Infectious Diseases and Therapy

Importance Several influenza vaccine products are available for older adults, but evidence combining both their absolute effectiveness and head-to-head comparisons within the same large population remains scarce, limiting product-specific vaccination guidance for this high-risk group. Objective To estimate the relative and absolute effectiveness of influenza vaccines against influenza-related hospitalization and in-hospital mortality among older adults. Design, Setting, and Participants Nationwide cohort study using the French National Health Data System (SNDS), including all adults born in 1958 or earlier, living in metropolitan France, at the start of the 2023-2024 campaign. Relative effectiveness (rVE) was assessed using a landmark design with exposure fixed before epidemic onset. Absolute effectiveness (VE) was assessed using a sequential trial emulation with weekly matching of newly vaccinated individuals to yet unvaccinated controls. Follow-up ran from December 5, 2023 to April 19, 2024. Exposures Vaccination with a high-dose (Efluelda) or one of three standard-dose quadrivalent vaccines (Influvac, Fluarix, Vaxigrip), compared individually or by dosage category, and against no vaccination. Main Outcomes and Measures Hospitalization with a diagnosis of influenza and death during such hospitalization. Effectiveness was estimated as 1 minus the hazard ratio from weighted Cox models, with corresponding numbers needed to vaccinate to prevent one case. Results Among 13.8 million eligible individuals, 5.7 million (41%) were vaccinated at the beginning of follow-up. The high-dose vaccine showed greater rVE than standard-dose vaccines against hospitalization (27% [95%CI, 23 to 31%]) and in-hospital death (27% [95%CI,14 to 38%]). Absolute VE was 39% (95%CI, 38 to 41%) against hospitalization and 45% (95%CI, 40 to 49%) against in-hospital death, and was higher for the high-dose vaccine (50%) than standard-dose vaccines (36%) against hospitalization. This difference was most evident among adults 70 years and older, while overall effectiveness declined with age. Conclusions and Relevance In this study, influenza vaccination conferred moderate protection against severe outcomes in older adults, and high-dose vaccination was associated with significantly greater effectiveness than standard-dose vaccines, particularly among adults 70 years and older. These findings support product-level differentiation in vaccination strategy for this population.

Introduction: This study compared the health and economic impact of the 21-valent pneumococcal conjugate vaccine (aPCV21) vs the 20-valent pneumococcal conjugate vaccine (PCV20) on invasive pneumococcal disease (IPD) and post-meningitis sequelae (PMS) among adults aged 65 years and older in the United Kingdom (UK). Methods: A published Markov model was used to simulate a single-cohort of vaccine-naive adults who became eligible for age-based vaccination at age 65 years, with uptake occurring over time. The cohort was followed until a maximum age of 100 years. Model inputs were derived from publicly available national health data and published reports. Outcomes were discounted at 3.5% annually, and costs were adjusted to the 2024 Great Britain Pound ({pound}). Additional analyses explored the impact of changing the age-based recommendation from 65 years to 75 years. Scenarios involving instantaneous vaccine uptake rates were included as part of the sensitivity analyses. A deterministic sensitivity analysis was performed on the incremental direct medical costs between vaccinating with aPCV21 vs PCV20 under the age-based recommendation of 65 years. Results: Using an age-based recommendation of 65 years, aPCV21 led to fewer cases, deaths, and costs than PCV20. Compared with PCV20, aPCV21 averted an additional 138 IPD cases, 1 PMS case, and 22 IPD deaths, saving {pound}1.2 million in direct medical costs. Raising the age-based recommendation from 65 to 75 years and using aPCV21 (or PCV20, respectively), resulted in 120 (92) additional IPD cases, 2 (1) additional PMS case(s), 19 (14) additional IPD death(s), and an extra {pound}1.1 ({pound}0.8) million in direct medical costs. The deterministic sensitivity analysis showed that aPCV21 reduced direct medical costs across all parameter ranges. Conclusions: Compared with PCV20, aPCV21 prevented more IPD cases, IPD deaths, and direct medical costs among older adults in the UK. Changing the age-based recommendation from age 65 to 75 resulted in worse health and economic outcomes. Key words. Pneumococcal infections; pneumococcal vaccines; vaccines, conjugate; serotype; United Kingdom; health costs

