Strength Of Response Research Articles

The physiological landscape and specificity of antibody repertoires are consolidated by multiple immunizations.

Diverse antibody repertoires spanning multiple lymphoid organs (i.e., bone marrow, spleen, lymph nodes) form the foundation of protective humoral immunity. Changes in their composition across lymphoid organs are a consequence of B-cell selection and migration events leading to a highly dynamic and unique physiological landscape of antibody repertoires upon antigenic challenge (e.g., vaccination). However, to what extent B cells encoding identical or similar antibody sequences (clones) are distributed across multiple lymphoid organs and how this is shaped by the strength of a humoral response remains largely unexplored. Here, we performed an in-depth systems analysis of antibody repertoires across multiple distinct lymphoid organs of immunized mice and discovered that organ-specific antibody repertoire features (i.e., germline V-gene usage and clonal expansion profiles) equilibrated upon a strong humoral response (multiple immunizations and high serum titers). This resulted in a surprisingly high degree of repertoire consolidation, characterized by highly connected and overlapping B-cell clones across multiple lymphoid organs. Finally, we revealed distinct physiological axes indicating clonal migrations and showed that antibody repertoire consolidation directly correlated with antigen specificity. Our study uncovered how a strong humoral response resulted in a more uniform but redundant physiological landscape of antibody repertoires, indicating that increases in antibody serum titers were a result of synergistic contributions from antigen-specific B-cell clones distributed across multiple lymphoid organs. Our findings provide valuable insights for the assessment and design of vaccine strategies.

Potential of ultrasound stimulation and sonogenetics in vision restoration: a narrative review.

Vision restoration presents a considerable challenge in the realm of regenerative medicine, while recent progress in ultrasound stimulation has displayed potential as a non-invasive therapeutic approach. This narrative review offers a comprehensive overview of current research on ultrasound-stimulated neuromodulation, emphasizing its potential as a treatment modality for various nerve injuries. By examining of the efficacy of different types of ultrasound stimulation in modulating peripheral and optic nerves, we can delve into their underlying molecular mechanisms. Furthermore, the review underscores the potential of sonogenetics in vision restoration, which involves leveraging pharmacological and genetic manipulations to inhibit or enhance the expression of related mechanosensitive channels, thereby modulating the strength of the ultrasound response. We also address how methods such as viral transcription can be utilized to render specific neurons or organs highly responsive to ultrasound, leading to significantly improved therapeutic outcomes.

Vibration response analysis of hydraulic pipeline based on finite element method

The oil pipeline is a critical component that influences the vibration and noise levels of the hydraulic system. Inadequate design may result in resonance or leakage issues, rendering it susceptible to external vibration excitation. To enhance the reliability of the hydraulic pipeline, simulations and analyses were conducted on its modal, harmonic response, and fatigue characteristics. Based on the results of harmonic response analysis and strength analysis, an effective reinforcement scheme was proposed and validated. By inputting the acceleration load to the pipeline system for frequency response analysis, the influence of different excitation forces on the pipeline stress can be determined. The findings indicate that pipeline vibration primarily occurs in the outlet pipe of the transmission, with significant stress and vibration displacement observed at the thermostat valve support. Following structural improvements, there was a notable reduction in stress levels at the transmission outlet pipe, along with a shift in maximum stress position due to additional support. This enhancement has improved both structural stiffness of the outlet pipe and overall stability of the pipeline system.

The pivotal role of the Hes1/Piezo1 pathway in the pathophysiology of glucocorticoid-induced osteoporosis.

Glucocorticoid-induced osteoporosis (GIOP) lacks fully effective treatments. This study investigated the role of Piezo1, a mechanosensitive ion channel component 1, in GIOP. We found reduced Piezo1 expression in cortical bone osteocytes from patients with GIOP and a GIOP mouse model. Yoda1, a Piezo1 agonist, enhanced the mechanical stress response and bone mass and strength, which were diminished by dexamethasone (DEX) administration in GIOP mice. RNA-seq revealed that Yoda1 elevated Piezo1 expression by activating the key transcription factor Hes1, followed by enhanced CaM kinase II and Akt phosphorylation in osteocytes. This improved the lacuno-canalicular network and reduced sclerostin production and the receptor activator of NF-κB/osteoprotegerin ratio, which were mitigated by DEX. Comparative analysis of mouse models and human GIOP cortical bone revealed downregulation of mechanostimulated osteogenic factors, such as osteocrin, and cartilage differentiation markers in osteoprogenitor cells. In human periosteum-derived cells, DEX suppressed differentiation into osteoblasts, but Yoda1 rescued this effect. Our findings suggest that reduced Piezo1 expression and activity in osteocytes and periosteal cells contribute to GIOP, and Yoda1 may offer a novel therapeutic approach by restoring mechanosensitivity.

