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The Lancet Regional Health - Americas

○ Elsevier BV

Preprints posted in the last 7 days, ranked by how well they match The Lancet Regional Health - Americas's content profile, based on 22 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Patterns of Influenza Vaccine Uptake by Age Group and Product Type in Michigan, 2017-2021

Zhou, Z.; Malosh, R.; Sudan, S.; Wagner, A.; Eisenberg, M. C.; Monto, A.; Martin, E. T.

2026-10-21 epidemiology 10.64898/2026.10.19.26365920 medRxiv
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Background Influenza vaccines have seen many changes over recent years in terms of both policy recommendations and product types. Immune responses and vaccine effectiveness vary by vaccine strain composition and product type. This study aimed to explore this variation on a regional level through examining spatial and temporal autocorrelations of vaccine uptake of different product types within Michigan from 2017 to 2021. Methods Influenza vaccine administration data from the 2017/18 to 2021/22 seasons were obtained from the Michigan Care Improvement Registry. Population size estimates for 2017 and 2019 were obtained from the Michigan Department of Health and Human Services. Age-standardized and age-stratified vaccination rates were computed. Disparate county-level vaccine uptake clusters were constructed using spatial autocorrelation indicators and spatiotemporal clusters were identified using scan statistics. Linear mixed effect models were used to study the impact of social vulnerability and urbanicity level on seasonal influenza vaccination rate. Results Vaccination incidence rates for adjuvanted, recombinant, and nasal sprays vaccines and for any vaccines increased significantly through the study period. County-level spatiotemporal clusters of type-specific uptake rates were identified. Most notably, we identified an emerging cluster with high uptake of adjuvanted vaccine radiating from Ottawa County, located in suburban Grand Rapids, and the disappearance of high uptake cluster for high-dose vaccine uptake in the area. Vaccination rates by any product type were found to vary seasonally and showed weak negative association with more rural regions. The overall vaccination rates appear to be lower among counties with higher social vulnerability in certain urbanicity levels, but social vulnerability and urbanicity were not significantly associated with overall vaccination rate during the study period. Conclusions Vaccine type-specific uptake was spatially and temporally diverse in Michigan between 2017 and 2022. Mid and Northern Michigan had consistently relatively lower vaccination rate compared to other regions in Michigan.

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Epidemiologic shifts predict spatial patterns of measles re-emergence in the United States

Kumar, C. K.; Stoffel, L. A.; Warren, J. L.; Blumberg, S.; Schechter, R.; Bubar, K. M.; Fattah, M.; Kiang, M. V.; Maldonado, Y.; Mordecai, E. A.; Hotez, P. J.; Lipsitch, M.; Lo, N. C.

2026-10-16 epidemiology 10.64898/2026.10.14.26365590 medRxiv
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Globally, measles is re-emerging in countries that have previously achieved elimination, including the United States. As immunization rates decline, characterizing the dynamics and evolving spatial pattern of measles re-emergence is critical to inform the public health response. We analyze annual county-level measles cases and vaccine coverage data in the United States (US) from 2011-2025 and find a shift in measles epidemiology in recent years indicative of re-emergence. While outbreak risk is spatially concentrated, we find that outbreaks are increasingly spreading throughout the broader population and across counties, but targeted interventions are predicted to prevent re-emergence nationwide. During the first decade of this period (2011-2020), outbreaks were only weakly associated with county-level vaccine coverage and predominantly isolated to single counties; however, recently (2021-2025), vaccine coverage has become strongly associated with outbreak size and spread across neighboring counties has increased. These findings suggest that measles transmission is increasingly sustained across the broader population rather than only in socially clustered communities. We developed a spatial statistical model to predict outbreak risk and size in all US counties with validation over 2021-2025; the model predicted counties with [≥]10 cases with a sensitivity of 95% (range across 2021-2025: 75-100%) and specificity of 83% (64-98%). Mechanistic models based on county vaccine coverage alone had worse performance, particularly in predicting larger outbreaks. Using the spatial statistical model, we find that prioritizing interventions in the areas of greatest model-predicted risk (e.g., top decile of US counties) was more impactful than state-level interventions (e.g., top five states) or targeting based on low vaccine coverage alone. Achieving even modest (5 percentage point) increases in vaccine coverage in counties in the top decile of model-predicted risk reduced long-term measles risk nationwide by over 90%. Together, these findings demonstrate that predictive risk modeling to inform spatially targeted interventions can likely mitigate the re-emergence of vaccine-preventable diseases.

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Social Needs Z Codes and Subsequent Acute Care Across 21 U.S. Health Systems

Lobelo, F.; Durieux, J.; Ashoo, S.; Colovos, C.