Long COVID (LC) is a broad label encompassing the heterogeneous long-term consequences of SARSCoV2 infection that persist for at least 3 months post-infection. Despite its substantial global burden, there is still a lack of reliable biomarkers or panels capable of distinguishing individuals with Long COVID from healthy individuals or from those who have recovered from acute COVID-19. We previously characterized a biomarker panel comparing 85 adults with WHO-defined Long COVID against 85 age- and sex-matched controls who had recovered within three months of acute COVID-19 in 2020, at between 12 and 24 months post-infection. That initial profile evaluated blood cell counts, coagulation status, routine SARS-CoV-2 serology, immune cell populations, and basic cytokine levels based on Luminex assays. We have enhanced our biomarker panel by incorporating more precise cytokine quantification using the high-precision ELLA automated immunoassay system. To assess potential ongoing peripheral systemic inflammation, we measured classical inflammatory markers in blood, including C-reactive protein (CRP), tumor necrosis factor alpha (TNFalpha), interleukin (IL)1beta, and IL6. In this manuscript, we present data that confirm age- and gender-matching between the LC and control group; and compared differences in cytokine levels and comorbidities.

Objective: This study estimated the vaccine effectiveness (VE) of 20-valent pneumococcal conjugate vaccine (PCV20) against culture-confirmed pneumococcal pneumonia hospitalizations among adults using a test-negative case-control design. Methods: We included adults ([≥]18 years) hospitalized with pneumonia in the U.S. Veterans Affairs Healthcare System between January 2023 and December 2025 who had respiratory cultures collected. VE was estimated using multivariable logistic regression adjusted for demographic and clinical characteristics. Subgroup analyses were conducted by age, risk group, and U.S. census region. Sensitivity analyses included inverse probability of treatment weighting (IPTW) and evaluation allowing previous PCV13 vaccination. Results: Among 34,009 pneumonia hospitalizations, 837 (2.5%) were Streptococcus pneumoniae culture-positive and 7,428 (21.8%) individuals had received PCV20. PCV20 vaccination was associated with lower odds of culture-confirmed pneumococcal pneumonia hospitalization among adults aged [≥]65 years (VE 20.4%; 95% CI: 2.1%, 35.3%), with greater effectiveness observed among those with chronic medical conditions (VE 24.4%; 95% CI: 0.7%, 42.4%). VE was highest in the Western region among adults aged [≥]65 years (39.6%; 95% CI: 3.2%, 62.3%), a region with a high burden of serotype 4 disease. Overall, VE among adults aged [≥]18 years was 8.8% (95% CI: -8.8%, 23.6%). Findings were consistent across multivariable and IPTW-adjusted analyses. Conclusion: PCV20 provided significant protection against pneumococcal pneumonia hospitalizations among older adults, with greater effectiveness in regions where vaccine-covered serotypes are more prevalent. These findings support the importance of aligning pneumococcal vaccination strategies with regional serotype distribution to maximize vaccine impact.

Objective: Treatment of acute COVID-19 with anti-viral and immunomodulator medications demonstrates a reduced risk of long-term outcomes. To date, remdesivir, an intravenous (IV) antiviral that prevents RNA transcription, has not been evaluated in people with Long COVID (LC). This study assessed the feasibility of a five-day IV remdesivir intervention for individuals with LC. Methods: Seventy-three participants aged [≥]18 years with a confirmed LC diagnosis were recruited across two sites in the United Kingdom to receive a five-day course of IV remdesivir. Primary feasibility outcomes included recruitment, treatment completion, acceptability, and safety. Exploratory patient-reported (e.g. Fatigue Assessment Scale [FAS]) and clinical outcomes (e.g. 6-minute walk test [6MWT]) were also collected. Results: Of 106 individuals screened, 73 were enrolled and 71 (97%) completed the 5-day IV remdesivir regimen. Follow-up assessments were completed by 70 participants (96%), with high completion rates observed across clinical assessments, patient-reported outcomes and symptom tracking. No severe adverse reactions were reported. Improvements were also observed in several exploratory patient-reported and clinical outcomes. Conclusion: We demonstrated the feasibility and acceptability of administering IV remdesivir in people with LC. Analysis of secondary outcomes suggests therapeutic promise, but rigorous evaluation in large-scale randomised controlled trials is essential to determine the true efficacy and clinical utility of intravenous remdesivir in this population.

