On May 15, 2014, CDC was notified of two laboratory-confirmed measles cases in the Federated States of Micronesia (FSM), after 20 years with no reported measles. FSM was assisted by the World Health Organization (WHO), the United Nations Children’s Fund (UNICEF), and CDC in investigating suspected cases, identify contacts, conduct analyses to guide outbreak vaccination response, and review vaccine cold chain practices. During February–August, three of FSM’s four states reported measles cases: Kosrae (139 cases), Pohnpei (251), and Chuuk (3). Two thirds of cases occurred among adults aged ≥20 years; of these, 49% had received ≥2 doses of measles-containing vaccine (MCV). Apart from infants aged <12 months who were too young for routine vaccination, measles incidence was lower among children than adults. A review of current cold chain practices in Kosrae revealed minor weaknesses; however, an absence of historical cold chain maintenance records precluded an evaluation of earlier problems. Each state implemented vaccination campaigns targeting children as young as age 6 months through adults up to age 57 years. The preponderance of cases in this outbreak associated with vaccine failure in adults highlights the need for both thorough case investigation and epidemiologic analysis to guide outbreak response vaccination. Routine childhood vaccination coverage achieved in recent years limited the transmission of measles among children. Even in areas where transmission has not occurred for years, maintaining high 2-dose MCV coverage through routine and supplemental immunization is needed to prevent outbreaks resulting from increased measles susceptibility in the population.

Efforts to control and eliminate measles and rubella are aided by high-quality surveillance data—supported by laboratory confirmation—to guide decision-making on routine immunization strategies and locations for conducting preventive supplementary immunization activities (SIAs) and outbreak response. Important developments in rapid diagnostic tests (RDTs) for measles and rubella present new opportunities for the global measles and rubella surveillance program to greatly improve the ability to rapidly detect and respond to outbreaks. Here, we review the status of RDTs for measles and rubella Immunoglobulin M (IgM) testing, as well as ongoing questions and challenges regarding the operational use and deployment of RDTs as part of global measles and rubella surveillance. Efforts to develop IgM RDTs that can be produced at scale are underway. Once validated RDTs are available, clear information on the benefits, challenges, and costs of their implementation will be critical for shaping deployment guidance and informing country plans for sustainably deploying such tests. The wide availability of RDTs could provide new programmatic options for measles and rubella elimination efforts, potentially enabling improvements and flexibility for testing, surveillance, and vaccination.

A better understanding of population-level factors related to measles case fatality is needed to estimate measles mortality burden and impact of interventions such as vaccination. This study aimed to develop a conceptual framework of mechanisms associated with measles case fatality ratios (CFRs) and assess the scope of evidence available for related indicators. Using expert consultation, we developed a conceptual framework of mechanisms associated with measles CFR and identified population-level indicators potentially associated with each mechanism. We conducted a literature review by searching PubMed on 31 October 2021 to determine the scope of evidence for the expert-identified indicators. Studies were included if they contained evidence of an association between an indicator and CFR and were excluded if they were from non-human studies or reported non-original data. Included studies were assessed for study quality. Expert consultation identified five mechanisms in a conceptual framework of factors related to measles CFR. We identified 3772 studies for review and found 49 studies showing at least one significant association with CFR for 15 indicators (average household size, educational attainment, first- and second-dose coverage of measles-containing vaccine, human immunodeficiency virus prevalence, level of health care available, stunting prevalence, surrounding conflict, travel time to major city or settlement, travel time to nearest health care facility, under-five mortality rate, underweight prevalence, vitamin A deficiency prevalence, vitamin A treatment, and general malnutrition) and only non-significant associations for five indicators (antibiotic use for measles-related pneumonia, malaria prevalence, percent living in urban settings, pneumococcal conjugate vaccination coverage, vitamin A supplementation). Our study used expert consultation and a literature review to provide additional insights and a summary of the available evidence of these underlying mechanisms and indicators that could inform future measles CFR estimations.

Global measles vaccine coverage has stagnated at approximately 85% for over a decade. By simplifying vaccine logistics and administration, the measles and rubella microarray patch (MR-MAP) may improve coverage. Clinical trials have demonstrated similar safety and immunogenicity in 9-month-old infants for MR-MAPs compared with syringe-and-needle vaccination. To aid commercialization, we present estimates of MR-MAP demand. We created a spreadsheet-based tool to estimate demand for MR-MAPs using data from 180 WHO countries during 2000–2016. Five immunization scenarios were analyzed: (1a) Supplementary Immunization Activities (SIAs) in Gavi, the Vaccine Alliance (Gavi)-eligible countries and (1b) WHO countries where preventive SIAs are routinely conducted; (2) SIAs and outbreak response immunization in all WHO countries; (3) routine immunization (RI) and SIAs in six high-burden measles countries (the Democratic Republic of the Congo, Ethiopia, India, Indonesia, Nigeria, and Pakistan); (4) RI and SIAs in six high-burden countries and Gavi-eligible countries; and (5) hard-to-reach populations. MR-MAP demand varied greatly across scenarios. Forecasts for 2025–2034 estimate from 137 million doses in hard-to-reach populations (scenario 5) to 2.587 billion doses for RI and SIAs in six high-burden countries and Gavi-eligible countries (scenario 4). When policymakers and manufacturers assess MR-MAP demand, they may consider multiple scenarios to allow for a complete consideration of potential markets and public health needs.