Consensus Statement: Technical Standards for Thoracoabdominal Normothermic Regional Perfusion.

BACKGROUND: Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a powerful technique for optimizing organ procurement from donation after circulatory death donors. Despite its rapid adoption, standardized guidelines for TA-NRP implementation are lacking, prompting the need for consensus recommendations to ensure safe and effective utilization of this technique. METHODS: A working group composed of members from The American Society of Transplant Surgeons, The International Society of Heart and Lung Transplantation, The Society of Thoracic Surgeons, and The American Association for Thoracic Surgery was convened to develop technical guidelines for TA-NRP. The group systematically reviewed existing literature, consensus statements, and expert opinions to identify key areas requiring standardization, including predonation evaluation, intraoperative management, postdonation procedures, and future research directions. RESULTS: The working group formulated recommendations encompassing donor evaluation and selection criteria, premortem testing and therapeutic interventions, communication protocols, and procedural guidelines for TA-NRP implementation. These recommendations aim to facilitate coordination among transplant teams, minimize variability in practice, and promote transparency and accountability throughout the TA-NRP process. CONCLUSIONS: The consensus guidelines presented herein serve as a comprehensive framework for the successful and ethical implementation of TA-NRP programs in organ procurement from donation after circulatory death donors. By providing standardized recommendations and addressing areas of uncertainty, these guidelines aim to enhance the quality, safety, and efficiency of TA-NRP procedures, ultimately contributing to improved outcomes for transplant recipients.

Non-muscle myosin 2 can incorporate into established filaments in cells without an assembly competence domain.

Myosin 2 dynamically assembles into filaments that exert force on the actin cytoskeleton. To form filaments, myosin 2 monomers transition between folded and unfolded states. Monomer unfolding exposes an extended coiled-coil that interacts with other monomers in parallel and antiparallel fashions, enabling bipolar filament formation. A C-terminal domain of the coiled-coil, termed assembly competence domain (ACD), has been repeatedly identified as necessary for filament assembly. Here, we revisit ACD contribution when full-length filaments are present. Non-muscle myosin 2A lacking the ACD (ΔACD) initially appears diffuse, but triton extraction of cytosolic fraction reveals cytoskeletal association. Disruption of the folded monomer enhances the cytoskeletal fraction, while inhibition of endogenous filament assembly appears to reduce it. Finally, high resolution imaging of endogenous and exogenous bipolar filamentous structures reveals highly coincident signal, suggesting ΔACD constructs co-assemble with endogenous myosin 2A filaments. Our data demonstrate that while the ACD is required for de novo filament assembly, it is not required for monomers to recognize and associate with established filaments in cells. More broadly, this highlights the existence of distinct mechanisms governing myosin 2 monomer assembly into nascent filaments, and monomer recognition and association with established filaments to maintain steady-state contractile networks.

Natural malaria infection elicits rare but potent neutralizing antibodies to the blood-stage antigen RH5.

Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is the most advanced blood-stage malaria vaccine candidate and is being evaluated for efficacy in endemic regions, emphasizing the need to study the underlying antibody response to RH5 during natural infection, which could augment or counteract responses to vaccination. Here, we found that RH5-reactive B cells were rare, and circulating immunoglobulin G (IgG) responses to RH5 were short-lived in malaria-exposed Malian individuals, despite repeated infections over multiple years. RH5-specific monoclonal antibodies isolated from eight malaria-exposed individuals mostly targeted non-neutralizing epitopes, in contrast to antibodies isolated from five RH5-vaccinated, malaria-naive UK individuals. However, MAD8-151 and MAD8-502, isolated from two malaria-exposed Malian individuals, were among the most potent neutralizers out of 186 antibodies from both cohorts and targeted the same epitopes as the most potent vaccine-induced antibodies. These results suggest that natural malaria infection may boost RH5-vaccine-induced responses and provide a clear strategy for the development of next-generation RH5 vaccines.