2026-10-16 health policy 10.64898/2026.10.14.26365559 medRxiv
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Health systems increasingly record ICD-10 Z59 social-needs codes for housing, food, transportation, and related hardship to trigger referrals, report quality, and adjust risk. However code documentation occurs at varying rates and no study has separated what the code says about a patient's hardship from what it says about being documented at all. Using a linked electronic health record and claims corpus covering 4.95 million patients in 21 identifiable health systems, we matched 26,153 adults with a first outpatient Z59 code to similar uncoded patients and, as a negative control, repeated the entire design around an administrative code. Coding ranged from 1 percent to 24 percent of patients across systems and remained highly variable after adjustment for patient mix. A hardship code was associated with 67% (95% CI=1.61, 1.74) more emergency department (ED) visits and 43% ( 95% CI=1.38, 1.49) more hospital admissions in the next year (62 versus 49 of every 100 patients with any acute event). The administrative-code reproduced 46 percent of the Z59 association for ED visits and 70 percent for admissions. In the five systems with the most complete stay dates, no hardship-specific admission excess was detectable. Homelessness codes forecast two and a half times the ED visit rate. At national planning prices, excess emergency and preventable hospital care totaled roughly $2,000 to $2,500 per coded patient-year ($2,516 base scenario; about $1,100 under an exploratory assumed-discount scenario (not an estimate of hardship-attributable spending)), with the largest emergency burden among Medicaid patients. The Z code added no increment to clinical and utilization-based risk prediction models in any system.

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Claims-based reconstruction of the pancreatic cancer care pathway links centralization of care to survival

Laubr, D.; Tichopad, A.; Rybar, M.; Bielcikova, Z.; Lovecek, M.; Rozanek, M.; Donin, G.

2026-10-20 oncology 10.64898/2026.10.17.26365423 medRxiv
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Background: The organization of pancreatic cancer care may be associated with survival. Using health administrative claims data, we reconstructed the pathway from diagnosis to first-line therapy and examined associations of multidisciplinary team review and treatment at specialized centers with overall survival. Methods: Longitudinal historical cohort study using anonymized health administrative claims data from six Czech health insurance funds, covering approximately 17% of patients diagnosed with pancreatic cancer nationally between 2018 and 2020. Adults with an incident ICD-10 C25 record confirmed by imaging and histopathology were followed from the index date (the date of the first qualifying imaging or histopathological examination) until death, censoring, or 31 December 2021. Overall survival was analyzed using Kaplan-Meier methods and Cox regression adjusted for age and first-line therapy type. Results: Of 1,255 patients, 920 (73.3%) received first-line therapy and 266 (21.2%) died untreated. Among treated patients, 436 (47.4%) underwent multidisciplinary team review, 335 (36.4%) underwent surgery, and 667 (72.5%) were treated at a complex oncological center. Surgery was associated with longer overall survival than chemotherapy (age-adjusted hazard ratio [HR] 0.32, P < 0.001). Treatment at a complex oncological center was associated with longer overall survival (adjusted HR 0.77, 95% confidence interval [CI] 0.64-0.92, P = 0.004; crude median 532 versus 394 days). Multidisciplinary team review was not significantly associated with overall survival (adjusted HR 0.86, 95% CI 0.73-1.01, P = 0.073). Conclusions: Treatment at a complex oncological center was associated with longer survival, while fewer than half of patients had a recorded multidisciplinary team review. How care is organized, not only which therapy is delivered, is associated with outcome. The observational design and absence of key clinical covariates limit causal interpretation.

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National incidence of coccidioidomycosis in the United States estimated through machine learning integration of epidemiological, veterinary, and socioecological data

Couper, L. I.; Camponuri, S. K.; Sykes, J. E.; Li, X.; Hubbard, A. E.; Bustamante, B. L. M.; Williamson, T.; Ruberto, I.; Sondermeyer-Cooksey, G.; Karmarkar, E. N.; Yu, A. T.; Heaney, A. K.; Head, J. R.; Remais, J. V.

2026-10-16 epidemiology 10.64898/2026.10.14.26365564 medRxiv
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Importance: Coccidioidomycosis, also known as Valley fever, is a serious fungal disease caused by inhaling Coccidioides spores aerosolized from the soil. Despite rising public health concern, the distribution and incidence of coccidioidomycosis in the US remain poorly characterized as not all states are required to report cases, and case under-ascertainment is presumed to be high, particularly outside of the endemic region. Objective: To estimate monthly, county-level coccidioidomycosis incidence across the US while accounting for widespread under-ascertainment. Design, Setting, and Participants: We integrated multisource data, including human cases diagnosed in electronic health records, serological testing of dogs, and ecological and sociodemographic predictors, in a machine learning model estimating monthly, county-level coccidioidomycosis incidence. The model was trained on surveillance data from Arizona and California from 2013 to 2023, then applied to predict incidence in states across the contiguous US over the same time period. Main Outcomes and Measures: Incidence of coccidioidomycosis at the monthly county level. Results: The model predicted coccidioidomycosis incidence from 2013 to 2023 for 3,108 counties from all states in the contiguous US. The model identified 60 counties in non-reporting states where predicted incidence was [&ge;]2 cases per 100,000 population (considered moderate to high incidence). In states with mandatory reporting outside of Arizona and California, the model predicted county-level incidence rates that were 28% higher (95% bootstrap interval, 0.1%-69.8%) than those captured in national surveillance, equating to a total of 608 potentially missed cases per year (95% bootstrap interval, 340-964). Conclusions and Relevance: In this cross-sectional study, the model quantified case under-ascertainment for coccidioidomycosis relative to Arizona and California, and highlighted the potential for alternative data sources to fill in gaps in mandatory reporting. Estimating incidence while accounting for under-ascertainment and non-reporting may help efforts to improve public and physician awareness and to detect emergence in new regions.

