023Conquistas e desafios para alcançar e manter a eliminação do sarampo, da rubéola e da síndrome da rubéola congênita na Região das Américas, 2013-2023].

Objetivo: To document the historical facts and the challenges faced in the Region of the Americas in achieving and sustaining measles, rubella, and congenital rubella syndrome (CRS) elimination between 2013 and 2023.

Method: Special report with a narrative description of the main achievements, challenges, and lessons learned during the period, and an analysis of vaccination coverage, surveillance indicators, and measles outbreaks using data from the Pan American Health Organization and the United Nations Children's Fund, among others.

Results: Between 2003 and 2016, regional vaccination coverage with the first dose of the measles, rubella, and mumps vaccine was between 92% and 94%; after 2017 there was a marked decline due to lower coverage levels in the most populous countries.

[Risk factors and control measures in measles outbreaks in countries of the Region of the Americas, 2017-2023Fatores de risco e medidas de controle em surtos de sarampo em países da Região das Américas, 2017-2023].

Objective: To document and compare risk factors and control measures for the largest measles outbreaks in the post-elimination era in the Region of the Americas.

Methods: Description of risk factors such as vaccination coverage, notification rate of suspected cases, measles incidence, and a summary of control measures for major measles outbreaks in six countries from 2017 to 2023. The analysis also includes a review of outbreak characteristics (time, place, and person).

Vaccination Week in the Americas: An Ongoing Initiative to Strengthen and Sustain Measles and Rubella Elimination in the Region.

Vaccination Week in the Americas (VWA) is a yearly regional initiative that promotes the benefits of vaccination to all persons in the region. In its 22-year history, more than 1.15 billion people have been reached under the framework of VWA across more than 40 countries and territories.

Sustaining the Elimination of Measles, Rubella and Congenital Rubella Syndrome in the Americas, 2019-2023: From Challenges to Opportunities.

This report reviews national data from all Member States on measles, rubella, and congenital rubella syndrome (CRS) elimination in the Region of the Americas during 2019-2023. It includes an analysis of compliance with vaccination coverage, surveillance indicators, and measles outbreaks, as well as an analysis of the response capacity of the laboratory network and a country case study that meets all indicators. The sources of information were the integrated epidemiological surveillance system for measles and rubella of the Pan American Health Organization (PAHO)/World Health Organization (WHO) and the Joint Reporting Form (eJRF), among others.

MMR2 vaccination coverage and timeliness among children born in 2004 - 2009: a national survey in Saint Lucia, 2015.

Objectives: To more accurately determine coverage and timeliness of the second dose of measles-mumps-rubella vaccine (MMR2), while identifying factors associated with low MMR2 vaccination uptake among children in Saint Lucia.

Methods: A survey was conducted in October - November 2015 targeting children born in 2004 - 2009. At 86 preschools and primary schools, two children from each grade were randomly selected, yielding an effective sample of 836 children.

Public health responses during measles outbreaks in elimination settings: Strategies and challenges.

In late September 2016, the Americas became the first region in the world to have eliminated endemic transmission of measles virus. Several other countries have also verified measles elimination, and countries in all six World Health Organization regions have adopted measles elimination goals. The public health strategies used to respond to measles outbreaks in elimination settings are thus becoming relevant to more countries.

Risk analysis for the reintroduction and transmission of measles in the post-elimination period in the Americas.

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[Risk matrix for estimating imported outbreaks of measles or rubella in ChileMatriz de risco para estimar surtos importados de sarampo ou rubéola aplicada ao Chile].

Objective: Develop a risk matrix to evaluate the ongoing risk of measles and rubella outbreaks associated with imported cases in Chile.

Methods: The risk assessment tools were developed in the following stages: preparation and approval of biological, programmatic, and demographic variables; weighting of the selected variables by a panel of experts; calculation of the risk index; specialization; and knowledge transfer.

Results: Of the 346 Chilean communes analyzed, 34% were in the high-risk interval for experiencing a measles and rubella outbreak with the introduction of the virus, 59%, in the average-risk interval, and 3%, in the low-risk interval.

Building capacity for active surveillance of vaccine adverse events in the Americas: A hospital-based multi-country network.

New vaccines designed to prevent diseases endemic in low and middle-income countries are being introduced without prior utilization in countries with robust vaccine pharmacovigilance systems. Our aim was to build capacity for active surveillance of vaccine adverse events in the Americas. We describe the implementation of a proof-of-concept study for the feasibility of an international collaborative hospital-based active surveillance system for vaccine safety.

Operational lessons learned in conducting a multi-country collaboration for vaccine safety signal verification and hypothesis testing: The global vaccine safety multi country collaboration initiative.

Timely and effective evaluation of vaccine safety signals for newly developed vaccines introduced in low and middle- income countries (LMICs) is essential. The study tested the development of a global network of hospital-based sentinel sites for vaccine safety signal verification and hypothesis testing. Twenty-six sentinel sites in sixteen countries across all WHO regions participated, and 65% of the sites were from LMIC.

Enhancing global vaccine pharmacovigilance: Proof-of-concept study on aseptic meningitis and immune thrombocytopenic purpura following measles-mumps containing vaccination.

New vaccines designed to prevent diseases endemic in low and middle-income countries (LMICs) are now being introduced without prior record of utilization in countries with robust pharmacovigilance systems. To address this deficit, our objective was to demonstrate feasibility of an international hospital-based network for the assessment of potential epidemiological associations between serious and rare adverse events and vaccines in any setting. This was done through a proof-of-concept evaluation of the risk of immune thrombocytopenic purpura (ITP) and aseptic meningitis (AM) following administration of the first dose of measles-mumps-containing vaccines using the self-controlled risk interval method in the primary analysis.

Missed Opportunities for Vaccination in the Dominican Republic: Results of an Operational Investigation.

. Despite the success of the Dominican Republic's National Immunization Program, homogenous vaccine coverage has not been achieved. In October 2012, the country implemented a study on missed opportunities for vaccination (MOVs) in children aged <5 years.

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

All six World Health Organization (WHO) regions have now set goals for measles elimination by or before 2020. To prioritize measles elimination efforts and use available resources efficiently, there is a need to identify at-risk areas that are offtrack from meeting performance targets and require strengthening of programmatic efforts. This article describes the development of a WHO measles programmatic risk assessment tool to be used for monitoring, guiding, and sustaining measles elimination efforts at the subnational level.

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.

Understanding the main barriers to immunization in Colombia to better tailor communication strategies.

Background: The Expanded Program on Immunization (EPI) in Colombia has made great advances since its inception in 1979; however, by 2010 vaccination coverage rates had been declining. In 2010, the EPI commissioned a nationwide study on practices on immunization, attitudes and knowledge, perceived service quality, and barriers to childhood immunization in order to tailor EPI communication strategies.

Methods: Colombia's 32 geographical departments were divided into 10 regions.

From the parents' perspective: a user-satisfaction survey of immunization services in Guatemala.

Background: Immunization coverage levels in Guatemala have increased over the last two decades, but national targets of ≥95% have yet to be reached. To determine factors related to undervaccination, Guatemala's National Immunization Program conducted a user-satisfaction survey of parents and guardians of children aged 0-5 years. Variables evaluated included parental immunization attitudes, preferences, and practices; the impact of immunization campaigns and marketing strategies; and factors inhibiting immunization.

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.