Seasonal influenza remains a major cause of morbidity and mortality worldwide. Although neuraminidase inhibitors improve outcomes, influenza-related deaths persist. We evaluated the impact of early aspirin (ASA) and non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use on outcomes in adults hospitalized with influenza. This retrospective study included adults admitted to the University of Minnesota Medical Center from 2016 to 2018. Continuous variables were summarized as medians with interquartile ranges (IQRs) and categorical variables as counts and percentages. Group comparisons used Wilcoxon rank-sum, Chi-square, or Fishers exact tests. Analyses included case-control comparisons, assessments by vaccination status, and subgroup analyses by early ASA or NSAID use. Among 2,816 patients, 320 had laboratory-confirmed influenza, with vaccination less common among cases. Unvaccinated patients had higher rates of intensive care unit (ICU) admission (23.6% vs. 11.1%; P = 0.003) and ventilatory support (15.0% vs. 6.1%; P = 0.009). In vaccinated patients, early ASA use was associated with older age and higher in-hospital mortality, whereas early NSAID use was associated with no in-hospital deaths, better one- and three-year survival (P < 0.001), and fewer, though not statistically significant, cardiovascular complications. In unvaccinated patients, ASA use was associated with lower three-year survival (59.1% vs. 79.2%; P = 0.013), while NSAID use was associated with fewer ICU admissions and no cardiovascular or renal complications. In both vaccinated and unvaccinated adults hospitalized with influenza, early NSAID use was associated with improved survival and fewer complications, whereas ASA use was associated with worse outcomes.

Purpose: To compare the efficacy and safety of intravenous cefazolin versus antistaphylococcal penicillins for the treatment of MSSA bacteremia in adults using evidence exclusively from randomized controlled trials. Methods: We searched 5 databases for RCTs comparing definitive intravenous cefazolin with ASPs (oxacillin, cloxacillin, flucloxacillin, nafcillin) in adults with MSSA bacteremia. Primary outcomes were 90-day all-cause mortality and acute kidney injury (AKI). Secondary outcomes included adverse event-related treatment discontinuation and persistent bacteremia (>72h). Dichotomous outcomes were synthesized as risk ratios (RRs) with 95% confidence intervals (CIs) using random-effects models with Paule-Mandel estimation and Hartung-Knapp-Sidik-Jonkman inference. Fixed-effect Mantel-Haenszel models were performed as sensitivity analyses. Results: Two RCTs randomized 1,656 participants (SNAP, n = 1,341; CloCeBa, n = 315), of whom 1,579 contributed to the 90-day mortality analysis. There was no statistically significant difference in 90-day mortality (RR 0.90, 95% CI 0.57-1.41; I2 = 0%). Both trials favoured cefazolin for acute kidney injury, but the random-effects estimate was highly imprecise (RR 0.26, 95% CI 0.00-939,970.59; I2 = 81.7%). Treatment discontinuation also favoured cefazolin directionally, although the random-effects estimate was imprecise (RR 0.24, 95% CI 0.00-24.41; I2 = 36.2%). Microbiological outcomes were synthesized narratively because definitions and assessment time points differed between trials. Conclusion: Randomized evidence supports cefazolin as a potential definitive treatment option when adequate source control, appropriate antimicrobial dosing, and clinical monitoring can be achieved. However, the limited number of trials and imprecision in pooled estimates warrant cautious interpretation.

Objectives: To evaluate the epidemiological evolution of unique pneumococcal serotypes covered by either PCV20 or PCV21, common serotypes by both vaccines and non-vaccine serotypes in adults. Methods: We characterized all national IPD clinical isolates from January 2009 to June 2026. Results: The highest burden of IPD was caused by serotypes shared between PCV20 and PCV21 with serotypes 3 and 8 the most prevalent in adults of all ages. During the pre-pandemic period, IPD caused by unique-PCV20 serotypes declined probably due to herd protection by paediatric vaccination with PCVs. In contrast, unique-PCV21 serotypes increased in incidence accounting for more cases than unique-PCV20 serotypes. However, after the COVID-19 pandemic, a different pattern was observed with unique-PCV20 serotypes increasing in incidence due a marked rise in IPD caused by serotypes 4 and 14 that has progressively reduced the gap in disease coverage. In adults aged 18-64 years, the fraction of disease that could be prevented with PCV20/PCV21 changed from 5% in favour of PCV21 (years 2022/2023) to 15% in favour of PCV20 (year 2026) whereas in adults [&ge;]65 years the vaccine contribution declined from 20% in favour of PCV21 (year 2022) to 8% in 2026. Conclusions: IPD trends in adults have changed after the COVID-19 pandemic, especially in recent years. Our study emphasizes the rapid re-emergence of infections caused by traditional PCV7 serotypes especially serotypes 4 and 14 and reinforce the idea that the use of broader PCVs must be accompanied by an increase in the uptake rates in adults of all ages.

