Insights on the G protein-coupled receptor helix 8 solution structure and orientation using a neurotensin receptor 1 peptide.

G-protein coupled receptors (GPCRs) are the largest class of membrane proteins encoded in the human genome with high pharmaceutical relevance and implications to human health. These receptors share a prevalent architecture of seven transmembrane helices followed by an intracellular, amphipathic helix 8 (H8) and a disordered C-terminal tail (Ctail). Technological advancements have led to over 1000 receptor structures in the last two decades, yet frequently H8 and the Ctail are conformationally heterogeneous or altogether absent. Here we synthesize a peptide comprising the neurotensin receptor 1 (NTS1) H8 and Ctail (H8-Ctail) to investigate its structural stability, conformational dynamics, and orientation in the presence of detergent and phospholipid micelles, which mimic the membrane. Circular dichroism (CD) and nuclear magnetic resonance (NMR) measurements confirm that zwitterionic 1,2-diheptanoyl-sn-glycero-3-phosphocholine is a potent stabilizer of H8 structure, whereas the commonly-used branched detergent lauryl maltose neopentyl glycol (LMNG) is unable to completely stabilize the helix - even at amounts four orders of magnitude greater than its critical micellar concentration. We then used NMR spectroscopy to assign the backbone chemical shifts. A series of temperature and lipid titrations were used to define the H8 boundaries as F376-R392 from chemical shift perturbations, changes in resonance intensity, and chemical-shift-derived phi/psi angles. Finally, the H8 azimuthal and tilt angles, defining the helix orientation relative of the membrane normal were measured using paramagnetic relaxation enhancement NMR. Taken together, our studies reveal the H8-Ctail region is sensitive to membrane physicochemical properties and is capable of more adaptive behavior than previously suggested by static structural techniques.

Cryptic diversity within two widespread diadromous freshwater fishes (Teleostei: Galaxiidae).

Identification of taxonomically cryptic species is essential for the effective conservation of biodiversity. Freshwater-limited organisms tend to be genetically isolated by drainage boundaries, and thus may be expected to show substantial cryptic phylogenetic and taxonomic diversity. By comparison, populations of diadromous taxa, that migrate between freshwater and marine environments, are expected to show less genetic differentiation. Here we test for cryptic diversity in Australasian populations (both diadromous and non-diadromous) of two widespread Southern Hemisphere fish species, Galaxias brevipinnis and Galaxias maculatus. Both mtDNA and nuclear markers reveal putative cryptic species within these taxa. The substantial diversity detected within G. brevipinnis may be explained by its strong climbing ability which allows it to form isolated inland populations. In island populations, G. brevipinnis similarly show deeper genetic divergence than those of G. maculatus, which may be explained by the greater abundance of G. maculatus larvae in the sea allowing more ongoing dispersal. Our study highlights that even widespread, 'high-dispersal' species can harbour substantial cryptic diversity and therefore warrant increased taxonomic and conservation attention.

Quantum Mechanical Assessment of Nitrosamine Potency.

Nitrosamines are in the cohort of concern (CoC) as determined by regulatory guidance. CoC compounds are considered highly potent carcinogens that need to be limited below the threshold of toxicological concern, 1.5 µg/day. Nitrosamines like NDMA and NDEA require strict control, while novel nitrosamine drug substance-related impurities (NDSRIs) may or may not be characterized as potent carcinogens. A risk assessment based on the structural features of NDSRIs is important in order to predict potency because they lack substance-specific carcinogenicity. Herein, we present a quantum mechanical (QM)-based analysis on structurally diverse sets of nitrosamines to better understand how structure influences the reactivity that could result in carcinogenicity. We describe the potency trend through activation energies corresponding to α-hydroxylation, aldehyde formation, diazonium intermediate formation, reaction with DNA base, and hydrolysis reactions, and other probable metabolic pathways associated with the carcinogenicity of nitrosamines. We evaluated activation energies for selected cases such as N-nitroso pyrrolidines, N-nitroso piperidines, N-nitroso piperazines, N-nitroso morpholines, N-nitroso thiomorpholine, N-methyl nitroso aromatic, fluorine-substituted nitrosamines, and substituted aliphatic nitrosamines. We compare these results to the recent framework of the carcinogenic potency characterization approach (CPCA) proposed by health authorities which is meant to give guidance on acceptable intakes (AI) for NDSRIs lacking substance-specific carcinogenicity data. We show examples where QM modeling and CPCA are aligned and examples where CPCA both underestimates and overestimates the AI. In cases where CPCA predicts high potency for NDSRIs, QM modeling can help better estimate an AI. Our results suggest that a combined mechanistic understanding of α-hydroxylation, aldehyde formation, hydrolysis, and reaction with DNA bases could help identify the structural features that underpin the potency of nitrosamines. We anticipate this work will be a valuable addition to the CPCA and provide a more analytical way to estimate AI for novel NDSRIs.