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Reporting of Pericardial Adverse Events with Immune Checkpoint Inhibitors: A Disproportionality Analysis of the FDA Adverse Event Reporting System

Balakrishna, K.; Bhatt, V.; Hammond, A.; Bawoke, M. M.; Fradley, M. G.; Zlotoff, D. A.; Neilan, T. G.

2026-10-21 cardiovascular medicine 10.64898/2026.10.19.26365946 medRxiv
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Background. Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events in almost any organ. While myocarditis has received the most attention, data on pericardial disease with ICI use are limited. We examined pericardial adverse event reporting with nine ICIs using the FDA Adverse Event Reporting System (FAERS). Methods. We combined legacy AERS and current FAERS quarterly files from January 2011 to June 2026 into 18,629,240 unique cases, deduplicated by case number, and removed cases the FDA had listed as deleted. ICI exposure was identified from generic names, brand names, development code names and the active-ingredient field. Pericardial events were defined by seven MedDRA preferred terms. We estimated reporting odds ratios (ROR), proportional reporting ratios (PRR), Bayesian information components (IC) and empirical Bayes geometric means (EBGM). We also examined myocarditis co-reporting, time trends, a comparison with other antineoplastic agents, a MedDRA query-based outcome, and 14 alternative definitions. Results. The analysis included 18,514,045 cases: 277,434 involved an ICI, 34,792 carried a pericardial term, and 1,680 had both. Pericardial events were reported disproportionately with ICIs (ROR 3.35 (95% CI 3.19 to 3.52); PRR 3.34; IC025 1.62). Eight of nine agents had a ROR above 1 (3.32 to 5.63). Among the most frequently reported terms, estimates were highest for cardiac tamponade (5.59 (95% CI 4.98 to 6.28)), followed by pericardial effusion (3.83 (95% CI 3.60 to 4.07)) and pericarditis (2.09 (95% CI 1.89 to 2.31)). After removing cases that also reported myocarditis, the ROR was 3.13 (95% CI 2.98 to 3.30). Most sensitivity analyses gave similar estimates (ROR 3.13 to 3.47); defining exposure by generic drug names alone, which identified only 44% of exposed cases, gave 3.99. Compared with cases naming other L01 antineoplastic agents, the ROR was 1.13 (95% CI 1.08 to 1.19): 1.28 (95% CI 1.20 to 1.36) for ICI-only cases and 0.96 (95% CI 0.89 to 1.04) when another antineoplastic was also named. The ICI-specific reporting odds ratio fell each quarter (odds ratio 0.977 per quarter, 95% CI 0.973 to 0.980). Conclusions. In FAERS, pericardial events were reported more often with ICIs than with other drugs across most agents and terms; however, incidence and causation cannot be determined. The excess over other antineoplastic agents was small, and reporting disproportionality declined over time. These findings support clinical awareness of pericardial disease in patients receiving ICIs and warrant study in data that can measure incidence.

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Vaccination and Non-School NPIs Shaped Ontario's Pre-Omicron COVID-19 Hospital Burden

Tuffaha, M. Z.; Dick, D. W.; Li, J.; Heffernan, J. M.

2026-10-16 epidemiology 10.64898/2026.10.14.26365553 medRxiv
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We develop an age- and immunity-structured COVID-19 model with setting-specific contacts, calibrated to Ontario incidence and hospital admissions before Omicron. We simulate counterfactual vaccination strategies and contact restrictions in schools, workplaces, and other community settings, evaluating projected severe-case demand against an illustrative healthcare-capacity benchmark. Vaccination combined with workplace and community contact restrictions keeps simulated demand within capacity. In contrast, relaxing restrictions in either setting produces large surges and repeated capacity threats, even when school restrictions remain. School-only changes produce smaller effects on severe disease. These findings highlight the value of vaccination and setting-specific contact restrictions that prioritize workplace and community settings for pathogens with adult-concentrated severe outcomes.

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Source-linked multispecialty clinical reasoning and tumour-board decision-making in colorectal cancer

Gombolevskiy, V. A.; Sekacheva, M. I.; Sanikovich, V. D.; Bagmet, N. N.; Balaeva, D. A.; Nechaev, N. B.; Nesterov, A. I.; Bokov, A. A.; Panin, I. I.; Bespalov, I. R.; Gribakina, A. V.; Dylov, D. V.; Oseledets, I. V.