Importance: OPAT is an underutilized strategy in low- and middle-income countries (LMICs). Addressing the knowledge gaps among frontline physicians through structured interventions is vital for optimizing hospital bed utilization and antimicrobial stewardship. Objective: To assess whether a structured multidisciplinary care bundle is associated with improved patient enrollment and clinical care quality in an OPAT program in India. Design, Setting, and Participants: This pre-post quality improvement study was conducted in the Department of General Medicine at a tertiary care referral hospital in Rishikesh, India. Data from patient encounters during a 6-month pre-intervention period (December 1, 2023 to May 31, 2024) were compared with encounters during a 6-month post-implementation period (January 1, 2025 to June 31, 2025). Participants included all postgraduate residents serving as frontline clinical practitioners. Interventions: A structured OPAT bundle comprising a formalized educational curriculum (interactive didactic sessions and bedside practical training), standardized eligibility screening, and a coordinated telephonic monitoring protocol (from June 1, 2024 to December 31, 2024). Main Outcomes and Measures: The primary outcome was the change in the number of eligible patients enrolled in OPAT. Secondary outcomes included clinical process quality indicators (counseling, IV access arrangement, and monitoring compliance), 30-day rehospitalization rates, and therapy-related complications. Results: A total of 20 preintervention patient encounters were compared with 39 postintervention encounters, with similar baseline characteristics between groups (mean age, 37 vs 40 years; male gender, 65% vs 69.2%). Prior to implementation, only 33.3% (20 of 60) of eligible patients received OPAT, whereas 100% (39 of 39) of eligible patients were enrolled following the intervention (p < 0.001). Key clinical processes reached 100% compliance post implementation, including patient counseling (40% vs 100%; p < 0.001), pre-discharge IV access (40% vs 100%; p < 0.001), and daily telephonic monitoring (10% vs 100%; p < 0.001). Safety outcomes remained stable, with no significant differences in readmission rates (5.0% vs 0%; p = 0.34) or drug-related complications. Conclusions and Relevance: This quality improvement study provides evidence that a structured package of OPAT bundle interventions is associated with a transition to universal enrollment of eligible patients and perfect adherence to safety indicators. These results suggest that standardizing the outpatient transition through physician education and coordinated monitoring is a feasible and effective strategy for optimizing hospital resource utilization in LMICs.

Background Otitis media is a leading cause of childhood morbidity and presents a significant healthcare burden worldwide. Streptococcus pneumoniae is a major aetiological agent of OM, and the introduction of pneumococcal conjugate vaccines into the Malaysian National Immunisation Programme in 2020 would have altered pneumococcal carriage and serotype distribution. This study aimed to determine pneumococcal carriage, serotype distribution, and associated risk factors among children with OM in the early post-PCV era in Peninsular Malaysia. Methods and Findings A total of 360 children with OM were recruited from hospitals on the east and west coasts of Peninsular Malaysia between 2023 and 2025. Nasopharyngeal and middle ear fluid samples were collected for Spn isolation by culture, followed by serotyping using multiplex PCR. Sociodemographic, environmental, and medical history data were analysed for associations with pneumococcal carriage using chi-square, Fishers exact tests, and logistic regression. Pneumococcal carriage was detected in 26.7% of children in either NP or MEF samples, with carriage rates of 25.6% and 1.9% in NP and MEF samples, respectively. The most prevalent serotypes were 23A, 15B/15C, non-typable strains, 19F, and 11A/11D. Daycare attendance (p = 0.012, aOR [95% CI]: 2.177 [1.186 - 3.995] and residence in rural areas (p = 0.019, aOR [95% CI]: 2.476 [1.159 - 5.292] were significantly associated with pneumococcal carriage. The main limitation of the study was the reliance on self-reported questionnaire data, which may have introduced recall bias and reporting errors. Conclusions The predominance of non-vaccine serotypes and non-typable Spn indicates ongoing serotype replacement and the emergence of phase-variant strains in the early post-PCV era. Continued surveillance is essential to monitor these changes and inform the development of next-generation pneumococcal vaccines. This study was registered under clinical trial registration number NCT05429541.

Objectives: Capturing adequate blood volume for blood cultures is critical for accurate detection of bloodstream infections. Pediatric volume targets vary by age and weight, whereas adult targets are standardized. The BD BACTEC FXI Culture System (FXI) contains an integrated calibrated load cell capable of automatically reporting blood volume measurements for each vial loaded onto the system. This study evaluated the accuracy of the FXI's blood volume measurements in simulated pediatric and adult patients. Methods: Mock pediatric and adult blood draws were performed, using bagged whole blood, to replicate real-world collection protocols. Syringe-collected blood volumes ranged from 2.0 to 15.0 mL for pediatric patients, depending on mock patient weight, and were fixed at 40.0 mL for adults. Samples were inoculated into BD BACTEC Peds Plus/F, Plus Aerobic/F, and Lytic/10 Anaerobic/F Culture Vials, with a target volume of 2.0 to 10.0 mL per bottle. Reference blood volumes were determined gravimetrically using manually obtained pre- and post-inoculation weights with a blood-specific gravity of 1.055 g/mL and were compared to the automatically measured, gravimetric-based blood volumes reported by the BACTEC FXI Culture System. Results: Automated volume estimates were accurate to a mean error of -0.03 mL per bottle (SD, 0.40 mL; n=168; 95% CI, -0.09 mL, 0.03 mL) and -0.08 mL (SD, 0.79 mL; n=72; 95% CI, -0.26 mL, 0.10 mL) when assessing total volume collected per patient. Conclusions: Our findings demonstrate that the automated system can quantify blood volumes in BACTEC culture vials and support blood volume monitoring for pediatric and adult collections. The gravimetric approach is also amenable to full automation for efficient and accurate blood volume determination.