Sex Related Differences in Perioperative Outcomes after Complex Endovascular Aneurysm Repair.

OBJECTIVE: Prior studies suggest female sex is associated with worse outcomes after complex endovascular aneurysm repair (EVAR) due to anatomic differences. Therefore, we aimed to compare 30-day perioperative and long-term outcomes after complex EVAR by sex METHODS: A single-center retrospective review of consecutive elective and emergent complex EVAR with company-manufactured devices, laser fenestration, snorkel/periscope, or octopus technique was performed from 2012-2023. The primary outcome was a composite endpoint of any major adverse event (MAE), new-onset dialysis, or death within 30 days. Secondary 30-day technical and long-term outcomes were also assessed RESULTS: 293 patients (57 females, 19%), mean age 74 years, underwent complex EVAR with commercially available ZFEN (71%), p-Branch (2%), laser fenestration (8%), snorkel/periscope (16%), or octopus (2%) techniques. Females had significantly different aneurysm-related anatomic characteristics compared to males, including smaller aneurysm diameters (58 ± 7.2 vs 64 ± 13.2 mm, P<.001), more involved aneurysm extent (21.7% vs 9.8% thoracoabdominal, P=.04), increased renal artery calcification (43.9% vs 27.1%, P=.01), and smaller iliac (7.6 ± 1.3 vs 8.9 ± 1.8 mm, P<.01). Operative outcomes were similar; however, females had a greater need for adjunctive access conduits (21.1% vs 10.6%, P=.04), lower technical success (91.2% vs 98.3%, P=.02), and longer median [interquartile range] length of stay (3.0 [4.0] vs 2.0 [2.5] days, P<.001). The composite 30-day outcome of any MAE, new dialysis, or death was not significantly different (15.8% females vs 11.4% males, P=.37). Technical endpoints including 30-day rates of target artery occlusion and type 1 or 3 endoleak were also similar between groups. At mean follow-up of nearly 3 years, females had significantly lower rate of renal function decline (16.0% vs 41.9%, P<.001), but no differences were found in long-term all-cause mortality, aneurysm sac regression, reintervention, or total follow-up imaging studies between groups. CONCLUSIONS: Females undergoing complex EVAR had challenging anatomy with higher intraoperative target artery occlusion, conduit use, and longer length of stay. However, 30-day and long-term outcomes were similar, suggesting females can undergo complex EVAR with high technical success and comparable perioperative outcomes to males. Females appeared to have protection from long-term renal function decline, which will be important for future study.

Analysis of the diverse antigenic landscape of the malaria protein RH5 identifies a potent vaccine-induced human public antibody clonotype.

The highly conserved and essential Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) has emerged as the leading target for vaccines against the disease-causing blood stage of malaria. However, the features of the human vaccine-induced antibody response that confer highly potent inhibition of malaria parasite invasion into red blood cells are not well defined. Here, we characterize 236 human IgG monoclonal antibodies, derived from 15 donors, induced by the most advanced PfRH5 vaccine. We define the antigenic landscape of this molecule and establish that epitope specificity, antibody association rate, and intra-PfRH5 antibody interactions are key determinants of functional anti-parasitic potency. In addition, we identify a germline IgG gene combination that results in an exceptionally potent class of antibody and demonstrate its prophylactic potential to protect against P. falciparum parasite challenge in vivo. This comprehensive dataset provides a framework to guide rational design of next-generation vaccines and prophylactic antibodies to protect against blood-stage malaria.

Regulation of a single inositol 1-phosphate synthase homeologue by HSFA6B contributes to fibre yield maintenance under drought conditions in upland cotton.