2026-10-21 oncology 10.64898/2026.10.19.26365647 medRxiv
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Clinical records preserve patient findings and final recommendations but rarely capture how specialists select evidence, develop alternative interpretations, disagree, and converge on a management strategy. We describe a dataset derived from ten retrospectively selected, completed cases of histologically confirmed colorectal cancer. For each case, an administrator uploaded de-identified textual clinical records to an authenticated web-based annotation platform. A medical oncologist, surgical oncologist, and radiation oncologist, each with more than ten years of clinical experience, independently linked relevant source fragments to patient-specific interpretations and documented clinical problems, differential hypotheses, uncertainty, and diagnostic and treatment strategies. After the three records were locked, a large language model generated candidate questions for review by the tumour-board chair. The four physicians then discussed each case online; recordings were automatically transcribed and verified by two medical residents. The dataset comprises 30 source-linked specialist reasoning records, 10 verified case-level discussion transcripts, 10 final tumour-board decisions, and associated provenance and quality-control metadata. It supports research on evidence-grounded reasoning, cross-specialty disagreement, multidisciplinary decision-making, and multi-agent clinical decision support.

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Factors Associated with Divergent Introgression Outcomes from Wolbachia-Based Interventions in Rio de Janeiro, Brazil

Nelson, E.; Carcamo, P. M.; Ribeiro dos Santos, G.; Sylvestre Ribeiro, G.; Rodrigues da Costa, T.; Ilaria Dorigatti, I.; Salje, H.; Moreira, L. A.; Cummings, D. A. T.; Ko, A. I.

2026-10-21 infectious diseases 10.64898/2026.10.16.26365711 medRxiv
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Wolbachia-based interventions were less effective in achieving introgression in Rio de Janeiro than other settings. Reduced introgression occurred in locations where dengue was historically high, raising concerns of inequity. We examined factors affecting Wolbachia introgression in Rio through trajectory modeling, spatiotemporal Bayesian models, and Ae. aegypti abundance estimation. During the intervention (2017-2020), Wolbachia introgression was 26% (median; IQR,14-44%), with four distinct trajectories. Despite receiving more releases, densely populated areas with low socioeconomic status had lower introgression. In spatiotemporally explicit multivariable regressions, higher Ae. aegypti abundance, temperature, population density and lower socioeconomic status were associated with reduced introgression. Improved characterization of Ae. aegypti abundance and other structural/environmental predictors of introgression could be used to calibrate release doses to ensure equitable benefits from Wolbachia interventions.

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Patient Perceptions of Student Involvement and Satisfaction in a Student-Run Free Clinic Serving People Experiencing Homelessness

Joe, M. K.; Kamepalli, S.; Hoffman, K. W.; Cumming, A.; Babcock, L. L.; Noltensmeyer, D. A.; Balaji, S.; Bigham, C. G.; King, B. T.; Altman, M.; Pillow, M. T.; McCurry, V.; Clark, D. L.

2026-10-15 health systems and quality improvement 10.64898/2026.10.13.26365447 medRxiv
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Background: Patient satisfaction is a key measure of healthcare quality among people experiencing homelessness. Student-run free clinics (SRFCs) provide care to underserved populations, but the role of student involvement in patient satisfaction remains unclear. Methods: We conducted a cross-sectional study of patients receiving care at an SRFC. From February 2024 to February 2025, patients completed post-visit surveys assessing satisfaction that were evaluated using regression analyses. Results: Eighty-eight patients completed surveys, reporting high overall satisfaction (mean 9.26/10). In separate linear regression models adjusted for age, gender, and race, greater perceived benefit of student involvement was associated with higher satisfaction ({beta} = .298, p = .037), whereas perceiving the visit as too long was associated with lower satisfaction ({beta} = -.285, p = .019). Conclusion: Greater perceived benefit of student involvement was associated with higher patient satisfaction, whereas longer perceived visit duration was associated with lower satisfaction. These findings highlight the importance of balancing educational opportunities with efficient workflows in SRFCs.

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Cost-Effectiveness of Expanding Housing Access for People Experiencing Homelessness and Opioid Use Disorder in California

Ling, Y.; Tsung, S.; Alarid-Escudero, F.; Goldhaber-Fiebert, J. D.; Brandeau, M. L.; Reitsma, M. B.