BACKGROUND: Conventional bronchoalveolar lavage (BAL) culture has limited sensitivity in lung transplant recipients due to universal antimicrobial prophylaxis and inability to detect non-culturable organisms. Metagenomic sequencing of BAL offers culture-independent pathogen identification, but concordance with conventional culture and clinical utility in the immediate post-transplant period have not been evaluated. METHODS: We prospectively enrolled 19 adult lung transplant recipients undergoing serial bronchoscopies during the immediate post-transplant period. BAL samples (n=33) were tested in parallel with conventional culture, microbial cell-free DNA (mcfDNA) sequencing (Karius Focus BAL; with quantitation determined by research analysis), and Oxford Nanopore sequencing using a unified three-tier organism classification framework. BAL host-response biomarkers were profiled concurrently. RESULTS: Karius reported Tier 1 pathogens in 19/33 episodes (58%) versus 8/33 by conventional culture (24%); organism-level concordance was low (Cohen's kappa 0.18). In 16 episodes where Karius reported a pathogen not recovered by culture, 8 across 3 participants represented predictive reports, defined as the same organism subsequently confirmed as causing invasive infection 2-46 days later, including fatal Pseudomonas pneumonia, Enterococcal surgical site infection, and Candidemia. Nanopore sequencing had low yield due to contaminating human DNA. Quantitative mcfDNA burden correlated positively with multiple alveolar inflammatory biomarkers including total protein, IL-6, and sST2. INTERPRETATION: BAL mcfDNA metagenomics identified clinically relevant pathogens not recovered by conventional culture, including predictive reports and non-culturable organisms. Quantitative mcfDNA signal correlated with alveolar inflammatory mediators, supporting the biological relevance of mcfDNA detection beyond conventional diagnostic classification and a role for metagenomic surveillance in the early post-transplant period.

Rationale. Guidelines disagree on antibacterial treatment for adults with community-acquired pneumonia and a positive respiratory viral test, particularly hospitalized patients and outpatients with comorbidities. Objectives. To estimate associations between antibacterial treatment selected for community-acquired pneumonia and outcomes in adults with virus-positive, imaging-evaluated nonsevere pneumonia. Methods. We conducted a retrospective multicenter study using Epic Cosmos data from 2016-2025. Hospitalized patients treated empirically by 24 hours were compared by continuation during hours 24-48; outpatients were compared by prescription at emergency-department discharge. Analyses were stratified by guideline-defined comorbidity and used propensity-score overlap weighting with source-cluster bootstrap confidence intervals. Exploratory analyses assessed respiratory virus, antiviral treatment, antibacterial class, and outpatient timing. Measurements and Main Results. The cohort included 376,320 adults: 275,604 inpatients and 100,716 outpatients. Inpatients who continued treatment had higher 30-day adverse-event risk without guideline comorbidity (adjusted risk difference, 1.70 percentage points; 95% confidence interval, 0.80-2.39) and with guideline comorbidity (2.56; 1.88-3.14), and longer post-landmark stay (adjusted mean ratios, 1.14 and 1.08). Exploratory class-specific analyses showed the largest adverse-event and mortality associations with broad therapy targeting resistant staphylococci or Pseudomonas; macrolide-containing and other atypical coverage showed no consistent adverse signal. Outpatient prescribing was associated with lower risks, but care-transition and residual confounding remained. Conclusions. Continued inpatient therapy after the empiric period showed no evidence of benefit and was associated with worse observed outcomes. Outpatient associations favored prescribing but remained vulnerable to care-transition and residual confounding.