Drought stress substantially impacts crop physiology resulting in alteration of growth and productivity. Understanding the genetic and molecular crosstalk between stress responses and agronomically important traits such as fibre yield is particularly complicated in the allopolyploid species, upland cotton (Gossypium hirsutum), due to reduced sequence variability between A and D subgenomes. To better understand how drought stress impacts yield, the transcriptomes of 22 genetically and phenotypically diverse upland cotton accessions grown under well-watered and water-limited conditions in the Arizona low desert were sequenced. Gene co-expression analyses were performed, uncovering a group of stress response genes, in particular transcription factors GhDREB2A-A and GhHSFA6B-D, associated with improved yield under water-limited conditions in an ABA-independent manner. DNA affinity purification sequencing (DAP-seq), as well as public cistrome data from Arabidopsis, were used to identify targets of these two TFs. Among these targets were two lint yield-associated genes previously identified through genome-wide association studies (GWAS)-based approaches, GhABP-D and GhIPS1-A. Biochemical and phylogenetic approaches were used to determine that GhIPS1-A is positively regulated by GhHSFA6B-D, and that this regulatory mechanism is specific to Gossypium spp. containing the A (old world) genome. Finally, an SNP was identified within the GhHSFA6B-D binding site in GhIPS1-A that is positively associated with yield under water-limiting conditions. These data lay out a regulatory connection between abiotic stress and fibre yield in cotton that appears conserved in other systems such as Arabidopsis.

Insect Flight: State of the Field and Future Directions.

The evolution of flight in an early winged insect ancestral lineage is recognized as a key adaptation explaining the unparalleled success and diversification of insects. Subsequent transitions and modifications to flight machinery, including secondary reductions and losses, also play a central role in shaping the impacts of insects on broadscale geographic and ecological processes and patterns in the present and future. Given the importance of insect flight, there has been a centuries-long history of research and debate on the evolutionary origins and biological mechanisms of flight. Here, we revisit this history from an interdisciplinary perspective, discussing recent discoveries regarding the developmental origins, physiology, biomechanics, and neurobiology and sensory control of flight in a diverse set of insect models. We also identify major outstanding questions yet to be addressed and provide recommendations for overcoming current methodological challenges faced when studying insect flight, which will allow the field to continue to move forward in new and exciting directions. By integrating mechanistic work into ecological and evolutionary contexts, we hope that this synthesis promotes and stimulates new interdisciplinary research efforts necessary to close the many existing gaps about the causes and consequences of insect flight evolution.

Automatic Speech Recognition of Conversational Speech in Individuals With Disordered Speech.

PURPOSE: This study examines the effectiveness of automatic speech recognition (ASR) for individuals with speech disorders, addressing the gap in performance between read and conversational ASR. We analyze the factors influencing this disparity and the effect of speech mode-specific training on ASR accuracy. METHOD: Recordings of read and conversational speech from 27 individuals with various speech disorders were analyzed using both (a) one speaker-independent ASR system trained and optimized for typical speech and (b) multiple ASR models that were personalized to the speech of the participants with disordered speech. Word error rates were calculated for each speech model, read versus conversational, and subject. Linear mixed-effects models were used to assess the impact of speech mode and disorder severity on ASR accuracy. We investigated nine variables, classified as technical, linguistic, or speech impairment factors, for their potential influence on the performance gap. RESULTS: We found a significant performance gap between read and conversational speech in both personalized and unadapted ASR models. Speech impairment severity notably impacted recognition accuracy in unadapted models for both speech modes and in personalized models for read speech. Linguistic attributes of utterances were the most influential on accuracy, though atypical speech characteristics also played a role. Including conversational speech samples in model training notably improved recognition accuracy. CONCLUSIONS: We observed a significant performance gap in ASR accuracy between read and conversational speech for individuals with speech disorders. This gap was largely due to the linguistic complexity and unique characteristics of speech disorders in conversational speech. Training personalized ASR models using conversational speech significantly improved recognition accuracy, demonstrating the importance of domain-specific training and highlighting the need for further research into ASR systems capable of handling disordered conversational speech effectively.

