Back

COVID

○ MDPI AG

Preprints posted in the last 7 days, ranked by how well they match COVID's content profile, based on 14 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
SARS-CoV-2 infection detection efficiency in Denmark before major vaccine impacts

Westfall, M. N.; Hoiby, N.; Rasmussen, S.; Ziock, H.-J.

2026-10-21 epidemiology 10.64898/2026.10.16.26364986 medRxiv
Top 0.5%
0.8%
Show abstract

To deal with the COVID-19 pandemic, Denmark implemented an aggressive program aimed at controlling the pandemic which included both testing and contact tracing programs. The large amount of data collected in Denmark on the pandemic and its integrated nature made it possible to investigate the effectiveness of the testing and contact tracing effort. The results of that investigation and a discussion of the effectiveness and limitations of the different control efforts are reported herein, as are lessons learned concerning possible improvements for the future. The analysis is limited to the period from the start of the COVID-19 pandemic in Denmark (late Feb. 2020) into May 2021, at which time the impact of vaccination intervention was already playing a role with ~25% of the Danish population at least partially vaccinated. From the available data sets we estimate the national Infection Detection Efficiency (IDE) starting around July 1, 2020, the time at which the national infection detection program started to be implemented in a more robust form. The results rely on daily COVID-19 hospital admissions, PCR test results, and anti-body prevalence values for the Danish population. We find that for the long-term average, the combined Danish national testing and contact tracing program identified on average about 55 to 60% of the infected individuals during the period from Sept. 1, 2020, into early May 2021. However, higher infection detection efficiencies were achieved in localized areas for short time intervals. Our investigations further indicate that the Danish testing and contact tracing program, which was among the most ambitious in the world, could have had a better balance between voluntary probing on the one hand and focused contact tracing and targeted testing on the other hand. As typically implemented, it proved to be largely ineffective in controlling the pandemic. However, in at least one case when it was implemented in an enhanced and focused mode, it was able to bring a large local outbreak that dominated the country's cases under control. We have compiled a list of lessons learned regarding the use of contact tracing procedures to control potential future pandemics before vaccinations become available.

2
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
Top 1%
0.4%
Show abstract

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.

3
Ebola Disease Knowledge and Vaccine Acceptance in the Democratic Republic of the Congo

Merritt, S.; Kindrachuk, J.; Nkamba, D.; Hoff, N. A.; Kalengi, H.; Halbrook, M.; Kamba, L.; Beya, M.; Petrichko, S.; Wallace, H. L.; Luhata, C.; Kaba, D.; Rimoin, A. W.

2026-10-19 public and global health 10.64898/2026.10.15.26365673 medRxiv
Top 2%
0.2%
Show abstract

We report general acceptance (79.0%) of Ebola vaccination in the Democratic Republic of the Congo (DRC) between 2023-2024 (n=5,062). Acceptance varied significantly by province with acceptance ranging from 47.6% in Kongo Central to 92.1% in Tshuapa province and was highest among healthcare workers. While Ebola vaccine acceptance and disease knowledge are relatively strong nationally in the DRC, regional differences do exist and may impact future vaccine rollout.

4
Modelling the health and budget impact of introducing diphtheria-tetanus-pertussis-containing-vaccine booster doses in Uganda

Hounsell, R.; Silal, S. P.; Norman, J.; Monyake, R.; Immaculate, A.; Besigye, A.; Biroma, G.; Magoola, J.; Kishore, N.; Pallas, S. E.; Ward, K.