Functional ultrasound and brain connectivity reveal central nervous system compromise in Trembler-J mice model of Charcot-Marie-Tooth disease

The Charcot-Marie-Tooth-1E (CMT1E) disease is typically described as a peripheral neuropathy in humans, causing decreased nerve conduction, spastic paralysis, and tremor. The Trembler-J (TrJ) mice serve as a high fidelity model of this disease. Here, we use functional ultrasound (fUS) and functional connectivity (FC) to analyze TrJ mice’s brain activity during sensory stimulation and resting state experiments against wild type (WT) mice - the healthy counterpart. fUS is an imaging technique that measures cerebral blood volume (CBV) temporal changes. We study these changes in the primary somatosensory cortex barrel field (S1BF) of both mice populations during periodic vibrissae stimulation, measuring the number of pixels that correlate to the stimulation (i.e., the size of the activation area), the average correlation of these pixels (i.e., the response strength), and the CBV’s rate of change for each stimulation (i.e., the hemodynamic response). Then, we construct a FC matrix for each genotype and experiment by correlating the CBV signals from the eight cortical regions defined by the Paxinos and Franklin atlas. Our results show that TrJ mice have significantly diminished neurovascular responses and altered brain connectivity with respect to WT mice, pointing to central nervous system effects that could shift our understanding of the CMT1E disease.

Hybrid dynamically cross-linked polyurethanes with room temperature self-healing ability for light-responsive actuator

Light-responsive actuators (LRAs) with cross-linked networks that demonstrate fast response and super mechanical strength are essential for practical applications. However, the permanent cross-linked structure typically stabilizes polymer networks and makes them difficult to reprogram or self-heal. Herein, a novel crosslinked light-responsive polyurethane actuator (CPU-DA1SS2) with room temperature self-healing properties was prepared by constructing a hybrid physical and chemical cross-linked polymer network via dynamic DA bonds, SS bonds, and hydrogen bonds. The CPU-DA1SS2 light-responsive actuator exhibits high tensile strength (25.52 MPa) and excellent self-healing efficiency (90.16 %) at room temperature. Moreover, the hybrid dynamic cross-linked network endows the LRAs with liquid-state remold ability and solid-state plasticity, which further contributes to diverse 3D geometric shape remolding. Such a hybrid, dynamic, cross-linked strategy could be utilized to design smart materials that are self-healing and recyclable without sacrificing their mechanical properties, helping to broaden the application areas of LRA materials.

Government response, individual decision-making, and disease spreading: Insights from a game-epidemic dynamics model

During pandemic events, prompt government responses play an indispensable role in controlling the infection situation. Individual decision-making about whether to support government control is crucial for the thorough and effective implementation of policies. To characterise this mechanism, we construct a networked SIR model that introduces an evolutionary game framework. Behavioural effects that significantly influence disease dynamics within the coupled disease-behaviour system are captured through sensitivity analysis. Our results show that the heterogeneity of individual contact is also strongly reflected in their decision-making mechanisms. Groups with larger degrees are more sensitive to changes in the government response strength, while conversely, those with smaller degrees are more likely to be affected by the ratio between the costs of the two strategies. Irrational decision-making by individuals is identified as a central driver in inducing the recurrence of multiple waves of outbreaks. In addition, taking the social dilemma phenomenon as an entry point, we prove from a game-theoretic perspective that individuals with greater degrees in heterogeneous populations have more possibility for interest conflicts with the government and are potential crisis makers during an epidemic. The interaction between government response, individual decision-making, and disease transmission is more comprehensively revealed through our study. Our results are expected to provide theoretical support for public health policymaking in the future.