Atrioventricular Synchrony Delivered by a Dual-Chamber Leadless Pacemaker System.

BACKGROUND: A dual-chamber leadless pacemaker system has been designed for AV synchronous pacing using wireless, beat-to-beat, implant-to-implant (i2i) communication between distinct atrial and ventricular leadless pacemakers. The AV synchrony achieved across various ambulatory scenarios has yet to be systematically evaluated. METHODS: A prospective, single-arm, unblinded, multicenter, international clinical trial of the leadless pacemaker system was conducted in patients with a conventional dual-chamber pacing indication enrolled from February 2022 to March 2023. Leadless pacemaker systems were implanted, and 12-lead Holter electrocardiographic recordings were collected 3 months after implantation over various postures/activities: sitting, supine, left lateral recumbent, right lateral recumbent, standing, normal walk, and fast walk. An independent Holter core laboratory performed a manual adjudication of the percent of AV synchronous beats using the standard 300-millisecond PR interval limit. Atrium-to-ventricle and ventricle-to-atrium i2i communication success rates were also assessed. Post hoc summary statistics describing the relationships between AV synchrony and i2i success, posture/activity, implantation indication, AV event, and heart rate were calculated. RESULTS: In the evaluable population (n=384 of 464 enrolled [83%]; 61% male; age, 70 years; weight, 82 kg; 60% ejection fraction; 95% of beats evaluable), the mean AV synchrony of 98% of beats observed across all postures using the standard 300-millisecond limit was greater than both atrium-to-ventricle i2i (94%) and ventricle-to-atrium i2i (94%; P<0.001), exceeding both i2i values in 95% of patients. AV synchrony was achieved in >95% of evaluable beats across all postures/activities, implantation indications, AV paced/sensed event combinations, and heart rate ranges (including >100 bpm). CONCLUSIONS: This dual-chamber leadless pacemaker system demonstrated AV synchrony in 98% of evaluable beats at 3 months after implantation. AV synchrony was maintained across postures/activities and remained robust for heart rates >100 bpm.

Patellar Resurfacing Is Not a Risk Factor for Postoperative Patella Baja in Total Knee Arthroplasty.

Background: Patella baja is a known complication of total knee arthroplasty (TKA). There is a limited understanding of the association between patellar resurfacing and the incidence of patella baja. We aimed to compare rates of patella baja between unresurfaced and resurfaced patellas in patients undergoing TKA. Methods: A retrospective review of patients who underwent TKA between October 2009 and January 2020 was performed. Patients were included if they had at least one preoperative radiograph and a 1-year follow-up radiograph. Blackburne-Peel index (BPI) and Insall-Salvati ratios (ISRs) were measured on preoperative and 1-year postoperative radiographs and were used to define patella baja vs pseudopatella baja. Statistical analysis was performed using a linear model analysis of variance and the Fisher's exact test. Results: Three hundred eighteen TKAs were included, with 176 being resurfaced and 142 unresurfaced patellas. Of the resurfaced group, 4% (7/176) had true patella baja, compared to 5.6% (8/142) of the unresurfaced patellas. Of the resurfaced patellas, 8% (14/176) had pseudopatella baja, compared to 7% (10/142) in the unresurfaced group. Patellar resurfacing was not associated with a higher incidence of patella baja (P = .60) or pseudopatella baja (P = .83). Lower preoperative ISRs (P = .04) and BPIs (0.03) were highly predictive of a higher incidence of patella baja post-TKA. Conclusions: Patellar resurfacing in TKA is not associated with a higher incidence of patella baja in TKA when compared to unresurfaced patellas. Lower preoperative ISRs and BPIs are highly predictive of a higher incidence of postoperative patella baja.

Central nervous system active medication use in Medicare enrollees receiving home health care: association with chronic pain and anxiety level.