Phospholipid isotope tracing suggests ß-catenin-driven suppression of phosphatidylcholine metabolism in hepatocellular carcinoma.

Activating mutations in the CTNNB1 gene encoding ß-catenin are among the most frequently observed oncogenic alterations in hepatocellular carcinoma (HCC). Profound alterations in lipid metabolism, including increases in fatty acid oxidation and transformation of the phospholipidome, occur in HCC with CTNNB1 mutations, but it is unclear what mechanisms give rise to these changes. We employed untargeted lipidomics and targeted isotope tracing to measure phospholipid synthesis activity in an inducible human liver cell line expressing mutant ß-catenin, as well as in transgenic zebrafish with activated ß-catenin-driven HCC. In both models, activated ß-catenin expression was associated with large changes in the lipidome including conserved increases in acylcarnitines and ceramides and decreases in triglycerides. Lipid isotope tracing analysis in human cells revealed a reduction in phosphatidylcholine (PC) production rates as assayed by choline incorporation. We developed lipid isotope tracing analysis for zebrafish tumors and observed reductions in phosphatidylcholine synthesis by both the CDP-choline and PEMT pathways. The observed changes in the ß-catenin-driven HCC phospholipidome suggest that zebrafish can recapitulate conserved features of HCC lipid metabolism and may serve as a model for identifying future HCC-specific lipid metabolic targets.

AAV-mediated gene therapy for Sialidosis.

Sialidosis (Mucolipidosis I) is a glycoprotein storage disease, clinically characterized by a spectrum of systemic and neurological phenotypes. The primary cause of the disease is deficiency of the lysosomal sialidase NEU1, resulting in accumulation of sialylated glycoproteins/ oligosaccharides in tissues and body fluids. Neu1-/- mice recapitulate the severe, early-onset forms of the disease, affecting visceral organs, muscles, and the nervous system, with wide-spread lysosomal vacuolization evident in most cell types. Sialidosis is considered an orphan disorder with no therapy currently available. Here, we assessed the therapeutic potential of AAV-mediated gene therapy for the treatment of sialidosis. Neu1-/- mice were co-injected with two scAAV2/8 vectors, expressing human NEU1 and its chaperone PPCA. Treated mice were phenotypically indistinguishable from their WT controls. NEU1 activity was restored to different extent in most tissues, including the brain, heart and muscle, and visceral organs. This resulted in diminished/absent lysosomal vacuolization in multiple cell types and reversal of sialyl-oligosacchariduria. Lastly, normalization of lysosomal exocytosis in the CSF and serum of treated mice, coupled to diminished neuroinflammation, were measures of therapeutic efficacy. These findings point to AAV-mediated gene therapy as a suitable treatment for sialidosis and possibly other diseases, associated with low NEU1 expression.

"If You Plant That Seed, It Will Grow": A Qualitative Study to Improve Linkage to Care among Patients with Methamphetamine Use Disorder in Emergency Department Settings.

OBJECTIVES: Methamphetamine addiction is a serious and difficult-to-treat disorder. Existing treatment options are limited, and patient perspectives on effective strategies are lacking. Emergency departments (EDs) may be a critical entry point for individuals with methamphetamine use disorder (MUD) to be identified and linked to treatment. We aimed to understand patients' perspectives regarding their methamphetamine use and related ED experiences and how to improve linkage to substance treatment. METHODS: Between July and November 2022, semistructured qualitative interviews were conducted with adult patients with MUD in an urban safety-net healthcare setting in Denver, Colorado. Interviews were recorded, summarized, and analyzed using the Rapid Assessment Process. RESULTS: During the interviews, 18 patients shared their experiences. Participants described feeling stigmatized and experiencing a lack of communication from ED staff during their visit. Additionally, participants shared the perception that ED staff often did not take their health concerns seriously once substance use was identified. Participants were uncertain about overdose risk and felt that their psychiatric symptoms complicated treatment. Referrals to treatment were lacking, and participants supported a care navigation intervention that incorporates elements of contingency management. Participants also shared the importance of ED staff recognizing their social needs and being empathetic, trauma-informed, and flexible to meet patients where they are regardless of their readiness to seek treatment. CONCLUSIONS: Treatment options and entry points for individuals with MUD are currently limited. The patient perspectives described here are helpful in developing services to support, engage, and link individuals to MUD services after discharge from ED services.