2026-10-20 public and global health 10.64898/2026.10.15.26365602 medRxiv
Top 2%
0.2%
Show abstract

Routine infant vaccination has helped reduce cases and deaths from diphtheria, tetanus, and pertussis globally. However, these diseases continue to pose serious health risks as protective immunity wanes over time. Three booster doses of diphtheria-tetanus-pertussis-containing vaccine (DTPCV) administered from 12-months to 15-years of age increase duration of protection beyond childhood. Growing demands on government health spending underscore the importance of understanding the health and economic impact of vaccines prior to introduction. Using an integrated multi-disease epidemiological-economic model, we estimated the health impact (cases averted, deaths averted, and changes to population immunity) and budget impact of introducing DTPCV booster doses in Uganda. Compared to no DTPCV boosters, introducing all three booster doses is projected to result in 2.2 times the proportion of the population protected against symptomatic diphtheria and 2.8 times against tetanus infection among Ugandans under 15 years of age by 2039. Compared to introduction of the early childhood booster (EC) at 18 months of age, introducing all three DTPCV boosters simultaneously is projected to avert 3.2 times the number of tetanus cases over fifteen years at 2.4 times the incremental cost. The projected government vaccination cost per planned dose was USD 0.58 for simultaneous introduction of all three boosters compared with USD 0.68 for the EC booster alone. The average annual incremental cost of all three DTPCV booster doses is USD 2.79 million. Under modelled assumptions, simultaneous introduction of all three DTPCV booster doses in Uganda provides the greatest health gains, with a lower government vaccination cost per planned dose than introduction of the EC booster alone, but may still pose affordability challenges for Ugandas government.

5
Swiss physicians' experiences of sexual harassment at work. A nationwide survey

Dzi, K. T.; Jox, R.; Bodenmann, P.

2026-10-21 public and global health 10.64898/2026.10.19.26365908 medRxiv
Top 2%
0.2%
Show abstract

Background: Workplace discrimination and violence against health workers including sexual harassment is a societal problem worldwide. We aimed to assess the frequency, predictive factors, and effects of sexual harassment using a nationwide survey of physicians working in Switzerland. Materials and Methods: We conducted a self-administered questionnaire survey of physicians working in Swiss healthcare institutions. The questionnaire assessed experiences of sexual harassment at work, including frequency, types, and sources of harassment. It also asked about the impact of sexual harassment, whether incidents were reported, and what actions were taken following a report. Results: Among the 1837 physicians that participated in the survey, 575 (31.3%) had experienced sexual harassment at least once during their career. Among those reporting sexual harassment, 39.1% of women and 13.2% of men had experienced harassment at least once in their job. Women reported more verbal harassment, while men reported more physical harassment. Women were also more likely to face both forms combined. The main sources of harassment were colleagues of the same profession (46.7%), patients (42.3%), and superiors (41.0%). The most frequently reported impacts included stress (60.1%), emotional exhaustion (34.7%), reduced motivation at work (30%), and considering leaving the job (7.5%). Gender-men was associated with a lower likelihood of experiencing harassment 0.24 (0.18 to 0.31), whereas working in the German-speaking region was associated with a slightly higher likelihood of having experienced sexual harassment at least once (OR 1.35, 95% CI:1.02-1.81). Conclusions: Sexual harassment is common among physicians in Swiss healthcare institutions. It adversely affects the mental health and career trajectories of both men and women yet remains widely underreported due to fears of reprisals and inaction. Institutions should effectively intervene to ensure that reported incidents result in appropriate actions, and that those who report them receive adequate protection from reprisals.

6
Gender-based violence rates and mental health disease burden in India, 2001-2021: A state-level ecological study

Sangekar, S.; Baranyi, G.; Kirkbride, J. B.; Patalay, P.

2026-10-19 public and global health 10.64898/2026.10.16.26365723 medRxiv
Top 2%
0.2%
Show abstract