2026-10-19 health policy 10.64898/2026.10.15.26365505 medRxiv
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People experiencing homelessness (PEH) have substantially lower quality-adjusted life expectancy and substantially higher healthcare spending compared to housed populations. California has the largest population of PEH in the United States, and an estimated ten percent of PEH have co-occurring opioid use disorder (OUD). We developed a lifetime, individual-level microsimulation of the 18,928 PEH with OUD in California to evaluate the health and economic effects of expanding access to housing through a Housing First approach, which does not require OUD treatment or abstinence. Increases in permanent housing and shelter access were based on Los Angeles County's Measure A goals, and we accounted for both housing and healthcare costs. Expanding housing access increased mean age at death by 0.34 years, reduced fatal overdoses for the cohort by 39, and produced an incremental cost-effectiveness ratio of $31,083 per quality-adjusted life-year gained, well below conventional willingness-to-pay thresholds. We provide evidence that housing is a high-value health intervention for PEH with OUD in California. Policymakers should support Housing First programs as part of integrated responses to the intertwined crises of homelessness and opioid use.

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Medical and non-medical out-of-pocket cost and time burden of COVID-19 illness in U.S. children and adults: a cross-sectional survey study

Rose, A.; Scherer, A.; Gedlinske, A.; Park, A.; Gidengil, C.; Askelson, N.; Lindley, M.; Gebremariam, A.; Pike, J.; Prosser, L.

2026-10-15 health economics 10.64898/2026.10.14.26365534 medRxiv
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Background: While health system costs of COVID-19 are well documented, evidence on out-of-pocket costs to patients and families, including non-medical and time burden, is limited. This study aimed to estimate out-of-pocket medical, non-medical, and time burden of COVID-19 illness directly from patients and caregivers. Methods: Two cross-sectional surveys were fielded to national nonprobability samples of U.S. adults in Fall 2023: a personal burden survey (adult sample) and a caregiver burden survey (child sample). Surveys collected data on care setting, visit duration including travel and wait time, and medical and non-medical out-of-pocket costs. After applying quality-based exclusion criteria, 409 adult sample and 52 child sample responses were analyzed. Results: Over 87% of respondents were insured. Median out-of-pocket medical costs per visit were low, ranging from $5 (emergency department) to $10 (urgent care) in the adult sample, and from $0 (emergency department) to $75 (hospitalization) in the child sample. Median non-medical costs were $28 or less across care settings. Median time spent receiving care ranged from 90 minutes (primary care, child sample) to 300 minutes (emergency department, adult sample). Despite the relatively low reported out-of-pocket costs, COVID-related financial challenges were reported by 34% of the adult sample and 29% of the child sample, with the most common difficulty being paying non-medical bills (11% and 15%, respectively). Twelve percent in both groups reported problems paying COVID-19-related medical bills. Conclusions: In this post-pandemic non-probability sample, individual out-of-pocket costs for COVID-19 illness were relatively modest. However, time burden was substantial and one-third of respondents reported financial hardship. These estimates, including non-medical and time burden not captured in administrative data, can support more robust economic evaluations of COVID-19 prevention and treatment interventions.

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Reconstructing Dengue Exposure Dynamics and Assessing the Public Health Impact of Vaccination Scenarios Using Mathematical Models in Brazil

Ko, Y.; Santos, C.; Huang, A. T.; Salje, H.; Cummings, D. A.; Ko, A. I.

2026-10-16 epidemiology 10.64898/2026.10.15.26365586 medRxiv
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Brazil experienced its worst dengue epidemic in 2024, with an increase in severe outcomes among elderly individuals, highlighting the need for vaccination strategies informed by population immunity. We reconstructed state- and age-specific immune profiles by fitting an age-structured catalytic model to dengue surveillance data from 2000-2025. This inferred immune profile was incorporated into an SIR-type transmission model to project disease burden and to evaluate the public health impact of vaccine allocation strategies. We observed substantial spatial heterogeneity in accumulated immunity, which was closely associated with projected burden and optimal allocation. Strategies prioritizing states with lower historical incidence and larger susceptible populations yielded greater benefits. Under limited vaccine supply, targeting children resulted in the greatest reductions in DALYs, whereas targeting elderly populations achieved smaller DALY reductions but larger reductions in mortality. We further showed that accelerated vaccine supply markedly increased impact, while allocation choices remained critical when availability was constrained.

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Does the Disease-free Survival Benefit of Adding Belzutifan to Adjuvant Pembrolizumab Persist Beyond the Planned Treatment Period? A Reconstructed Individual Patient Data Analysis of Phase 3 Renal Cell Carcinoma Trials

Chang, H.-H.; Chang, C.-K.; Tang, T.-Y.; Jhan, J.-H.; Dong, S.-W.; Juan, Y.-S.; Geng, J.-H.; Ou, H.-C.; Lee, H.-Y.; Li, C.-Y.; Yeh, H.-C.; Leong, M.-K.; Liu, C.-H.; Lee, Y.-C.; Huang, S.-P.