Establishing Neural Organoid Cultures for Investigating the Effects of Microgravity in Low-Earth Orbit (LEO).

Recent findings from studies involving astronauts and animal models indicate that microgravity increases immune cell activity and potentially alters the white and gray matter of the central nervous system (CNS). To further investigate the impact of microgravity on CNS cells, we established cultures of three-dimensional neural organoids containing isogenic microglia, the brain's resident immune cells, and sent them onboard the International Space Station. When using induced pluripotent stem cell (iPSC) lines from individuals affected by neuroinflammatory and neurodegenerative diseases such as multiple sclerosis (MS) and Parkinson's disease (PD), these cultures can provide novel insights into pathogenic pathways that may be exacerbated by microgravity. We have devised a cryovial culture strategy that enables organoids to be maintained through space travel and onboard the International Space Station (ISS) without the need for medium or carbon dioxide exchange. Here, we provide a comprehensive description of all the steps involved: generating various types of neural organoids, establishing long-term cultures, arranging plans for shipment to the Kennedy Space Center (KSC), and ultimately preparing organoids for launch into low-Earth orbit (LEO) and return to Earth for post-flight analyses.

Diagnosis of methamphetamine-induced psychotic disorder: Findings of an expert consensus panel.

AIM: We define criteria for methamphetamine-induced psychotic disorder (MIPD) to aid in accurate and reliable diagnosis. METHOD: An expert panel was recruited and engaged in an iterative consensus process. A literature search supported this work. The a priori level for consensus was considered ≥80% of voting panellists. RESULTS: The final expert panel included 22 physicians from different backgrounds and practice environments. The panel produced two consensus diagnoses: (1) acute MIPD and (2) persisting MIPD, which is further separated into subacute and chronic timeframes. Although certain characteristics differentiate methamphetamine-induced psychosis shortly after use, identification of persisting MIPD depends largely on a history of symptom onset. All respondents voted in the final round, and both criteria were fully endorsed by 91% (20/22) of respondents. Panellists further recommended next steps in validation and research on this topic. CONCLUSION: These diagnostic criteria aid clinicians in differentiating methamphetamine-induced psychotic symptoms from psychosis because of other psychiatric disorders and can guide future studies. Future research might examine these criteria's prognostic significance, interrater reliability and acceptability including among persons in recovery. This work is a necessary and vital step in advancing the science of methamphetamine addiction treatment.

Perioperative Nutritional, Functional, and Bone Health Optimization in Spine Surgery: A National Investigation of Spine Surgeons' Perceptions and Practices.

INTRODUCTION: While perioperative nutritional, functional, and bone health status optimization in spine surgery is supported with ample evidence, the implementation and surgeon perception regarding such efforts in clinical practice remain largely unexplored. This study sought to assess the current perception of spine surgeons and implementation regarding the nutritional, functional status, and bone health perioperative optimization. METHODS: An anonymous 30-question survey was distributed to orthopaedic spine fellowship and neurosurgery program directors identified through the North American Spine Society and American Association of Neurological Surgeons contact databases. RESULTS: The questionnaire was completed by 51 surgeon survey respondents. Among those, 62% reported no current formal nutritional optimization protocols with 14% not recommending an optimization plan, despite only 10% doubting benefits of nutritional optimization. While 5% of respondents perceived functional status optimization as nonbeneficial, 68% of respondents reported no protocol in place and 46% noted a functional status assessment relying on patient dependency. Among the respondents, 85% routinely ordered DEXA scan if there was suspicion of osteoporosis and 85% usually rescheduled surgery if bone health optimization goals were not achieved while 6% reported being suspicious of benefit from such interventions. CONCLUSION: While most responding spine surgeons believe in the benefit of perioperative nutritional and functional optimization, logistical and patient compliance challenges were noted as critical barriers toward optimization. Understanding surgeon perception and current practices may guide future efforts toward advancement of optimization protocols.

Brain activity during reappraisal and associations with psychotherapy response in social anxiety and major depression: a randomized trial.