Violence against women is a key contributor to mental health gender disparities, with greater gender gaps observed in low-and middle-income countries. This study examines state-level associations between gender-based violence against women and mental health burden in India over time. We linked 1) annual state-level age-standardised disability-adjusted life year rates (ASDR) from the Global Burden of Disease study for overall mental health disorders, depressive disorders, anxiety disorders, bipolar disorder, schizophrenia and self-harm, with 2) annual state-level gender-based violence rates from the Open Government Data Platform, India. We used descriptive ecological analyses and multilevel modelling to estimate the state-level association between gender-based violence and sex-stratified mental health outcomes over time (2001 - 2021). Results showed higher state-level gender-based violence (GBV) rates were associated with higher state-level ASDR of schizophrenia ({beta}women = 0.39 [95%CI 0.25 - 0.52]; {beta}men = 0.42 [0.29 - 0.55]) and bipolar disorder ({beta}women = 0.02 [0.01- 0.03]; {beta}men = 0.04 [0.03 - 0.05]), after adjustment for state-level social development, but not with other outcomes. Higher GBV rates were associated with a lower gender disparity in depressive disorders. Longitudinal findings revealed that the state-level association between GBV rates and ASDR of overall mental health disorders strengthened over time ({beta}women = 5.08 [3.96 - 6.20]; {beta}men = 3.38 [2.60 - 4.15]), whereas the association weakened for self-harm and schizophrenia. Lagged findings suggested that with an increase in GBV rate, ASDR of overall mental health disorders increased for men over two years and for both sexes over five years. Our findings highlight the importance of considering state-level trends in GBV and related policies, and considering impacts of GBV on both men and women's mental health.

7
Interactions between respiratory viruses in US adults and children: a prospective cohort study

Hoffman, K. L.; Weil, A. A.; Wetzler, E. A.; Akinola, B. O.; Beauge, A.; Andy, C.; Adams, A.; Frivold, C.; Cox, S. N.; Ehmen, B.; Hatchie, T.; Clark, E. L.; Drummond, M.; Englund, J.; Han, P. D.; Kuntz, J. L.; Lo, N. C.; Lockwood, C.; Starita, L.; Mularski, R. A.; Naleway, A. L.; Carone, M.; Chu, H. Y.

2026-10-19 infectious diseases 10.64898/2026.10.15.26365672 medRxiv
Top 3%
0.1%
Show abstract

Background: The relationship between recent viral infection and subsequent susceptibility to, or protection against, other viruses remains unclear, particularly across ages and symptom status. Methods: A prospective cohort study enrolled participants aged 6 months to 49 years in Washington and Oregon, USA, 2022-2024. Weekly nasal swabs were tested for SARS-CoV-2, respiratory syncytial virus (RSV), and influenza A/B; additional swabs were collected during symptomatic illness and were also tested for parainfluenza (PIV) 1-4, endemic human coronaviruses (hCOV), adenovirus, human metapneumovirus, human rhinovirus (hRV), and enteroviruses. Proportional hazards regression models were used to characterize associations between incident symptomatic infection (illness) and history of recent illness due to other viruses (within 1-7, 8-14, 15-30, 31-60, 61-90, 91-180 days), adjusted for geographic region, age, sex, daycare/school/work attendance, household size, and number of children in the household. For SARS-CoV-2, influenza, and RSV, these analyses were repeated to study incidence of infection (including asymptomatic cases). Findings: Of 3,560 participants, 2,969 (83%) had [≥]1 illness over 4,299 person-years. Adjusted hazard ratios (aHRs) in the short term ([≤]2 weeks) after an illness were predominantly below 1, indicating that recent viral illness was often associated with lower risk of subsequent illness with other viruses. Across age groups, recent hRV illness was associated with lower risk of hCOV, PIV, and RSV illness (aHRs 0.07-0.27). SARS-CoV-2 illness was associated with a higher short-term risk of adenovirus and PIV illness (aHRs 3.20-3.33). In children aged 6 months-4 years, recent influenza illness was associated with higher short-term risk of SARS-CoV-2 illness. Including asymptomatic infections generally attenuated these associations. Interpretation: Some viral illnesses may alter short-term susceptibility to subsequent viral illnesses. Interactions may differ by age and symptom status. Funding: US Centers for Disease Control and Prevention; Washington State Department of Health.

8
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
Top 3%
0.1%
Show abstract

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.