2026-10-16 oncology 10.64898/2026.10.14.26365591 medRxiv
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Background and Objective: Adding belzutifan to adjuvant pembrolizumab improved disease-free survival (DFS) in LITESPARK-022, but its durability beyond the 1-year treatment is unknown. Methods: Following a registered plan, we reconstructed individual patient data from published Kaplan-Meier curves of ten phase 3 adjuvant renal cell carcinoma trials. Within each trial, we estimated restricted mean survival time differences ({Delta}RMST), hazard ratios (HRs) before and after planned treatment ended, and DFS differences. Key Findings and Limitations: In LITESPARK-022 (central review), the 24-month {Delta}RMST was 1.34 months (95% confidence interval 0.73-1.95), and the belzutifan arm remained ahead after month 12 ({Delta}RMST increment 0.74 months/yr, 0.32-1.19). The HR was 0.55 (0.43-0.71) before month 12 and 1.16 (0.87-1.54) afterwards (post/pre ratio 2.10); investigator assessment showed similar attenuation. Similar ratios occurred in KEYNOTE-564 at its first interim analysis (2.02), whose benefit persisted, and in SORCE and PROTECT (2.09, 2.59), whose benefit faded. From months 12 to 30 (post hoc), the DFS difference changed by -3.7 percentage points (-8.1 to 0.8) with central review and 0.6 (-4.0 to 5.0) with investigator assessment. Data were reconstructed, and follow-up was short. Conclusions and Clinical Implications: Relative hazard reductions with belzutifan were greater before month 12; durability of the absolute DFS advantage is uncertain and assessment-dependent, so single-HR projections should be avoided.

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First-in-human trial in Burkinabe adults and children of replication-competent, genetically attenuated PfSPZ-LARC2 Vaccine for malaria

Sirima, S. B.; Richie, T. L.; Ouedraogo, A.; Soulama, B. I.; Zou, A. R.; Nebie, I.; KC, N.; Camargo, N.; Goswami, D.; Kabore, J. M. T.; Kirakoya, N.; Mbaiasra, R. K.; Ezinmegnon, S.; Badoum, E. S.; Ouedraogo, S. Y.; Henry, N. B.; Yaro, J. B.; Mabuka, T.; Murshedkar, T.; Abebe, Y.; Perez, D.; James, E. R.; Minkah, N.; Vaughan, A. M.; Laurens, M. B.; Sim, B. K. L.; Kappe, S. H. I.; Tiono, A. B.; Hoffman, S. L.

2026-10-21 infectious diseases 10.64898/2026.10.16.26365330 medRxiv
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The World Health Organization has called for malaria vaccines with > 90% efficacy against Plasmodium falciparum (Pf) infection. The live, non-attenuated PfSPZ-CVac (chloroquine) vaccine provides the strongest protection against controlled human malaria infection (CHMI). Its 100% protective efficacy at 12 weeks against genetically distant Pf stems from a highly amplified immune stimulus. After inoculation, each invading sporozoite (SPZ) replicates up to 50,000 times within a hepatocyte. Over six days of development, these parasites express thousands of distinct proteins, presenting a vast and diverse array of antigens to the host immune system. The late liver stage parasites then rupture into the bloodstream, where they are killed by the co-administered drug, chloroquine. To engineer a Pf parasite that develops to the late liver stage like PfSPZ-CVac (chloroquine), but then arrests before transitioning to the blood stage, two genes required for transition from non-pathogenic liver to pathogenic blood stages were identified and deleted, creating late-liver stage arresting, replication-competent (LARC) PfSPZ. In a first-in-human, randomized, double-blind, placebo-controlled clinical trial, we assessed PfSPZ-LARC2 Vaccine in 75 malaria-exposed Burkinabe 1- to 48-year-olds. No vaccine-strain breakthrough blood-stage infections were detected; safety and tolerability profiles were similar in vaccinees and placebo recipients; and the highest immunogenicity was observed in the youngest recipients. Based on these findings, PfSPZ-LARC2 Vaccine has progressed to Phase 2 testing with the goal of rapidly advancing this genetically attenuated whole parasite vaccine to licensure and deployment.

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Mapping county-level tick-borne disease risk in Illinois by integrating vector abundance, pathogen prevalence, and phenology

Hussain, A.; Bhowmick, S.; Mateus-Pinilla, N.; Smith, R. L.

2026-10-16 epidemiology 10.64898/2026.10.14.26365569 medRxiv
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Tick-borne disease risk reflects the combined influence of vector abundance, pathogen prevalence, human exposure, and seasonal activity, yet these components are rarely integrated at the county level. We developed species-specific ecological risk scores for three medically important tick species (Acari: Ixodidae): Amblyomma americanum (L.), Dermacentor variabilis (Say), and Ixodes scapularis Say, across all 102 Illinois counties using data from 2019 to 2022. County-level predicted tick abundance and pathogen prevalence were scaled and combined using equal weights to generate primary vector-level risk scores. Robustness to the equal-weight assumption was evaluated by systematically varying the relative weights assigned to abundance and pathogen prevalence, while a separate sensitivity analysis incorporated reported tick-bite incidence where available. Associations with human disease were evaluated using negative binomial regression of tick-borne disease case counts on the corresponding risk scores, with county population included as an offset. Monthly phenology indicators were constructed by integrating human disease cases, reported tick bites, and sampled tick abundance and were evaluated in relation to temperature and precipitation. Seasonal risk was estimated by combining county-level vector risk with species-specific monthly phenology, generating monthly risk surfaces that were deployed through an interactive R Shiny application. Higher risk scores were significantly associated with greater disease case rates for each tick species. County rankings were highly stable under moderate changes in abundance and prevalence weighting. Seasonal activity differed among species, with A. americanum and D. variabilis showing concentrated warm-season risk and I. scapularis exhibiting a broader seasonal profile. These county-level seasonal risk maps identify where and when relative tick-borne disease risk is elevated in Illinois, supporting targeted prevention, surveillance, and clinical awareness.