BACKGROUND: Cognitive behavioral therapy (CBT) is an effective treatment for patients with social anxiety disorder (SAD) or major depressive disorder (MDD), yet there is variability in clinical improvement. Though prior research suggests pre-treatment engagement of brain regions supporting cognitive reappraisal (e.g. dorsolateral prefrontal cortex [dlPFC]) foretells CBT response in SAD, it remains unknown if this extends to MDD or is specific to CBT. The current study examined associations between pre-treatment neural activity during reappraisal and clinical improvement in patients with SAD or MDD following a trial of CBT or supportive therapy (ST), a common-factors comparator arm. METHODS: Participants were 75 treatment-seeking patients with SAD (n = 34) or MDD (n = 41) randomized to CBT (n = 40) or ST (n = 35). Before randomization, patients completed a cognitive reappraisal task during functional magnetic resonance imaging. Additionally, patients completed clinician-administered symptom measures and a self-report cognitive reappraisal measure before treatment and every 2 weeks throughout treatment. RESULTS: Results indicated that pre-treatment neural activity during reappraisal differentially predicted CBT and ST response. Specifically, greater trajectories of symptom improvement throughout treatment were associated with less ventrolateral prefrontal cortex (vlPFC) activity for CBT patients, but more vlPFC activity for ST patients. Also, less baseline dlPFC activity corresponded with greater trajectories of self-reported reappraisal improvement, regardless of treatment arm. CONCLUSIONS: If replicated, findings suggest individual differences in brain response during reappraisal may be transdiagnostically associated with treatment-dependent improvement in symptom severity, but improvement in subjective reappraisal following psychotherapy, more broadly.

Probing Metal Ion Adduction in the ESI Charged Residue Mechanism via Gas-Phase Ion/Ion Chemistry.

The final stages of the charged residue mechanism/model (CRM) for ion generation via electrospray ionization (ESI) involves the binding of excess charge onto analyte species. Ions of both polarities can bind to the analyte with an excess of ions of the same polarity as the droplet. For large biomolecule/biocomplex ions, which are commonly the species of interest in native mass spectrometry (MS), the binding of acids and salts onto the analyte can lead to extensive broadening of ion signals due to adduction. Therefore, heating step(s) to facilitate desolvation and salt adduct removal are commonplace. In this work, we describe an approach to study the final stages of CRM using gas-phase ion/ion reactions to generate analyte ion/salt clusters of well-defined composition, followed by gas-phase collision-induced dissociation (CID). While there are many variables that can be studied systematically via this approach, the work described herein is focused on salt clusters of the form [Na10X11]-, where X = acetate (Ac-), chloride (Cl-), or nitrate (NO3-), in reaction with a common charge state of ubiquitin as well as several model peptides. Experiments in which equimolar quantities of each salt (i.e., NaAc, NaCl, and NaNO3) are subjected to ESI with ubiquitin (Ubi) and gas-phase ion/ion reaction studies involving [Na10X11]- and [Ubi + 6H]6+ show similar trends, in terms of the extent of sodium ion incorporation into the protein ions. Ion/ion reaction studies using model peptides show that the acetate-containing salt transfers significantly more Na+ ions into the peptide ions. Exchange of Na+ for H+ is shown to occur at the C-terminus and at up to all of the amide linkages using [Na10X11]-, whereas only the C-terminus engages in Na+/H+ exchange with [Na10Cl11]- and [Na10(NO3)11]-. In the latter cases, an additional Na+ is taken up as the excess positive charge, presumably due to solvation of the charge by multiple sites (e.g., carbonyl oxygens and basic sites).

Reconstruction for Congenital Absence of the Fifth Metacarpal.

We report a case of an isolated congenital absence of the right fifth metacarpal with ring and little finger syndactyly in a 6-year-old girl without other ipsilateral limb anomalies or phenotypic disorders. The patient underwent amputation of the hypoplastic right little finger with reconstruction of the ulnar collateral ligament of the ring finger metacarpophalangeal joint as well as hypothenar muscle transfer. She has returned to normal childhood activities without limitation at 3 months after surgery. Absence of the fifth metacarpal is a rare congenital anomaly without clear recommendations regarding reconstructive options. This case discussion supplements the current literature by describing an unusual presentation of this hand anomaly while supporting individualized management to maximize functional and cosmetic results.

CRISPR Dependency Screens in Primary Hematopoietic Stem Cells Identify KDM3B as a Genotype Specific Vulnerability in IDH2- and TET2-Mutant Cells.

