Background: Vaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90–95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns.Methods: We combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination.Results: We found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5–9-year-olds than established previously.Conclusions: The immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5–9-year-olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.

Introduction: The aging homeless population currently makes up half the general homeless population. However, there are few homeless emergency shelters that can address their needs. This results in an overutilization of inpatient admissions and emergency room services. Methods: Homeless service staff from VA Palo Alto Health Care System partnered with a local homeless emergency housing provider, Compassion Residio Services Inc., to implement this new model of care for aging, medically fragile homeless Veterans. This emergency housing model utilizes practices done in geriatric settings. This model aimed to help decrease the utilization of emergency departments and inpatient admissions. Results: The average cost of emergency department visits and inpatient admissions was $127,314 per Veteran 6 months before admission. Six months after discharge, the average cost of treatment from emergency department visits and inpatient admissions was roughly $59,546 after discharge, a 53% decrease. Emergency department visits decreased from an average of 5.6 visits per Veteran 6 months before admission to 2.65 visits after 6 months discharge. The number of inpatient nights decreased from an average of 15 days per admission in the 6 months before the program to 13 days. Total admissions decreased by nearly half from 48 the previous 6 months to 25 after 6 months. Discussion: Overall, as residents settled into stable environments tailored around geriatric care, the utilization of emergency department visits and inpatient services decreased. Furthermore, the complexity (eg, cost per encounter) also decreased.

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.

A better understanding of SARS-CoV-2 transmission from children and adolescents is crucial for informing public health mitigation strategies. We conducted a retrospective cohort study among household contacts of primary cases defined as children and adolescents aged 7⍰19 years with laboratory evidence of SARS-CoV-2 infection acquired during an overnight camp outbreak. Among household contacts, we defined secondary cases using the Council of State and Territorial Epidemiologists definition. Among 526 household contacts of 224 primary cases, 48 secondary cases were identified, corresponding to a secondary attack rate of 9% (95% confidence interval [CI], 7%–12%). Our findings show that children and adolescents can transmit SARS-CoV-2 to adult contacts and other children in a household setting.

By 2017, rubella had been officially eliminated in Australia. This success was attributed to Australia’s longstanding national immunization programme and two enhanced measles immunization activities using measles, mumps, and rubella (MMR) vaccines — the Measles Control Campaign (MCC) and the Young Adult MMR Campaign (YAC). Our study describes the impact of these activities on rubella incidence, and its elimination in Australia. Aggregate national serological survey data were assigned to birth cohorts, and mean, median, and age-group estimates calculated and analyzed against MMR immunization coverage estimates (1998–2018) and rubella notifications (1993–2018). Three-year cumulative incidences were calculated by birth cohort. The serological surveys revealed high and stable levels of rubella immunity among females, but estimates for three male cohorts were lower. Since 2007, MMR immunization coverage among children aged 24–27 months has remained above 90% for both doses. The 3-year cumulative incidence of rubella declined across all birth cohorts following the MCC and the YAC. Using MMR vaccines to address measles immunity gaps had the additional benefit of controlling rubella in Australia. Both the MCC and YAC shifted rubella epidemiology, accelerating the interruption of endemic transmission. Countries should consider combined measles and rubella vaccines for all catch-up activities.