9
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
Top 3%
0.1%
Show abstract

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.

10
Burden and factors associated with hospitalization among patients with chronic Diseases at a tertiary Hospital in Wolaita Zone, South Ethiopia: A Cross-sectional study

Koyra, H. C.; Belete, Y. W.; Kanche, Z. Z.; Desalegn, Z.; Koyra, M. M.

2026-10-16 public and global health 10.64898/2026.10.14.26365506 medRxiv
Top 3%
0.1%
Show abstract

Background Chronic diseases are the leading causes of illness, disability, and death worldwide, with a disproportionate burden in low- and middle-income countries. Hospitalization is a critical outcome in chronic disease management, reflecting disease severity, treatment failure, and healthcare utilization. However, data on hospitalization burden and its associated factors among chronic disease patients in Ethiopia, are limited. This study aimed to determine the rate of hospitalization and its associated factors among patients with chronic diseases attending a tertiary hospital in Wolaita Zone, South Ethiopia. Methods A facility-based cross-sectional study was conducted among 321 patients with chronic diseases attending the chronic follow-up clinic at Wolaita Sodo University Comprehensive Specialized Hospital from November to December 2022. Consecutive recruitment was used, with unique medical record numbers tracked to prevent double recruitment. Data were collected through structured questionnaires and medical record review. Negative binomial regression was used to identify factors associated with hospitalization rate, with incidence rate ratios (IRR) and 95% confidence intervals (CI) reported. A p-value < 0.05 was considered statistically significant. Results Of the 321 participants, 66% reported at least one hospitalization while on treatment, with a mean of 1.70 {+/-} 1.81 hospitalizations per patient. Drug discontinuation was the most frequently documented reason for hospitalization (39.5%), followed by disease complications (22.3%) and infections (11.7%). Multimorbidity was prevalent, with the majority (59.8%) had 2-3 conditions, and a mean of 2.40 {+/-} 1.02 chronic diseases per patient. Male sex was associated with a higher hospitalization rate, while regular physical exercise was associated with a lower number of hospitalizations. Conclusion This study found a high burden of hospitalization among chronic disease patients, with drug discontinuation being the leading documented reason. Male sex and regular physical exercise were significantly associated highlighting the need for medication adherence support programs and structured exercise programs integrated into routine chronic disease care, as well as gender-sensitive interventions.

11
Roles, Challenges, and Solutions for Maternal and Child Health in rural Communities in Bangladesh

Abdullah, A. S.; Halim, A.; Haq, F.; Sayem, A. S. M.; Dalal, K.

2026-10-21 public and global health 10.64898/2026.10.18.26365859 medRxiv
Top 3%
0.1%
Show abstract

Background Despite substantial improvements in maternal and child health over the past two decades, preventable maternal and neonatal morbidity and mortality remain major public health concerns in rural Bangladesh. Community-based interventions involving Community Volunteers (CVs), Community Groups (CGs), and Community Support Groups (CSGs) have been introduced to strengthen maternal and child health (MCH) services through health promotion, community engagement, and improved linkage with primary healthcare facilities. This study explored the roles, challenges, and opportunities of these community-based platforms in improving maternal and child health services. Methods A qualitative study was conducted in Kalaroa Upazila of Satkhira District, Bangladesh, between July and October 2020. Data were collected through focus group discussions and in-depth interviews with mothers, Community Volunteers, Community Group members, and Community Support Group members. Participants were purposively selected to capture diverse experiences from intervention and comparison areas. Interviews were conducted using semi-structured guides, audio-recorded with informed consent, transcribed verbatim, translated into English, and analyzed thematically using an inductive approach. Results Participants from intervention areas demonstrated greater knowledge of birth preparedness, antenatal care, pregnancy danger signs, institutional delivery, postnatal care, and newborn care than those from comparison areas. Community Volunteers, CGs, and CSGs played important roles in identifying pregnant women, conducting household counselling, promoting skilled maternal healthcare, facilitating referrals, and strengthening community participation. Participants perceived that these activities increased maternal awareness, improved health-seeking behaviour, and enhanced utilization of maternal and newborn health services. However, persistent barriers, including socio-cultural beliefs, financial constraints, transportation difficulties, shortages of skilled healthcare providers, and inadequate logistical support for community volunteers, continued to limit equitable access to quality services. Participants recommended strengthening community awareness programmes, improving community clinic readiness, enhancing referral systems, and providing regular training and supportive supervision for community-based health workers. Conclusions Community-based maternal health interventions involving Community Volunteers, Community Groups, and Community Support Groups contribute to improved maternal knowledge, health-seeking behaviour, and utilization of essential maternal and newborn health services in rural Bangladesh. Sustaining these gains will require stronger primary healthcare services, continued community engagement, and targeted strategies to address persistent health system and socio-cultural barriers. These findings provide important evidence for strengthening community-based maternal and child health programmes in Bangladesh and similar resource-constrained settings.