Clonal hematopoiesis (CH) is a common premalignant state in the blood and confers an increased risk of blood cancers and all-cause mortality. Identification of therapeutic targets in CH has been hindered by the lack of an ex vivo platform amenable for studying primary hematopoietic stem and progenitor cells (HSPCs). Here, we utilize an ex vivo co-culture system of HSPCs with bone marrow endothelial cells to perform CRISPR/Cas9 screens in mutant HSPCs. Our data reveal that loss of the histone demethylase family members Kdm3b and Jmjd1c specifically reduces the fitness of Idh2- and Tet2-mutant HSPCs. Kdm3b loss in mutant cells leads to decreased expression of critical cytokine receptors including Mpl, rendering mutant HSPCs preferentially susceptible to inhibition of downstream JAK2 signaling. Our study nominates an epigenetic regulator and an epigenetically regulated receptor signaling pathway as genotype-specific therapeutic targets and provides a scalable platform to identify genetic dependencies in mutant HSPCs.

Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis: A Prospective Randomized Controlled Trial.

BACKGROUND: The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown. METHODS: In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications. RESULTS: A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration. CONCLUSIONS: Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Indigo-dyed cellulose fibers and synthetic polymers in surface-feeding seabird chick regurgitates from the Gulf of Alaska.

We provide evidence of anthropogenic materials ingestion in seabirds from a remote oceanic area, using regurgitates obtained from black-legged kittiwake (Rissa tridactyla) chicks from Middleton Island (Gulf of Alaska, USA). By means of GPS tracking of breeding adults, we identified foraging grounds where anthropogenic materials were most likely ingested. They were mainly located within the continental shelf of the Gulf of Alaska and near the Alaskan coastline. Anthropogenic cellulose fibers showed a high prevalence (85 % occurrence), whereas synthetic polymers (in the micro- and mesoplastics dimensional range) were less frequent (20 %). Most fibers (60 %) were blue and we confirmed the presence of indigo-dyed cellulosic fibers, characteristic of denim fabrics. In terms of mass, contamination levels were 0.077 µg g-1 wet weight and 0.009 µg g-1 wet weight for anthropogenic microfibers and synthetic polymers, respectively. These results represent the only recent report of contamination by anthropogenic fibers in seabirds from the Gulf of Alaska.

Salvage surgery for recurrent or residual hypopharyngeal squamous cell carcinoma: A systematic review.

BACKGROUND: This systematic review aggregates the data of studies that include site-specific analyses of patients undergoing salvage surgery for residual or recurrent hypopharyngeal squamous cell carcinoma. METHODS: The primary outcomes are disease-free, disease-specific, and overall survival (DFS, DSS, and OS, respectively). Secondary outcomes include complications and postoperative feeding requirements. RESULTS: Fifteen studies met the inclusion criteria with a total of 442 patients. Two-year DFS is reported from 30.0 to 50.0% and 5-year DFS ranges from 15.0 to 57.1%. Five-year DSS ranges from 28.0 to 57.1%. Two-year OS ranges from 38.8 to 52.0% and 5-year OS ranges from 15.5 to 57.1%. Complications include pharyngocutaneous fistula (0.0-71.4%), carotid artery rupture (2.9-13.3%), and stomal stenosis (4.2-20.0%). Complete oral feeding achieved following surgery ranges from 61.9 to 100.0%, while complete gastrostomy tube dependence ranges from 0.0 to 28.6%. CONCLUSIONS: Salvage surgery for residual or recurrent hypopharyngeal squamous cell carcinoma has a relatively high complication rate and should be offered to patients with the understanding of a guarded prognosis.

Restoration age affects microbial-herbaceous plant interactions in an oak woodland.

In degraded ecosystems, soil microbial communities (SMCs) may influence the outcomes of ecological restoration. Restoration practices can affect SMCs, though it is unclear how variation in the onset of restoration activities in woodlands affects SMCs, how those SMCs influence the performance of hard-to-establish woodland forbs, and how different woodland forbs shape SMCs. In this study, we quantified soil properties and species abundances in an oak woodland restoration chronosequence (young, intermediate, and old restorations). We measured the growth of three woodland forb species when inoculated with live whole-soil from young, intermediate, or old restorations. We used DNA metabarcoding to characterize SMCs of each inoculum treatment and the soil after conditioning by each plant species. Our goals were to (1) understand how time since the onset of restoration affected soil abiotic properties, plant communities, and SMCs in a restoration chronosequence, (2) test growth responses of three forb species to whole-soil inoculum from restoration sites, and (3) characterize changes in SMCs before and after conditioning by each forb species. Younger restored woodlands had greater fire-sensitive tree species and lower concentrations of soil phosphorous than intermediate or older restored woodlands. Bacterial and fungal soil communities varied significantly among sites. Forbs exhibited the greatest growth in soil from the young restoration. Each forb species developed a unique soil microbial community. Our results highlight how restoration practices affect SMCs, which can in turn affect the growth of hard-to-establish forb species. Our results also highlight that the choice of forb species can alter SMCs, which could have long-term potential consequences for restoration success.