Sickle cell disease (SCD) is a significant contributor to the global disease burden, particularly in developing countries where access to care is limited, and coordinated multidisciplinary care is often unavailable. Hydroxyurea is the only readily available disease-modifying-drug therapy in many resource-limited settings, such as Jamaica where it is subsidized through the National Health Fund (NHF). This cross-sectional study assessed barriers to healthcare access and hydroxyurea use in Jamaica among adults with SCD and parents or caregivers of children with SCD from four regional health authorities and a specialized SCD centre. Participants completed an interviewer-assisted questionnaire collecting information on sociodemographics, healthcare access, hydroxyurea utilization and associated barriers. All analyses were exploratory. The study recruited 173 adults (mean age 34.0{+/-}11.4 years, 73.6% female, 48.6% urban, 75.1% with secondary education) and 189 parents/caregivers (mean age of parents/caregivers 37.2{+/-}10.2 years and children 7.1{+/-}4.8 years, 55.0% of children female, 50.3% urban, and 64.3% of parents/caregivers with secondary education). Overall, emergency care was most commonly accessed at public hospitals (87.3%), with the SCU (21.5%) and private hospitals (7.7%) less commonly reported. Routine care was accessed at the SCU by 85.9%, with 28.6% also attending hospital outpatient clinics. Enrolment in the National Health Fund (NHF) drug subsidy programme was reported by 50.9% of adults and 36.0% parents/caregivers, while insurance coverage was reported by 34.7% and 31.8%, respectively. Common healthcare access barriers included not being seen quickly enough when in pain (77.8% adults), worry or fear (47.2% overall), long wait times (39.2% overall), frustration or anger (29.3% overall), and high transportation costs (22.4% overall). Hydroxyurea awareness was reported by 62.4% adults and 67.6% parents/caregivers, while 45.0% and 55.0% reported receiving hydroxyurea education, respectively. Awareness and education were both higher among adult females and parents/caregivers of older children, while awareness was also greater among tertiary-educated adults. Overall, 30.2% of adults and 39.4% of children reported initiating hydroxyurea (p=0.18). Among patients advised to take hydroxyurea, 68.4% adults and 77.1% children initiated (p=0.18), and 50.0% adults and 73.4% children (p=0.001) were currently using it. Among adults, lower initiation was associated with reporting insufficient knowledge about hydroxyurea (odds ratio, OR=0.1), disinterest in another medication (OR=0.1), and having neither NHF coverage nor other health insurance (OR=0.1). Among parents/caregivers, initiation and current use were lower among those who were disinterested in another medication (OR=0.1 and 0.02, respectively) and concerned about side effects (both OR=0.2). Poor adherence was most commonly attributed to forgetting to take the medication. Adherence was lower among adults who reported inadequate social support and healthcare being too expensive, including co-pay. Among children, adherence was greater among females, younger children and those with tertiary-educated parents. Findings suggest hydroxyurea awareness and education are inadequate, and initiation and continued use remain suboptimal, highlighting the need for improved education strategies and NHF enrolment. Strategies should be tailored to better engage males, parents and patients of different age groups, and those with lower educational attainment. Greater support is needed to address mental health and transportation challenges, alongside protocols aimed at reducing wait times.

Background: Reactivation of herpes simplex viruses (HSV) can occur in the early post-allogeneic hematopoietic cell transplant (aHCT) period despite antiviral prophylaxis. Few studies have assessed HSV infection in the modern era, in which acyclovir/valacyclovir is recommended for up to 1 year post aHCT. We evaluated the incidence and management of breakthrough HSV during the first 100 days post-aHCT over two decades. Methods: Patients who received their first aHCT at Fred Hutchinson Cancer Center between 2002-2022 were reviewed for breakthrough HSV infection within the first 100 days on prophylaxis (acyclovir 800 mg or valacyclovir 500 mg twice daily). Cases were identified via culture, polymerase chain reaction, and/or direct fluorescent antibody testing; clinical records were reviewed for symptoms, outcomes, and prophylaxis/treatment regimens. Refractory/resistant (R/R) infections were defined according to consensus guidelines. Results: We reviewed data from 4,357 aHCT recipients aged [&ge;]18 years, among whom 3,749 (86%) were HSV seropositive and 23 developed breakthrough HSV infection (observed probability = 0.6%). Among those who had an infection, the median time from transplant to first positive test was 46 days (IQR: 24.0-69.5). Oral and genital mucosa were the most common sites of infection. In total, 11 of 23 (47.8%) patients with breakthrough HSV developed R/R infection. Conclusions: Breakthrough HSV infections are rare in the first 100 days after aHCT among patients receiving antiviral prophylaxis. Refractory/resistant infections were uncommon but represented almost half of breakthrough cases. Our findings highlight the sustained effectiveness of universal prophylaxis in the early post-transplant period.