12
Assessing Knowledge and Risk Perception of Mosquitoes and Mosquito-Borne Viruses Among Medical Students in Cyprus: A Cross-Sectional MosquitoWise Study

Dali, A. M.; Vujicic, A.; Gato, D.; Volkan, E.

2026-10-19 medical education 10.64898/2026.10.15.26365696 medRxiv
Top 4%
0.1%
Show abstract

Abstract Background: Cyprus has transitioned into a high-alert zone for mosquito-borne viruses. This necessitates a proactive assessment of its future physicians. Following the 2022 re-establishment of Aedes aegypti in Larnaca and Aedes albopictus in Limassol, Cyprus, the island is now biologically primed for local outbreaks of dengue, Zika, and chikungunya, alongside Culex-borne West Nile virus. The study assessed medical students' knowledge and risk perception. Methods: A cross-sectional online survey administered the validated MosquitoWise Health Belief Model instrument to undergraduate-entry and graduate-entry students at a university in Cyprus in mid-2026. Results: Of 1023 students, 119 responded (11.6%), with pre-clinical students overrepresented (p<0.001). Mean knowledge was 5.43/9, stronger on mosquito biology (72.5%) than virus knowledge (54.2%). Median severity was 6.00/7 against susceptibility 4.25/7. Knowledge differed by study stage (p<0.001), correlated with severity (rs = 0.399) but not susceptibility. Conclusions: The study establishes a critical baseline for pre-clinical medical students in Cyprus. Overall, participants performed better on mosquito biology when compared to mosquito-borne viruses and how they spread. Our findings highlight the value of integrating theoretical microbiology with clinical practice in medical education to enhance physicians' preparedness for the changing landscape of newly emerging infections in Cyprus and across Europe as a whole. Key Words: Arboviruses, Cross-Sectional Studies, Cyprus, Health Belief Model, Medical Students, Risk Perception.

13
Sex-, age-, and BMI-specific patterns of visual and numerical body-size ideals in Japan: a large cross-sectional web-based survey

Tabata, H.; Sakamoto, S.; Fukumura, K.; Kanda, M.; Adachi, Y.; Yoshizawa, Y.; Tamura, Y.

2026-10-19 epidemiology 10.64898/2026.10.19.26365487 medRxiv
Top 4%
0.1%
Show abstract