Investigating the Role of B Cell Receptors in Pathogen Recognition and Immune Response Activation: Implications for Infection Control and Therapeutic Development

Investigating the Role of B Cell Receptors in Pathogen Recognition and Immune Response Activation: Implications for Infection Control and Therapeutic Development

A two-step dynamic FEM-FELA approach for seismic slope stability assessment

AbstractThe determination of the factor of safety (FoS) of slopes during seismic excitation can be complex if the relevant effects of pore water pressure accumulation, nonlinear material response and variable shear strength are duly accounted for. A rational two-step approach to tackle this task based on a hydro-mechanically coupled dynamic simulation and finite element limit analyses is henceforth introduced. To ensure accurate transfer of the hydro-mechanical soil state, a mapping concept is presented, accounting for spatial distributions of stresses, excess pore water pressures, inertial forces and shear strength. The proposed approach is compared to limit equilibrium method (LEM) for the case of a large-scale water-saturated open cast mine slope subjected to seismic loading. In comparison with LEM, the new approach to assess seismic slope stability proves to be simpler in its implementation and straightforward, which could be an important asset for practitioners.

Simplified Gravity Load Collapse Dynamic Analysis of Old-Type Reinforced Concrete Frames

The results of shaking table tests from previous studies on a one-story, two-bay reinforced concrete frame—exhibiting both shear and axial failures—were compared with nonlinear dynamic analyses using simplified models intended to evaluate the collapse potential of older reinforced concrete structures. To replicate the nonlinear behavior of columns, whether shear-critical or primarily flexure-dominant, a one-component beam model was applied. This model features a linear elastic element connected in series to a rigid plastic, linearly hardening spring at each end, representing a concentrated plasticity component. To account for strength degradation through path-dependent plasticity, a negative slope model as degradation was implemented, linking points at both shear and axial failure. The shear failure points were determined through pushover analysis of shear-critical columns using Phaethon software. Although the simplified model provided a reasonable approximation of the overall frame response and lateral strength degradation, especially in terms of drift, its reduced computational demands led to some discrepancies between the calculated and measured shear forces and drifts during certain segments of the time-history response.

Effects of foundation conditions on failure modes of jacket type offshore platforms using incremental irregular wave dynamic analysis

Quantitative assessment of environmental conditions and their loading effects is crucial for the optimal design of marine structures, especially offshore platforms subject to extreme environmental conditions. Wave load, particularly irregular wave load, significantly influences the structural response and ultimate strength of jacket-type offshore platforms (JTOPs) throughout their operational life. The dynamic nature of these irregular wave loads necessitates the use of advanced time history analysis to accurately capture their impact. This study aims to enhance the understanding of how foundation conditions impact failure modes and the structural response of JTOPs through an innovative incremental irregular wave dynamic analysis procedure. By focusing on an existing steel jacket-type platform in the Persian Gulf, this research evaluates six models with varying soil profiles and pile conditions to assess their effects on structural performance. The application of incremental irregular wave dynamic analysis provides a more precise and realistic modeling of wave impacts compared to traditional methods. The findings demonstrate that stronger soil profiles and improved pile conditions significantly enhance structural integrity, particularly under extreme loading conditions. Specifically, optimizing pile configurations is critical for enabling the structure to endure larger waves, whereas variations in the yield stress of steel material have a lesser impact on the platform's response. Additionally, the dynamic results are compared with pushover analysis, which serves as a benchmark to evaluate the accuracy and effectiveness of the pushover analysis compared to incremental irregular wave analysis method used in this study.

The critical impact of remote pilot modelling in evaluation of detect-and-avoid systems explained for ACAS Xu

Detect-and-avoid (DAA) systems for remotely piloted aircraft systems (RPAS) can provide remain well clear (RWC) guidance as well as shorter term resolution advisories (RAs) for collision avoidance, which are both provided in the vertical and horizontal planes. Simulation-based studies for large sets of encounter scenarios are used in the development and evaluation of DAA systems, which encompass safety and operational acceptability of the DAA supported operations. Given the key role of the remote pilot (RP) in responding to RWC guidance and RAs, a RP model is an essential element in such simulations. This paper describes the development of a RP model for evaluation of encounter scenarios involving the ACAS Xu DAA system. The model describes RP situation awareness (perception, comprehension, projection) as basis for decision-making, modes for responding to RAs and/or RWC guidance, response delays, response strengths, and the flight control actions. The RP model includes deterministic and stochastic settings. It is integrated in a simulation environment for encounters of manned and/or unmanned aircraft, the involved DAA and airborne collision avoidance systems, the surveillance and communication systems, and the human operators. Simulation results are provided for a set of encounters between pairs of RPAS both having ACAS Xu for various configurations of the RP model, and for cases with and without sensor errors. The results show that there can be large differences between the results of deterministic and Monte Carlo simulations, indicating that limited sensor errors can have a large impact on the nonlinear system dynamics. Furthermore it is shown that deadlock conditions can exist where the RPAS show oscillatory behaviour and do not manage to effectively pass each other, dependent on the encounter geometry and RP model settings. It is advised to perform a broad sensitively study for RP performance and to study extending the scope of DAA systems to include guidance for efficiently returning to mission without triggering new conflicts.