Sociodemographic factors associated with vaccine hesitancy in the South Asian community in Canada.

OBJECTIVE: South Asians represent the largest non-white ethnic group in Canada and were disproportionately impacted by the COVID-19 pandemic. We sought to determine the factors associated with vaccine hesitancy in South Asian Canadians. METHODS: We conducted a cross-sectional analysis of vaccine hesitancy using data collected at the baseline assessment of a prospective cohort study, COVID CommUNITY South Asian. Participants (18 + years) were recruited from the Greater Toronto and Hamilton Area in Ontario (ON) and the Greater Vancouver Area in British Columbia (BC) between April and November 2021. Demographic characteristics and vaccine attitudes measured by the Vaccine Attitudes Examination (VAX) scale were collected. Each item is scored on a 6-point Likert scale, and higher scores reflect greater hesitancy. A multivariable linear mixed effects model was used to identify sociodemographic factors associated with vaccine hesitancy, adjusting for multiple covariates. RESULTS: A total of 1496 self-identified South Asians (52% female) were analyzed (mean age = 38.5 years; standard deviation (SD): 15.3). The mean VAX score was 3.2, SD: 0.8 [range: 1.0‒6.0]. Factors associated with vaccine hesitancy included: time since immigration (p = 0.04), previous COVID-19 infection (p < 0.001), marital status (p < 0.001), living in a multigenerational household (p = 0.03), age (p = 0.02), education (p < 0.001), and employment status (p = 0.001). CONCLUSION: Among South Asians living in ON and BC, time since immigration, prior COVID-19 infection, marital status, living in a multigenerational household, age, education, and employment status were associated with vaccine hesitancy. This information can be used to address vaccine hesitancy in the South Asian population in future COVID-19 waves or pandemics.

RéSUMé: OBJECTIF: Les Asiatiques du Sud, qui représentent le plus grand groupe ethnique non-blanc au Canada, ont été démesurément touchés par la pandémie de COVID-19. Nous avons cherché à déterminer les facteurs associés à l'hésitation vaccinale chez les Canadiennes et les Canadiens asiatiques du Sud. MéTHODE: Nous avons mené une analyse transversale de l'hésitation vaccinale à l'aide des données collectées durant l'évaluation préliminaire d'une étude de cohorte prospective du nom de COVID CommUNITY South Asian. Les personnes participantes (18 ans et plus) ont été recrutées dans la région du grand Toronto et de Hamilton, en Ontario, et dans la région du Grand Vancouver, en Colombie-Britannique, entre avril et novembre 2021. Le profil démographique et les attitudes face aux vaccins, mesurées selon l'échelle Vaccine Attitudes Examination (VAX), ont été obtenus. Chaque élément a été noté selon une échelle de Likert en 6 points (plus la note est élevée, plus l'hésitation vaccinale est importante). Un modèle linéaire multivarié à effets mixtes a servi à identifier les facteurs sociodémographiques associés à l'hésitation vaccinale, en rajustant les données pour tenir compte de plusieurs covariables. RéSULTATS: En tout, 1 496 personnes s'identifiant comme étant Asiatiques du Sud (dont 52 % de femmes) ont été analysées (âge moyen = 38,5 ans; écart-type [S] : 15,3). La note VAX moyenne était de 3,2, S : 0,8 [intervalle : 1,0‒6,0]. Les facteurs associés à l'hésitation vaccinale étaient : le temps écoulé depuis l'immigration (p = 0,04), une infection antérieure par la COVID-19 (p < 0,001), l'état matrimonial (p < 0,001), le fait de vivre dans un ménage multigénérationnel (p = 0,03), l'âge (p = 0,02), l'instruction (p < 0,001) et la situation d'emploi (p = 0,001). CONCLUSION: Chez les Asiatiques du Sud vivant en Ontario et en Colombie-Britannique, le temps écoulé depuis l'immigration, une infection antérieure par la COVID-19, l'état matrimonial, le fait de vivre dans un ménage multigénérationnel, l'âge, l'instruction et la situation d'emploi étaient associés à l'hésitation vaccinale. Ces informations peuvent être utilisées pour aborder l'hésitation vaccinale dans la population asiatique du Sud lors de vagues de COVID-19 ou de pandémies futures.