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. Interviewers from an independent polling company administered a survey to 4802 parents and guardians of children aged <5 years in these regions. To better assess barriers to vaccination, the study was designed to have 70% of participants who had children with incomplete vaccination schedules. Explanatory factorial, principal component, and cluster analyses were performed to place participants into a group (segment) representing the primary category of reasons respondents offered for not vaccinating their children. Types of barriers were then compared to other variables, such as service quality, communication preferences, and parental attitudes on vaccination. Results: Although all respondents indicated that vaccines have health benefits, and 4738 (98.7%) possessed vaccination cards for their children, attitudes and knowledge were not always favorable to immunization. Six groups of immunization barriers were identified: 1) factors related to caregivers (24.4%), 2) vaccinators (19.7%), 3) health centers (18.0%), 4) the health system (13.4%), 5) concerns about adverse events (13.1%), and 6) cultural and religious beliefs (11.4%); groups 1, 5 and 6 together represented almost half (48.9%) of users, indicating problems related to the demand for vaccines as the primary barriers to immunization. Differences in demographics, communication preferences, and reported service quality were found among participants in the six groups and among participants in the 10 regions. Additionally, differences between how participants reported receiving information on vaccination and how they believed such information should be communicated were observed. Conclusions: Better understanding immunization barriers and the users of the EPI can help tailor communication strategies to increase demand for immunization services. Results of the study have been used by Colombia’s EPI to inform the design of new communication strategies.

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. Methods: Based on administrative coverage levels and socio-demographic indicators in Guatemala’s 22 geographical departments, five were designated as low-coverage and five as high-coverage areas. Overall, 1194 parents and guardians of children aged 0–5 years were interviewed in these 10 departments. We compared indicators between low- and high-coverage areas and identified risk factors associated with undervaccination. Results: Of the 1593 children studied, 29 (1.8%) were determined to be unvaccinated, 458 (28.8%) undervaccinated, and 1106 (69.4%) fully vaccinated. In low-coverage areas, children of less educated (no education: RR = 1.49, p = 0.01; primary or less: 1.39, p = 0.009), older (aged >39 years: RR =1.31, p = 0.05), and single (RR = 1.32, p = 0.03) parents were more likely to have incomplete vaccination schedules. Similarly, factors associated with undervaccination in high-coverage areas included the caregiver’s lack of education (none: RR = 1.72, p = 0.0007; primary or less: RR = 1.30, p = 0.05) and single marital status (RR = 1.36, p = 0.03), as well as the child’s birth order (second: RR = 1.68, p = 0.003). Although users generally approved of immunization services, problems in service quality were identified. According to participants, topics such as the risk of adverse events (47.4%) and next vaccination appointments (32.3%) were inconsistently communicated to parents. Additionally, 179 (15.0%) participants reported the inability to vaccinate their child on at least one occasion. Compared to high-coverage areas, participants in low-coverage areas reported poorer service, longer wait times, and greater distances to health centers. In high-coverage areas, participants reported less knowledge about the availability of services. Conclusions: Generally, immunization barriers in Guatemala are related to problems in accessing and attaining high-quality immunization services rather than to a population that does not adequately value vaccination. We provide recommendations to aid the country in maintaining its achievements and addressing new challenges.

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.

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. From 2020 to 2022, regional coverage with first (MMR-1) and second doses (MMR-2) decreased to rates below 90%. The regional suspected case notification rate was maintained above the minimum expected 2.0 suspect cases per 100,000 population, except in 2021. During 2019 to 2023, 18 countries experienced outbreaks, with two of the outbreaks resulting in re-established endemic transmission. In conclusion, two countries in the Americas have not maintained measles elimination, but by the end of 2023 no country showed endemic measles transmission. One of the countries that lost its certification of elimination in 2018 managed to be reverified in 2023; the other is pending reverification. All countries maintained rubella elimination. Despite these challenges, the sustainability of the elimination of these diseases remains a health priority in the Region.

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. 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. Health records were reviewed to assess vaccination coverage and timeliness. Parents and/or guardians and principals of all 86 schools were interviewed regarding knowledge, attitudes, and practices related to vaccination. Of 767 children included, 75% were vaccinated with MMR2 (n = 572); 46.7% were vaccinated in a timely manner, i.e., by 5 years of age. Cohorts born in 2004, 2005, and 2008 reported the lowest proportion. 'Mothers as caregivers' was positively associated with timely MMR2 vaccination. Although 97% of principals surveyed considered vaccination important, 48.8% were not aware of national legislation requiring complete vaccination prior to school entry. Survey results concurred with the low MMR2 administrative coverage rates reported by Saint Lucia, much lower than the recommended 95%. Based on the results of this survey, Saint Lucia's national immunization program has lowered the age of MMR2 to 18 months in 2016, increased advocacy with schools to enforce the school-entry law, and is working to vaccinate the cohorts of children who have not received timely MMR2.

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. This review examines multiple PAHO and WHO data points, documents and reports related to measles/rubella vaccination coverage and VWA since its inception. Its goal is to document the impact that the VWA has had in maintaining and accelerating measles and rubella disease elimination, in the context of PAHO’s Disease Elimination Initiative. The results suggest that VWA’s contributions to measles and rubella elimination have been substantial. Every year, VWA promotes (a) renewed political commitment to the immunization program from the highest political authorities of Member States; (b) vaccination operations to close immunity gaps, recover under-vaccinated persons, and reach chronically underserved populations; and (c) the dissemination of messages on the benefits of vaccination through regional and national communications campaigns. VWA will continue to be an important contributor to disease elimination efforts in the Americas, even as new targets are set in response to the evolving epidemiological landscape.