ABSTRACT: No comparative effectiveness data exist on nonopioid analgesics and nonbenzodiazepine anxiolytics to treat pain with anxiety. We examined the relationship between drug class and central nervous system (CNS) active drug polypharmacy on pain and anxiety levels in Medicare enrollees receiving home health (HH) care. This retrospective cohort study included enrollees with diagnoses and 2+ assessments of pain and anxiety between HH admission and discharge. Three sets of linear regression difference-in-reduction analyses assessed the association of pain or anxiety reduction with number of drugs; drug type; and drug combinations in those with daily pain and daily anxiety. Logistic regression analysis assessed the effect of medication number and class on less-than-daily pain or anxiety at HH discharge. A sensitivity analysis using multinomial regression was conducted with a three-level improvement to further determine clinical significance. Of 85,403 HH patients, 43% received opioids, 27% benzodiazepines, 26% gabapentinoids, 32% selective serotonin reuptake inhibitors, and 8% serotonin and norepinephrine reuptake inhibitors (SNRI). Furthermore, 75% had depression, 40% had substance use disorder diagnoses, and 6.9% had PTSD diagnoses. At HH admission, 83%, 35%, and 30% of patients reported daily pain, daily anxiety, and both, respectively. Central nervous system polypharmacy was associated with worse pain control and had no significant effect on anxiety. For patients with daily pain plus anxiety, pain was best reduced with one medication or any drug combination without opioid/benzodiazepine; anxiety was best reduced with combinations other than opiate/benzodiazepine. Gabapentinoids or SNRI achieved clinically meaningful pain control. Selective serotonin reuptake inhibitors provided clinically meaningful anxiety relief.

Preclinical development of a stabilized RH5 virus-like particle vaccine that induces improved antimalarial antibodies.

Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is a leading blood-stage malaria vaccine antigen target, currently in a phase 2b clinical trial as a full-length soluble protein/adjuvant vaccine candidate called RH5.1/Matrix-M. We identify that disordered regions of the full-length RH5 molecule induce non-growth inhibitory antibodies in human vaccinees and that a re-engineered and stabilized immunogen (including just the alpha-helical core of RH5) induces a qualitatively superior growth inhibitory antibody response in rats vaccinated with this protein formulated in Matrix-M adjuvant. In parallel, bioconjugation of this immunogen, termed "RH5.2," to hepatitis B surface antigen virus-like particles (VLPs) using the "plug-and-display" SpyTag-SpyCatcher platform technology also enables superior quantitative antibody immunogenicity over soluble protein/adjuvant in vaccinated mice and rats. These studies identify a blood-stage malaria vaccine candidate that may improve upon the current leading soluble protein vaccine candidate RH5.1/Matrix-M. The RH5.2-VLP/Matrix-M vaccine candidate is now under evaluation in phase 1a/b clinical trials.

Consensus Statement: Technical Standards for Thoracoabdominal Normothermic Regional Perfusion.

BACKGROUND: Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a powerful technique for optimizing organ procurement from donation after circulatory death donors. Despite its rapid adoption, standardized guidelines for TA-NRP implementation are lacking, prompting the need for consensus recommendations to ensure safe and effective utilization of this technique. METHODS: A working group composed of members from The American Society of Transplant Surgeons, The International Society of Heart and Lung Transplantation, The Society of Thoracic Surgeons, and The American Association for Thoracic Surgery was convened to develop technical guidelines for TA-NRP. The group systematically reviewed existing literature, consensus statements, and expert opinions to identify key areas requiring standardization, including predonation evaluation, intraoperative management, postdonation procedures, and future research directions. RESULTS: The working group formulated recommendations encompassing donor evaluation and selection criteria, premortem testing and therapeutic interventions, communication protocols, and procedural guidelines for TA-NRP implementation. These recommendations aim to facilitate coordination among transplant teams, minimize variability in practice, and promote transparency and accountability throughout the TA-NRP process. CONCLUSIONS: The consensus guidelines presented herein serve as a comprehensive framework for the successful and ethical implementation of TA-NRP programs in organ procurement from donation after circulatory death donors. By providing standardized recommendations and addressing areas of uncertainty, these guidelines aim to enhance the quality, safety, and efficiency of TA-NRP procedures, ultimately contributing to improved outcomes for transplant recipients.