Background and Objectives: Preterm infants are commonly transfused, yet direct cardiorespiratory effects of red blood cell (RBC) transfusions remain poorly understood. We explored the feasibility of using multicentre electronic health data (EHD) to study such cardiorespiratory responses. Methods: Highly granular routine EHD were collected from preterm infants born <32 weeks gestational age at three European centres. Heart rate, oxygen saturation, and respiratory rate were evaluated 12 hours before and after the RBC transfusion. Results: A total of 321 transfusions in 164 infants were analysed. Overall, there was no significant change in the rate of bradycardia and apnoea following transfusion. Cardiorespiratory parameters varied substantially between infants; e.g. 20% of transfusions were associated with an unexpected, significant increase in heart rate. Respiratory rate and oxygen saturation exhibited similarly heterogenous patterns following transfusion. In sub-group analysis, the proportion of transfusions with increased heart rate was significantly higher within the first two weeks than later (32% vs 13%, p=0.0019). Conclusions: Multicentre EHD extraction allows to identify otherwise masked short-term effects of RBC transfusions on cardiorespiratory parameters, possibly indicating cardiac or pulmonary overload. Such effects may vary with adaptation to anaemia. Analysing EHD may ultimately enable personalized transfusion practice.

Neutralizing antibodies are a correlate of protection (CoP) of SARS-CoV-2 vaccine efficacy. However, data informing CoPs often explicitly exclude people on immunosuppressive therapies who are at an increased risk of symptomatic and severe COVID-19, delayed viral clearance, and death. Investigating the relationship between antibodies and protection for people on immunosuppressive therapies could provide insights into mechanisms of protection. We performed a systematic search to identify studies reporting SARS-CoV-2 binding antibody levels after mRNA vaccination in people with hematological malignancies, neurological disorders, rheumatic diseases, and mixed immune-mediated inflammatory disorders (IMIDs) on immunosuppressive therapies including B-cell depletion, JAK inhibitors, and S1P inhibitors, as well as healthy controls. Binding antibody levels varied between cohorts receiving different immunosuppressive treatments. Compared to healthy controls the lowest antibody levels were observed in subjects treated with B-cell depletion (54.5-fold reduction, 95% CI: 34.5-86.2) and S1P inhibitors (24.8-fold reduction, 95% CI: 13.2-46.7). To assess the association between antibody level and protection, we used data from a previous study of COVID-19 vaccine effectiveness in people with the same underlying conditions. We linked vaccine effectiveness estimates with the predicted antibody level in people on immunosuppressive therapies (using antibody data including this meta-analysis of binding antibody levels). Predicted neutralizing antibody levels were correlated with vaccine effectiveness both for infection and hospitalization (p<0.0001 and p<0.0001, respectively). However, we found that for any given antibody level, people who are immunosuppressed had lower protection against infection and hospitalization than a healthy population.

Background: Host response and biomarker research to advance sepsis therapeutics requires well-characterized cohorts with longitudinal biospecimens across a range of hosts and infections. Automated screening based on SIRS criteria is sensitive but nonspecific and identifies more candidates than research teams can approach, sample, and follow longitudinally. We evaluated a structured enrichment review by non-physician study staff, done after automated screening in a hospital-wide prospective sepsis cohort. Methods: The CISID cohort is a prospective observational study of hospitalized patients with suspected sepsis, enrolling adults from the ED, inpatient wards, and ICUs at a tertiary academic medical center. Patients were identified through: (1) automated electronic health record screening for two or more SIRS criteria with a 24-hour lookback, documentation of microbiologic culture or PCR, and receipt of a new antibiotic; (2) a sepsis enrichment step of structured chart review by trained non-physician study staff; and (3) discussion with the primary clinical team. Enrolled patients underwent physician adjudication into four diagnostic categories. To evaluate the enrichment step, we analyzed all patients screened during a 9-week period, assigned a composite "sepsis-likely" variable (CDC Adult Sepsis Event criteria or ICD-10 code R65.20/R65.21 within 48 hours before or after screening), and assessed mortality across each stage of screening. We also assessed concordance of the composite with physician adjudication among enrolled patients. Results: From November 2023 through February 2026, 4,318 patients screened in through EHR-based automated screening; 1,220 (28%) were flagged for enrollment, and 288 were enrolled. Physician adjudication classified 209 (73%) as sepsis, 46 (16%) as infection without sepsis, 14 (5%) were classified as undifferentiated critical illness, and 19 (6.6%) as non-infectious sepsis mimics. Patients with sepsis were severely ill (median SOFA score, 9; ICU admission, 80%; shock, 48%), and 51% were immunocompromised; mortality was 14% in hospital and 27% at 90 days. In a 9-week sample of 907 screened encounters, 21% of those deferred and 70% of those flagged for enrollment met the sepsis-likely composite, a 3.3-fold increase in prevalence after structured study team review. Conclusions: A brief structured enrichment review after automated screening tripled the prevalence of EHR-based sepsis indicators among patients selected for enrollment, while concentrating enrollment efforts on roughly one-quarter of screened-in patients in this hospital-wide, all-source suspected-sepsis cohort. This approach may help prospective cohorts direct limited biospecimen resources toward patients most informative for host-response and biomarker research.