Background: Thinness-oriented body ideals are well described among young Japanese women, but variation in visual and numerical ideals by sex, age, and current BMI remains unclear. Methods: We analysed an unweighted web-panel sample of 27,359 Japanese adolescents and adults aged 15-69 years from the Survey of Body Shape and Health Awareness in Japanese People, a cross-sectional web-based survey. Current and ideal BMI were derived from self-reported height and weight, and visual orientation from ideal versus perceived current silhouette. Adult BMI-stratified analyses included participants aged 20-69 years. Findings: Among 27,359 participants (10,094 men and 17,265 women), relative thinness-oriented indicators increased with current BMI in both sexes. Among normal-weight women, 74.7-83.7% selected a smaller ideal silhouette and 79.2-91.2% reported an ideal BMI lower than current BMI. These indicators were also present among underweight women aged 20-29 years (44.9% and 43.4%, respectively), but declined with age. Most underweight men reported weight-gain-oriented ideals. Fine stratification showed that thinness-oriented ideals among women were common in low-normal and mid-normal BMI strata. Interpretation: Body-size ideals differed by sex, age, and current BMI. Thinness-oriented ideals among women extended beyond obesity and young adulthood, whereas underweight men generally preferred a larger body. Longitudinal and behavioural studies are needed. Funding: Cabinet Office of Japan Strategic Innovation Promotion Program (SIP), "Inclusive Community Platform" (grant no. SIPCP23C02).

14
Longitudinal Filovirus Seroreactivity Following Ad26.ZEBOV (Zabdeno) and MVA-BN-Filo (Mvabea) Vaccination in the Democratic Republic of the Congo

Wallace, H. L.; Halbrook, M. L.; Kompany, J. P.; Hoff, N. A.; Merritt, S.; Mukadi, P.; Beya, M.; Kalengi, H.; Tambu, M.; Mossoko, Z.; Kelly, J. D.; Ball, A. H.; To, A.; Wong, T.; Kavunga-Membo, H.; Hensley, L. E.; Lehrer, A. T.; Kindrachuk, J.; Mbala-Kingebeni, P.; Rimoin, A. W.

2026-10-19 infectious diseases 10.64898/2026.10.15.26365698 medRxiv
Top 4%
0.1%
Show abstract

Background: Filoviruses, specifically Ebola virus (EBOV), Bundibugyo virus (BDBV), and Marburg virus (MARV), have been the etiologic agents of multiple outbreaks of severe disease in the Democratic Republic of the Congo (DRC). Two EBOV-specific vaccine regimens have been approved for use in outbreak scenarios, including the Ad26.ZEBOV/MVA-BN-Filo (Zabdeno/Mvabea) two-dose vaccine, where the MVA-BN-Filo booster dose contains EBOV, MARV, and Sudan (SUDV) virus glycoproteins (GPs) and the nucleoprotein from Tai Forest virus. While long-term immunogenicity of up to two years has been found in clinical trial settings, limited real-world data exists. Methods: Using a multiplexed immunoassay, samples (n=698 at baseline) collected in Mbandaka, Equateur province, DRC, between September 2023 and October 2024 were assessed for seroreactivity to six filovirus antigens (1 BDBV, 2 EBOV, 2 MARV, and 1 SUDV) at three distinct periods: baseline/pre-vaccination, 6-8 weeks post-first dose (Zabdeno), at booster administration (Mvabea), and one-year post-boost dose. Results: Substantial filovirus seroreactivity was found at baseline, with 48.7% (n=340/698) of individuals being seroreactive to at least one virus antigen. High baseline seroreactivity was found against BDBV GP (31.1%, n=217/698), with lower baseline seroreactivity to EBOV GP (15.5%, n=106/698), comparatively. Overall EBOV GP seroreactivity increased to 66.8% (n=376/563) at one year-post vaccine boost and 57.6% (n=250/434) of participants were seroreactive. Despite the booster dose inclusion of SUDV GP and MARV GP, there were no substantial increases in reactivity against either antigen at subsequent timepoints. Overall filovirus seroreactivity increased at all timepoints for the entire cohort, although filovirus reactivity decreased over the study period for those who were seroreactive at baseline. Findings: These data highlight detection of significantly elevated seoreactivity to EBOV GP following first-dose administration of Ad26.ZEBOV, which remained relatively stable one-year post-booster dose administration. Additionally, this study identifies high levels of baseline seroreactivity to BDBV GP despite no previous documented outbreaks in this region of DRC. These data suggest that vaccination with the Ad26.ZEBOV-MVA-BN-Filo vaccine induces stable seroreactivity against EBOV GP, but not to other filovirus antigens.