Patient Interest in Quadriceps Autograft Anterior Cruciate Ligament Reconstruction Is Increasing Over Other Autograft Options: A 12-Year Google Trends Analysis.

Purpose: To use Google trends to explore differences in public interest among types of anterior cruciate ligament (ACL) autografts, specifically quadriceps tendon, patellar tendon, and hamstring tendon autografts, between 2008 and 2019. Methods: Data were obtained by querying Google Trends for key terms and phrases for online search data ranging from January 2008 to December 2019. Relative search volumes were created based on searches related to ACL reconstruction with comparative analysis generated for search terms related to quadriceps ACL, patellar tendon ACL, and hamstring ACL autografts. Statistical analysis included linear regression analysis, comparison of quarterly search volume trends over time, and comparison of cumulative annual search volumes for 2008 versus 2019. Results: Linear models for respective search terms were statistically significant for the quadriceps (P < .001) and patellar (P = .007) tendon autograft groups but not the hamstring group (P = .129). The quadriceps autograft group demonstrated a 12-year search volume trend change of 0.56, which was significantly greater than the hamstring (0.07; P < .001) and patellar tendon (0.168; P < .001) groups. There was no significant difference in the trend change between hamstring and patellar tendon groups (P = .20). Percent change in cumulative relative annual search volumes between 2008 and 2019 was 112% for the quadriceps tendon group, 12.9% for the hamstring group, and 18.6% for the patellar tendon group. Conclusions: This study indicates a consistently increasing public interest in quadriceps tendon autograft for ACL reconstruction. The quadriceps autograft group demonstrated a significantly greater 12-year online search volume, greater linear correlation, and larger percent change between 2008 and 2019 compared with patellar tendon or hamstring autograft groups. Clinical Relevance: Awareness of patient perceptions has value in informing shared decision-making, aligning patient expectations, and guiding areas of future research. Each of these has an impact on patient care. Being aware of patient interest and expectations is particularly important in areas with controversial or emerging research.

Neurovascular coupling, functional connectivity, and cerebrovascular endothelial extracellular vesicles as biomarkers of mild cognitive impairment.

INTRODUCTION: Mild cognitive impairment (MCI) is a prodromal stage of dementia. Understanding the mechanistic changes from healthy aging to MCI is critical for comprehending disease progression and enabling preventative intervention. METHODS: Patients with MCI and age-matched controls (CN) were administered cognitive tasks during functional near-infrared spectroscopy (fNIRS) recording, and changes in plasma levels of extracellular vesicles (EVs) were assessed using small-particle flow cytometry. RESULTS: Neurovascular coupling (NVC) and functional connectivity (FC) were decreased in MCI compared to CN, prominently in the left-dorsolateral prefrontal cortex (LDLPFC). We observed an increased ratio of cerebrovascular endothelial EVs (CEEVs) to total endothelial EVs in patients with MCI compared to CN, correlating with structural MRI small vessel ischemic damage in MCI. LDLPFC NVC, CEEV ratio, and LDLPFC FC had the highest feature importance in the random Forest group classification. DISCUSSION: NVC, CEEVs, and FC predict MCI diagnosis, indicating their potential as markers for MCI cerebrovascular pathology. HIGHLIGHTS: Neurovascular coupling (NVC) is impaired in mild cognitive impairment (MCI). Functional connectivity (FC) compensation mechanism is lost in MCI. Cerebrovascular endothelial extracellular vesicles (CEEVs) are increased in MCI. CEEV load strongly associates with cerebral small vessel ischemic lesions in MCI. NVC, CEEVs, and FC predict MCI diagnosis over demographic and comorbidity factors.