Distinct inhibitory neurons differently shape neuronal codes for sound intensity in the auditory cortex.

Cortical circuits contain multiple types of inhibitory neurons which shape how information is processed within neuronal networks. Here, we asked whether somatostatin-expressing (SST) and vasoactive intestinal peptide-expressing (VIP) inhibitory neurons have distinct effects on population neuronal responses to noise bursts of varying intensities. We optogenetically stimulated SST or VIP neurons while simultaneously measuring the calcium responses of populations of hundreds of neurons in the auditory cortex of male and female awake, head-fixed mice to sounds. Upon SST neuronal activation, noise bursts representations became more discrete for different intensity levels, relying on cell identity rather than strength. By contrast, upon VIP neuronal activation, noise bursts of different intensity level activated overlapping neuronal populations, albeit at different response strengths. At the single-cell level, SST and VIP neuronal activation differentially modulated the response-level curves of monotonic and nonmonotonic neurons. SST neuronal activation effects were consistent with a shift of the neuronal population responses toward a more localist code with different cells responding to sounds of different intensity. By contrast, VIP neuronal activation shifted responses towards a more distributed code, in which sounds of different intensity level are encoded in the relative response of similar populations of cells. These results delineate how distinct inhibitory neurons in the auditory cortex dynamically control cortical population codes. Different inhibitory neuronal populations may be recruited under different behavioral demands, depending on whether categorical or invariant representations are advantageous for the task.Significance Statement Information about sounds is represented in the auditory cortex by neuronal population activity that has a characteristic sparse structure. Cortical neuronal populations comprise multiple types of excitatory and inhibitory neurons. Here, we find that activating different types of inhibitory neurons differentially controls population neuronal representations, with one type of inhibitory neurons increasing the differences in the identity of the cells recruited to represent the different sounds, and another inhibitory neuron type changing the relative activity level of overlapping neuronal populations. Such transformations may be beneficial for different types of auditory behaviors, suggesting that these different types of inhibitory neurons may be recruited under different behavioral constraints in optimizing neuronal representations of sounds.

Effect of myogenic tone on agonist-mediated vasoconstriction in isolated arteries: A computational study

Background and objectiveVasoconstriction of the resistance artery is mainly determined by an integrated action of multiple local stimuli acting on the vascular smooth muscle cells, which include neuronal delivery of α-adrenoceptor agonists and intraluminal pressure. The contractile activity of the arterial wall has been extensively studied ex vivo using isolated arterial preparations and myography techniques. However, agonist-mediated vasoconstriction response is often confounded by local effects of other stimuli (e.g., pressure) and, it remained unclear whether the pressure-induced myogenic response has any implication on the efficacy of agonist-mediated vasoconstriction during blood flow regulation in tissues. A quantitative understanding of the influence of each stimulus is necessary to understand the interaction between multiple regulatory mechanisms, which is required to ensure timely oxygen delivery to meet tissue needs. MethodsWe developed a simple empirical model of isolated vessel vasoreactivity that includes passive vessel wall mechanics and a lumped representation of active smooth muscle activation as a function of agonist concentration and pressure. Pressure myograph data in dog renal arterioles and rat femoral arterioles, isovolumic myograph data in rat femoral arteries, and vasoactive data in rat skeletal muscle arterioles were analyzed using the model. The effect of physiological pressure changes on the sensitivities of vascular segments to adrenergic agonists phenylephrine and norepinephrine was evaluated. ResultsModel-based analysis of isolated vasoreactivity data, obtained due to changes in pressure and vasoconstricting agonists revealed that the strength of myogenic response of a resistance vessel has a strong influence on the sensitivity and dynamics of agonist response. An increase in intraluminal pressure was found to reduce the magnitude of agonist-mediated tone by lowering the sensitivity of the vessel segment to agonist. The passive mechanical properties of arterial wall considearably influence the agonist-mediated contraction in isolated arteries. These results demonstrate how passive vessel wall mechanics may dominate the vasoactive responses of the common myogenic and adrenergic pathways of smooth muscle contraction in blood flow regulation, supporting a long standing notion that there exists segment-specific vasoregulation in microvascular networks of various tissues. ConclusionThe present model provides a simple and powerful tool for quantifying ex vivo vasoreactivity of asolated arteries to qualitatively study the interaction between myogenic and α-adrenergic control of vascular tone in isolated vessels. Analysis of pressure myography data and isovolumic myography data in different sizes of vessels and tissues, in response to norepinephrine and phenylephrine revealed the importance of passive vessel mechanics in arteriolar vasomotion and setting up of basal vasomotor tone at single vessel-level. The present study will be useful to quantify the extent to which myogenic tone may influence agonist-mediated vasoconstriction and agonist effect on pressure-mediated myogenic response in microvascular networks during blood flow regulation in tissues.