15
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
Top 4%
0.1%
Show abstract

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.

16
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
Top 4%
0.1%
Show abstract

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 [&ge;]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.

17
Development and Validation of a Parsimonious Financial Well-Being Index in the Health and Retirement Study

Habib, M. H.; Mayeda, E. R.; Barry, L.; Arah, O. A.; Nau, C. L.; Zhou, H.; Kezios, K. L.; Nianogo, R. A.

2026-10-20 epidemiology 10.64898/2026.10.18.26365842 medRxiv
Top 5%
0.1%
Show abstract

Financial well-being (FWB) encompasses objective and subjective financial status and may influence health. We developed and validated a parsimonious FWB index using data from 23,006 Health and Retirement Study (HRS) participants aged 50 years and older from 2006 to 2022. The FWB-5 Index was derived using correlated two-factor confirmatory factor analysis accounting for household clustering. Indicators included household wealth, household income-to-poverty ratio, monthly financial strain, satisfaction with one's financial situation, and perceived financial mastery. We assessed convergent and discriminant validity using the Consumer Financial Protection Bureau Financial Well-Being (CFPB-FWB) Scale and Satisfaction with Life Scale, respectively. Associations with pre-baseline socioeconomic factors and subsequent depressive symptoms and health conditions were examined to assess construct and predictive validity. Model fit indices supported the two-factor structure (robust comparative fit index = 0.99; robust root mean square error of approximation = 0.05). Correlations were stronger with the CFPB-FWB Scale (Spearman P = 0.80) than with life satisfaction (Spearman P = 0.43). Associations with socioeconomic factors and subsequent health outcomes were in the hypothesized directions. These findings support the FWB-5 Index as a parsimonious measure for examining financial well-being and its associations with health across HRS waves, including those predating the CFPB-FWB Scale.

18
Compound climate extremes predict dengue risk at operational lead times across Brazil

Fletcher, C.; Mila, C.; Moirano, G.; Araujo, E.; Lührsen, D.; Codeco, C.; Codeco Coelho, F.; Lowe, R.

2026-10-19 public and global health 10.64898/2026.10.16.26365716 medRxiv
Top 5%
0.1%
Show abstract

Brazil has one of the highest dengue burdens globally, with transmission influenced by climate events. Yet, the effects of compound climate extremes on dengue risk and prediction have not been quantified to date. Using a Bayesian spatiotemporal model of monthly dengue cases across 435 health regions from 2010 to 2025, we estimated relative risk associated with interacting long-lag and short-lag drought indicators and temperature anomalies across nine Koppen-Geiger climatic zones, adjusting for absolute temperature and El Nino-Southern Oscillation. Long-lag dry, mid-lag warm and short-lag wet conditions were associated with the highest relative risk in five climatic zones, with temperature anomalies modifying hydrometeorological dynamics more strongly in temperate than tropical areas. Climate covariates improved the prediction of case counts and outbreaks compared to baseline models at lead times of 1, 3, 6 and 12 months, and for the upcoming season 5 months ahead. Improvements were greatest in the Northeast, Southeast, and Midwest. Recent dengue incidence provided the greatest improvement at the 1-month lead, whereas combining incidence with climate information performed best at 3- and 6-month leads. We extended our framework to weekly state-level predictions of the season ahead to align with national public health planning. We proposed a multi-staged dengue forecasting approach to enhance early warning and response across Brazil.

19
Variation in psychiatric diagnoses and use of psychotropic medication among children, adolescents, and young adults in Denmark

Sonne, H.; Kildegaard, H.; Bech, M.; Wesselhoeft, R.; Hansen, A. S. K.; Ording, A. G.; Pottegaard, A.