Objectives To evaluate the impact of COVID-19 vaccination on the prevention of long COVID (LC) in the Omicron era through an updated systematic review and meta-analysis. Methods We performed an update of our previously published systematic review and meta-analysis of vaccination and LC risk (searches between 1 January 2022 and 1 March 2024). Databases (Embase, MEDLINE, PubMed, Europe PMC, LILACS, Cochrane COVID-19 Study Register) were searched for studies published between 1 March 2024 and 13 July 2026. Observational studies assessing the impact of vaccination on the risk of LC four or more weeks after SARS-CoV-2 infection were included. Vaccines were restricted to those centrally authorised in the European Union. Random-effects meta-analyses, restricted to adults, were performed to calculate pooled odds ratios (OR) of LC in three comparisons: vaccinated (any dose) versus unvaccinated; booster vaccination versus unvaccinated; and booster vaccination versus primary course vaccination only. Results Nineteen new studies were identified, of which ten were included in the updated meta-analyses alongside eight studies from the original review. The pooled OR of LC in vaccinated adults (any dose) versus unvaccinated was 0.75 (95% confidence interval [CI] 0.67-0.84; 13 studies). ORs were also lower for booster vaccination versus unvaccinated (0.73; 95% CI 0.65-0.82; 6 studies), and booster vaccination versus primary course vaccination (0.63; 95% CI 0.53-0.75; 6 studies). Significant associations between vaccination and lower LC odds were observed in subgroup analyses of mRNA-only vaccination and LC outcomes three or more months after infection. Conclusions This updated review and meta-analysis reinforces our previous finding that vaccination may reduce the burden of LC in the Omicron era, with booster doses potentially providing additional protection. Although evidence in high-risk groups now prioritised for vaccination in most countries remains limited, these findings clearly demonstrate the benefits of vaccination and support current seasonal vaccination strategies.

ObjectivesRespiratory Syncytial Virus (RSV) vaccine policies have varied globally since their approval in 2023. In the UK, policy has adapted in line with National evidence generation such that from Autumn 2026 at-risk persons [&ge;]65 years old will become eligible for vaccination. Immunosuppressed persons <65 years will still not be offered protection. The objective of this study is to investigate the relative burden of RSV infection by age and immunosuppressed status (IC). DesignRetrospective observational cohort study using routine healthcare data from North West London Integrated Care System. ParticipantsPatients with a confirmed diagnosis of a respiratory viral infection (RSV, Influenza A and B, SARS-CoV2) between October 2021 and July 2025. Main outcomes measuresPrevalence and severity of RSV infection in immunosuppressed persons <65 years old, and to provide a comparative analysis with Influenza and SARS-CoV2 in a sub-cohort tested using a 4-in-1 combined rapid PCR test. ResultsDuring the study period, 1226 patients were diagnosed with RSV of whom 596 (48.6%) were <65 years old. In 1091 patients with clinical data, 341 (31.3%) were IC. Fifty (9.9%) patients <65 years old had severe infection (ICU admission or death within 28 days of diagnosis), of whom 14 (28.0%) were IC. Proportionally, 16.7% of all RSV-associated deaths and 55.1% of all ICU RSV-admissions occurred in adult patients <65 years old. RSV accounted for 665 (10.1%) infections confirmed by 4-in-1 viral PCR testing. Eight-nine (13.4%), 172 (9.3%) and 448 (12.0%) patients with RSV, Influenza A and SARS-COV2 experienced severe infection, of whom 32 (36.0%), 82 (47.7%) and 156 (34.8%) were <65 years old respectively. Eight (25.0%), 20 (24.4%) and 52 (33.3%) of patients <65 years old with severe infection were IC. On adjusted analysis, having an immunosuppressive condition increased the odds of a severe SARS-CoV2 infection, OR (95% CI) 1.36 (1.08-1.71) but not a severe RSV or Influenza infection. ConclusionsSevere RSV infections occur in persons <65 years old, with a significant proportion of patients having an immunosuppressive condition. Urgent research is needed to investigate the potential benefit of extending the current UK RSV vaccine policy to protect younger immunosuppressed adults.