Plantar flexor strength and size decrease following single-leg disuse in uninjured adults: A meta-analysis.

Plantar flexors play a pivotal role in human locomotion and balance. Several original research studies and systematic reviews have characterised the impact of single-leg disuse on plantar flexor strength and size. However, no meta-analysis has quantified the effects of single-leg disuse on changes in plantar flexor strength and size in uninjured adults. To quantify changes in plantar flexor strength and size in response to single-leg disuse. Data were extracted from 19 studies captured in our previous systematic review on studies that employed a unilateral lower limb immobilisation model (cast or brace) and were published up to January 30, 2022. Random-effects meta-analyses were performed on original research studies reporting measures of plantar flexor strength (isometric, isokinetic, or repetition maximum) and size (magnetic resonance imaging or computed tomography) in uninjured adults. Single-leg disuse decreased plantar flexor strength (Hedges gav = -0.71 [95% confidence interval: -0.93, -0.48], p < 0.001, 7-28 days, N = 16 studies, n = 121 participants including ≥13 females, ages 19-29) and plantar flexor size (-0.33 [-0.50, -0.15], p < 0.001, 14-35 days, N = 6, n = 49, 10 females, ages 22-27) across all durations of disuse. Single-leg disuse decreases plantar flexor strength and size in uninjured adults. This work adds to recent meta-analytic findings demonstrating the declines in knee extensors strength and size following single-leg disuse. The paucity of female and participants >30 years old in the single-leg disuse literature examining plantar flexors represents a priority of future work.

Soil Moisture Dominates the Land Surface Feedback in the Development of Compound Drought–Heat Extremes in Tropical South America

Abstract Observational evidence has demonstrated that heat extremes consistently coincide with droughts in tropical South America. However, the underlying causes and associated physical mechanisms remain relatively unexplored. In this study, we employ numerical experiments using Community Earth System Model, version 2 (CESM2), with prescribed oceanic forcing to assess how extreme soil temperature and moisture affect subsequent hydrometeorological conditions during the premonsoon season in tropical South America, a season when land can play an important role in regional climate. The results reveal a different diurnal pattern in the strength of the surface air temperature response, with a stronger response at night to soil temperature anomalies and a stronger response at noon to soil moisture anomalies. Elevated initial soil temperature or reduced initial soil moisture tends to yield warmer and drier hydrometeorological conditions and increase the occurrence of both drought and heat extremes, with stronger and longer-lasting responses to soil moisture anomalies (than soil temperature anomalies). The simulated responses to initial soil moisture anomalies alone closely resemble those in the experiment with combined soil temperature and moisture anomalies. These findings underscore the dominant role of soil moisture feedback in shaping compound drought–heat extremes, in regions where evaporation plays a significant role, highlighting its importance in the modeling and prediction of hydrometeorological extremes.

Prey responses to direct and indirect predation risk cues reveal the importance of multiple information sources.

Prey can use several information sources (cues) to assess predation risk and avoid predation with a variety of behavioural responses (e.g., changes in activity, foraging, vigilance, social behaviour, space use, and reproductive behaviour). Direct cues produced by predators and indirect cues from environmental features or conspecific and heterospecific prey generally provide different types of information about predation risk. Despite widespread interest in understanding behavioural antipredator responses to direct and indirect cues, a clear general pattern of relative response strength across taxa and environments has yet to emerge. We conducted a meta-analysis of studies (N = 113 articles and 999 effect sizes taken from a search of over 7500 articles) testing behavioural responses to direct and indirect cues of predation risk, and their combination, across terrestrial and aquatic ecosystems. We further contrasted if effects were moderated by ecosystem type (terrestrial, marine, or freshwater), cue source (predator, conspecific, heterospecific, or environmental feature), or sensory modality (visual, auditory, or chemosensory). Overall, there were strong effects of risk cues on prey behaviour. We found that prey responded more strongly when both types of cues were presented together compared with either cue in isolation, which was driven by changes in prey activity levels but not other behaviours. There was no general pattern in response strength to direct compared with indirect cues. Responses to these cues were moderated by interactions between environment, cue source, and cue sensory modality (e.g., visual cues elicited stronger responses than other modalities, and responses to conspecific chemosensory cues were stronger than those to predator chemosensory cues in aquatic systems). These results suggest that rather than a broad framework of direct and indirect cues, the specific context of the system should be considered in tests and predictions of how prey respond to risk to elucidate general patterns of antipredator responses.