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Return Visits, Admission, and Mortality After Leaving Without Being Seen Among Emergency Department Patients With Behavioral HealthPresentations

Ashoo, S.; Peacock, W. F.; Colovos, C.

2026-10-20 emergency medicine 10.64898/2026.10.14.26365554 medRxiv
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Abstract Importance Patients with behavioral health presentations leave the emergency department (ED) before evaluation more often than other patients, but outcomes after leaving without being seen (LWBS) have not been described in this population. Objective To compare return visits, admission, and mortality after LWBS vs completed care among behavioral health ED episodes. Design, Setting, and Participants This retrospective episode-level cohort study used a multisystem deidentified electronic health record database of US health systems (data snapshot June 4, 2026). Participants were patients of all ages with an ED visit and same-day behavioral health diagnosis. Index visits (recorded January 26, 2001 to April 13, 2025) each opened a 30-day episode window; in-window were counted as outcomes, and patients could contribute episodes to either group. Data were analyzed in October 2026. Exposure LWBS (diagnosis code Z53.21 on a date with an ED encounter) vs completed care ending in discharge home. Main Outcomes and Measures The primary outcome was ED return visit within 7 days. Secondary outcomes were return visit within 3 and 30 days; admission on day 0, on days 1-7 (principal measure), and within 30 days; and all-cause death within 7 and 30 days, assessed among episodes from 2017 through 2023 using a verified death-record definition. Results The analysis included 1,305,812 episodes (12,248 LWBS; 1,293,564 completed care) from 525,490 patients; 666,930 episodes (51.1%) involved female patients and 66,733 (5.1%) involved patients younger than 18 years. Return visit within 7 days followed 24.5% of LWBS episodes vs 13.2% of completed-care episodes (risk ratio [RR], 1.86; 95% CI, 1.81-1.92), and admission on days 1-7 followed 17.1% vs 3.9% (RR, 4.41; 95% CI, 4.24-4.59). Among 2017-2023 episodes, 30-day mortality was 0.69% (70 of 10,141) after LWBS vs 0.32% (2,426 of 756,140) after completed care (RR, 2.15; 95% CI, 1.70-2.73). Results were similar under alternative episode definitions. Conclusions and Relevance Among patients with behavioral health ED presentations, LWBS was followed by higher rates of return visits, admission, and short-term mortality than completed care. These unadjusted findings describe outcome burden, not causal effects, and highlight patients who leave as a target for rapid follow-up.

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Real-world perioperative FLOT delivery in gastric and gastro-oesophageal junction adenocarcinoma: a single-centre service evaluation in a District General Hospital in the UK

Sabharwal, R.; Bhaskaran, D.

2026-10-21 oncology 10.64898/2026.10.19.26365836 medRxiv
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Background: Although perioperative fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) is the standard neoadjuvant regimen for resectable gastric and gastro-oesophageal junction adenocarcinoma, evidence describing treatment delivery in routine clinical practice remains limited, particularly regarding relative dose intensity (RDI) and treatment completion. Objectives: To evaluate real-world delivery of preoperative FLOT chemotherapy, including treatment completion, progression to surgery, RDI, toxicity and exploratory changes in estimated lean body mass (LBM). Methods: A retrospective single-centre service evaluation included consecutive patients receiving neoadjuvant FLOT during 2024. Outcomes included treatment completion, surgery, RDI, toxicity, pathological response and estimated LBM. Descriptive statistics were used. Results: Twelve patients were included (median age 68.6 years; 91.7% male). Eleven (91.6%) completed all four preoperative cycles and proceeded to surgery. Mean RDI was 76.7%. Pre-emptive dose capping was the predominant dose modification strategy, with only one reactive dose reduction. Two grade 3 adverse events occurred. Major pathological response (Mandard grade 1-2) was observed in 2/12 patients (16.7%). Mean estimated LBM declined from 54.3 to 53.4 kg. Greater LBM loss appeared to coincide with poorer clinical outcomes. Conclusions: High treatment completion and progression to surgery were achieved despite reduced RDI. These findings support prospective evaluation of strategies to optimise chemotherapy delivery while maintaining tolerability in routine clinical practice.