Precision-guided treatment in high-risk pediatric cancers.

Recent research showed that precision medicine can identify new treatment strategies for patients with childhood cancers. However, it is unclear which patients will benefit most from precision-guided treatment (PGT). Here we report consecutive data from 384 patients with high-risk pediatric cancer (with an expected cure rate of less than 30%) who had at least 18 months of follow-up on the ZERO Childhood Cancer Precision Medicine Program PRecISion Medicine for Children with Cancer (PRISM) trial. A total of 256 (67%) patients received PGT recommendations and 110 (29%) received a recommended treatment. PGT resulted in a 36% objective response rate and improved 2-year progression-free survival compared with standard of care (26% versus 12%; P = 0.049) or targeted agents not guided by molecular findings (26% versus 5.2%; P = 0.003). PGT based on tier 1 evidence, PGT targeting fusions or commenced before disease progression had the greatest clinical benefit. Our data show that PGT informed by comprehensive molecular profiling significantly improves outcomes for children with high-risk cancers. ClinicalTrials.gov registration: NCT03336931.

Listener effort quantifies clinically meaningful progression of dysarthria in people living with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative motor neuron disease that causes progressive muscle weakness. Progressive bulbar dysfunction causes dysarthria and thus social isolation, reducing quality of life. The Everything ALS Speech Study obtained longitudinal clinical information and speech recordings from 292 participants. In a subset of 120 participants, we measured speaking rate (SR) and listener effort (LE), a measure of dysarthria severity rated by speech pathologists from recordings. LE intra- and inter-rater reliability was very high (ICC 0.88 to 0.92). LE correlated with other measures of dysarthria at baseline. LE changed over time in participants with ALS (slope 0.77 pts/month; p<0.001) but not controls (slope 0.005 pts/month; p=0.807). The slope of LE progression was similar in all participants with ALS who had bulbar dysfunction at baseline, regardless of ALS site of onset. LE could be a remotely collected clinically meaningful clinical outcome assessment for ALS clinical trials.

Blood-stage malaria vaccine candidate RH5.1/Matrix-M in healthy Tanzanian adults and children; an open-label, non-randomised, first-in-human, single-centre, phase 1b trial.