Determination and analysis of spectral fluorescence cross-sections of bacteria aerosols

Fluorescence cross-sections of single bacteria provide information on the strength of fluorescence response of bacteria for particular excitation conditions and give hints about a possible distinguishability of bacteria by fluorescence techniques. In this report, the fluorescence cross-sections of dry bacteria aerosols are derived from fluorescence spectra by absolute calibration of the measuring system. The fluorescence is measured in a continuous aerosol flow. The aerosol concentration is calculated from microscopic analyses of bacteria samples taken from the aerosol flow. Established calibration methods such as Mie scattering from monodisperse spheres and Raman scattering from water are applied to the same set of fluorescence spectra. The cross-section data obtained are evaluated with regard to their independency from the applied measuring system. The results are compared to data published in the literature. Polarization effects are identified to contribute to the discrepancies between the different datasets.Graphical abstract

Tunable enhanced chiroptical response of a twisted L-shaped plasmon nanoparticle system

Chiroptical responses in plasmon systems have aroused widespread interest, manifesting potential application in fields including physics, biology, and pharmacy, as well as other disciplines. However, the enhancement and tunability of chiroptical responses by strong plasmon coupling, which have been seldom discussed, remain wanting. In this paper, we propose a stacked and twisted L-shaped nanoparticle system, which exhibits an enhanced chiroptical response and the dynamic modulation of chiroptical response. By adjusting the twist angle and the gap between L-shaped nanoparticles, the anisotropy factor g, which quantifies the relative strength of the chiroptical response, can reach up to −1.5, and the peak position and linewidth of the g spectrum can be modified. Furthermore, in instances where the chiroptical response is weak, we construct a finite-size 1D chain by using the proposed system as the unit cell. By harnessing the global interaction among the unit cell of the 1D chain, the maximum value of g can be effectively improved and adjusted. Such an L-shaped nanoparticle system as a fundamental structure has potential applications in tunable chiroptical devices and also extends methods for device design.

Antibody levels versus vaccination status in the outcome of older adults with COVID-19.

BACKGROUNDDespite the currently prevailing, milder Omicron variant of COVID-19, older adults remain at elevated risk of hospital admission, critical illness, and death. Loss of efficacy of the immune system, including reduced strength, quality, and durability of antibody responses, may render generalized recommendations on booster vaccinations inadequate. There is a lack of data on the efficacy of antibody levels in older adults and on the utility of vaccination status versus antibody levels as a correlate of protection. It is further unclear whether antibody levels may be used to guide the timing of booster vaccinations in older adults.METHODSWe conducted a prospective multicenter cohort study comprising hospitalized patients with COVID-19. Anti-SARS-CoV-2 spike antibodies were measured on hospital admission. The primary endpoint was in-hospital mortality. Patients were stratified by age, antibody levels, and vaccination status. Multiple logistic regression and Cox regression analyses were conducted.RESULTSIn total, 785 older patients (≥60 years of age [a]) and 367 controls (<60a) were included. After adjusting for confounders, risk of mortality, ICU admission, endotracheal intubation, and oxygen administration was 4.9, 2.6, 6.5, and 2.3 times higher, respectively, if antibody levels were < 1,200 BAU/mL (aOR, 4.92 [95%CI, 2.59-9.34], P < 0.0001; aOR, 2.64 [95%CI, 1.52-4.62], P = 0.0006; aOR, 6.50 [95%CI, 1.48-28.47], P = 0.013; aOR, 2.34 [95%CI, 1.60-3.343], P < 0.0001). Older adults infected with the Omicron variant were approximately 6 times more likely to die if antibody levels were < 1,200 BAU/mL (aOR, 6.3 [95% CI, 2.43-16.40], P = 0.0002).CONCLUSIONAntibody levels were a stronger predictor of in-hospital mortality than vaccination status. Monitoring antibody levels may constitute a better and more direct approach for safeguarding older adults from adverse COVID-19 outcomes.