2026-10-20 epidemiology 10.64898/2026.10.19.26365872 medRxiv
Top 5%
0.0%
Show abstract

Background Psychiatric diagnoses and psychotropic medication use among children, adolescents, and young adults have increased in high-income countries, with concerns about geographic variation. We described national trends and geographic variation in Denmark from 2010 to 2025 and developed an interactive online tool to explore these patterns. Methods We conducted a nationwide, descriptive, repeated cross-sectional register-based study of all Danish residents aged 0-24 years in 2010-2025 (n=2,930,744), using the Danish National Patient Registry and the Danish National Prescription Registry. We estimated annual incidence, prevalence, and, for selected diagnoses, lifetime prevalence, by age and sex, and age- and sex-standardised rates across regions, health councils, and municipalities. We assessed geographic variation using deviations from national means, coefficients of variation, Gini coefficients, and funnel plots. Findings Psychiatric diagnoses and psychotropic medication use increased from 2010 to 2025. The annual prevalence of attention-deficit hyperactivity disorder (ADHD) increased from 0.41 to 2.3 per 100 individuals, autism spectrum disorders from 0.20 to 1.2, and melatonin use from 0.14 to 3.0. ADHD and autism spectrum disorders were more prevalent among boys and anxiety disorders among girls. Sertraline use was also more prevalent among girls. Geographic variation was observed across diagnoses and psychotropic medications at regional, health council, and municipal levels. For example, lifetime prevalence of autism ranged from 1.3 to 5.9 per 100 across municipalities, and in 2025 regional coefficients of variation ranged from 0.11 (sertraline) to 0.41 (atomoxetine). Results can be explored in the interactive online tool (https://bupstat.sdu.dk/?lang=en). Interpretation Psychiatric diagnoses and psychotropic medication use increased among Danish children, adolescents, and young adults, with marked geographic variation. Descriptive data cannot establish the causes of this variation, but the findings identify areas for further review and support continued monitoring. Funding Best for Us project (www.bedstforos.dk), funded by the Novo Nordisk Foundation (NNF24SA0093635) and the Obel Family Foundation (69348).

20
Change in the neutrophil-to-lymphocyte ratio after a 3-day orbital flight: A preregistered secondary analysis of NASA open data from the Inspiration4 civilian crew

GODINEZ VAZQUEZ, V. J.

2026-10-19 occupational and environmental health 10.64898/2026.10.16.26365757 medRxiv
Top 5%
0.0%
Show abstract

Background: Commercial spaceflight now carries civilians on short missions, yet their stress-axis physiology is poorly described. Earlier shuttle data suggest that sympathetic responses predominate after short flights and glucocorticoid responses after long ones. The neutrophil-to-lymphocyte ratio (NLR) is a low-cost readout of both. Methods: Preregistered secondary analysis of open clinical laboratory data (NASA Open Science Data Repository OSD-569 and OSD-575) from the four Inspiration4 crew members, each sampled seven times: three draws before launch, one the day after return (R+1) and three during recovery (R+45 to R+194). Log-transformed NLR was modelled with a linear mixed model with a random intercept per crew member and Kenward-Roger inference. Lymphocyte and eosinophil counts and C-reactive protein were secondary outcomes with false discovery rate correction. Results: All 28 draws were analysed. NLR at R+1 did not differ from pre-flight (fold change 1.04; 95% CI 0.81 to 1.34; p = 0.73); two crew members increased (+25% and +46%) and two decreased (-27% and -11%). During recovery NLR was 23% lower than pre-flight (fold change 0.77; 95% CI 0.64 to 0.92; p = 0.005). No secondary outcome changed after correction; lymphocytes were 18% lower at R+1 (95% CI -35% to +4%; q = 0.31). Between-person differences explained 58% of the variance. An ordinary regression ignoring repeated measures missed the recovery effect (p = 0.08). Conclusions: A 3-day orbital flight produced no consistent leukocyte stress signature one day after return. The lower NLR during recovery suggests that pre-flight values, not recovery values, deviate from the resting state, which has implications for how baselines are defined in short-duration spaceflight studies.