BACKGROUND: A blood-stage Plasmodium falciparum malaria vaccine would provide a second line of defence to complement partially effective or waning immunity conferred by the approved pre-erythrocytic vaccines. RH5.1 is a soluble protein vaccine candidate for blood-stage P falciparum, formulated with Matrix-M adjuvant to assess safety and immunogenicity in a malaria-endemic adult and paediatric population for the first time. METHODS: We did a non-randomised, phase 1b, single-centre, dose-escalation, age de-escalation, first-in-human trial of RH5.1/Matrix-M in Bagamoyo, Tanzania. We recruited healthy adults (aged 18-45 years) and children (aged 5-17 months) to receive the RH5.1/Matrix-M vaccine candidate in the following three-dose regimens: 10 µg RH5.1 at 0, 1, and 2 months (Adults 10M), and the higher dose of 50 µg RH5.1 at 0 and 1 month and 10 µg RH5.1 at 6 months (delayed-fractional third dose regimen; Adults DFx). Children received either 10 µg RH5.1 at 0, 1, and 2 months (Children 10M) or 10 µg RH5.1 at 0, 1, and 6 months (delayed third dose regimen; Children 10D), and were recruited in parallel, followed by children who received the dose-escalation regimen (Children DFx) and children with higher malaria pre-exposure who also received the dose-escalation regimen (High Children DFx). All RH5.1 doses were formulated with 50 µg Matrix-M adjuvant. Primary outcomes for vaccine safety were solicited and unsolicited adverse events after each vaccination, along with any serious adverse events during the study period. The secondary outcome measures for immunogenicity were the concentration and avidity of anti-RH5.1 serum IgG antibodies and their percentage growth inhibition activity (GIA) in vitro, as well as cellular immunogenicity to RH5.1. All participants receiving at least one dose of vaccine were included in the primary analyses. This trial is registered at ClinicalTrials.gov, NCT04318002, and is now complete. FINDINGS: Between Jan 25, 2021, and April 15, 2021, we recruited 12 adults (six [50%] in the Adults 10M group and six [50%] in the Adults DFx group) and 48 children (12 each in the Children 10M, Children 10D, Children DFx, and High Children DFx groups). 57 (95%) of 60 participants completed the vaccination series and 55 (92%) completed 22 months of follow-up following the third vaccination. Vaccinations were well-tolerated across both age groups. There were five serious adverse events involving four child participants during the trial, none of which were deemed related to vaccination. RH5-specific T cell and serum IgG antibody responses were induced by vaccination and purified total IgG showed in vitro GIA against P falciparum. We found similar functional quality (ie, GIA per µg RH5-specific IgG) across all age groups and dosing regimens at 14 days after the final vaccination; the concentration of RH5.1-specific polyclonal IgG required to give 50% GIA was 14·3 µg/mL (95% CI 13·4-15·2). 11 children were vaccinated with the delayed third dose regimen and showed the highest median anti-RH5 serum IgG concentration 14 days following the third vaccination (723 µg/mL [IQR 511-1000]), resulting in all 11 who received the full series showing greater than 60% GIA following dilution of total IgG to 2·5 mg/mL (median 88% [IQR 81-94]). INTERPRETATION: The RH5.1/Matrix-M vaccine candidate shows an acceptable safety and reactogenicity profile in both adults and 5-17-month-old children residing in a malaria-endemic area, with all children in the delayed third dose regimen reaching a level of GIA previously associated with protective outcome against blood-stage P falciparum challenge in non-human primates. These data support onward efficacy assessment of this vaccine candidate against clinical malaria in young African children. FUNDING: The European and Developing Countries Clinical Trials Partnership; the UK Medical Research Council; the UK Department for International Development; the National Institute for Health and Care Research Oxford Biomedical Research Centre; the Division of Intramural Research, National Institute of Allergy and Infectious Diseases; the US Agency for International Development; and the Wellcome Trust.

Assessing the Racial and Ethnic Diversity of Physician Assistant/Associate Program Graduates from 2010 to 2012 and 2019 to 2021.

INTRODUCTION: To assess the racial/ethnic diversity of graduates of US Physician Assistant/Associate (PA) programs compared with the diversity of the populations from which they draw students and to assess diversity changes over time among PA graduates. METHODS: We calculated proportion of Black or Hispanic PA graduates nationally and by school between 2010 to 2012 and 2019 to 2021 using the Integrated Postsecondary Education Data System (IPEDS) and compared it with the diversity of the 20 to 35-year-old population using the American Community Survey. We created benchmark populations for each school based on whether the school was public or private, with in-state/out-of-state proportions provided by the Physician Assistant Education Association. A diversity index (DI) was calculated for each program. A DI of 0.5 means that the representation of Black/Hispanic graduates is half their representation in the benchmark population. RESULTS: Although the numbers of Black/Hispanic graduates increased from 2010 to 2012 to 2019 to 2021, the percentage of Black graduates decreased. Nationally, the DI for Black graduates decreased from 0.28 to 0.23 and the Hispanic DI increased from 0.28 to 0.37 between 2010 to 2012 and 2019 to 2021. Among 213 PA programs included in the 2019 to 2021 dataset, 5 schools had a DI >1.0 for Black graduates and 7 schools had a DI >1.0 for Hispanic graduates. DISCUSSION: Using the IPEDS data, we found that Black and Hispanic graduates are underrepresented among PA program graduates. The PA education community needs to develop new strategies for diversifying the profession consistent with the new US Supreme Court decision banning race-conscious admissions.