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Quantifying optimal AWaRe antibiotic use patterns in hospitals with a new benchmarking tool applied to cross-sectional point prevalence survey data from 10 countries

Swe, M. M. M.; Pauwel, I.; Costa, S. F.; Porto, A. P. M.; Reyes, M. R. D. L.; Garcia, J.; Soltani, J.; Banda, D. C.; Rachina, S.; Belkova, Y.; Maldonado, H.; Lopicic, M.; Raicevic, M.; Vlieghe, E.; Versporten, A.; Sharland, M.; Cooper, B. S.; Lim, C.; The Adila Consortium, ; The Global-PPS network,

2026-10-15 public and global health 10.64898/2026.10.12.26363793 medRxiv
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Background: Both over- and under-antibiotic use pose major global health challenges, yet there is no consensus on how to quantify deviations from optimal prescribing or set evidence-based targets. We developed a benchmarking tool for inpatient antibiotic use and evaluated its application in 10 countries. Methods: We developed decision-tree models to estimate expected empiric antibiotic use for 11 indications, based on the WHO AWaRe book for two age groups: 28 days to 12 years and >12 years. We parameterised the models using country-specific antimicrobial resistance estimates in the 10 countries and cross-sectional Global Point Prevalence Survey (Global-PPS) case-mix data from 2021 for 10 countries and from 2015-2022 in a subset of five countries. We then compared estimated expected antibiotic use with observed empiric use (from Global-PPS) in defined daily doses for adults and days of therapy for children, across indications and AWaRe categories. Findings: In 2021, among patients aged >12 years, in all countries but one, observed empiric Access antibiotic use, as a proportion of total antibiotic use, was lower than expected and empiric Watch antibiotic use was higher than expected. Similar patterns were observed in all countries but one in patients aged 28 days to 12 years. The magnitude of discrepancies between expected and observed Access and Watch antibiotic use varied across indications and countries. The median observed-to-expected ratios of usage across countries ranged from 0.3-0.8 for Access antibiotics, and 0.7-5.3 for Watch antibiotics in patients aged >12 years in 2021. Temporal trends from repeated surveys from 2015 to 2022 showed little change in observed-to-expected ratios for Access and Watch antibiotics. Interpretation: This benchmarking tool uses Global-PPS data to quantify differences between observed antibiotic use and WHO AWaRe recommendations. Our tool can be adaptable to local guidelines, provides policy-relevant estimates of expected antibiotic use to support monitoring, procurement planning, and targeted stewardship intervention.

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Impact of anemia on length of hospital stay among patients hospitalized for severe malaria in Brazzaville, Republic of the Congo

Ekat, M. H.; Amona, M.; Andzi Barre, M.; Bendett Lebaho, P.; Aloumba, G. A.; Adoua Doukaga, T.

2026-10-16 infectious diseases 10.64898/2026.10.14.26365597 medRxiv
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Background: Severe malaria remains a major cause of hospitalization in malaria-endemic sub-Saharan Africa, and anemia is among its most frequent severity criteria. Data on the impact of anemia on hospital length of stay (LOS) among adults with severe malaria remain limited in Central Africa. We assessed the impact of anemia on LOS among adults hospitalized for severe malaria in Brazzaville, Republic of Congo. Methods: We conducted a cross-sectional, descriptive, and analytic study of medical records from adult patients ([&ge;]18 years) diagnosed with severe malaria (WHO criteria) and admitted to four hospitals in Brazzaville between January 2020 and December 2024. We dichotomized LOS as short (<5 days) or prolonged ([&ge;]5 days). Multivariable logistic regression, using a backward stepwise procedure, identified factors independently associated with prolonged LOS; isolated hemoglobinuria served as the reference severity category. Results: Among 523 patients hospitalized for severe malaria, 296 met the inclusion criteria. Median age was 25.5 years (IQR 20-40); 51.7% were female, and 82.1% had a low socioeconomic status. Median hemoglobin was 10.55 g/dL, and median LOS was 4 days (IQR 3-5). In multivariable analysis, prolonged LOS was independently associated with delay to consultation (aOR 1.25/day, 95% CI 1.09-1.44), isolated anemia (aOR 7.07, 1.23-40.55), convulsions (aOR 5.86, 1.81-18.97), prostration (aOR 4.42, 1.21-16.2), and impaired consciousness (aOR 4.29, 1.17-15.7). The strongest associations involved combined severity criteria: anemia with prostration (aOR 8.58), anemia with jaundice or hemoglobinuria (aOR 16.21), and impaired consciousness with anemia (aOR 33.31). Conclusions: Anemia is a major, potentially modifiable determinant of prolonged hospitalization in adults with severe malaria, with a markedly amplified effect when combined with neurologic impairment. Early anemia screening, improved access to safe blood transfusion, and reduced delays to care could shorten hospital stays and ease the burden on health systems in this setting.