Citations

Summary Human spaceflight has historically been led by government agencies, but the emergence of commercial organizations is enabling broader participation and new research opportunities. In this study, we present a comprehensive molecular characterization of early human responses to spaceflight, leveraging multi-omics data across the first three weeks of two commercial missions. Biospecimens from six individuals, four from the Axiom 2 mission (10 days) and two from Axiom 3 (21 days), were analyzed using single-cell and bulk RNA sequencing, alongside proteomic profiling. Individual and integrative analyses of these datasets reveal systemic changes in cell types, transcripts, and proteins related to immune regulation, osteoclast differentiation, NF-κB signaling, and blood homeostasis pathways. Importantly, several of the detected pathways align with physiological patterns observed in longer-duration missions. This work establishes a foundational resource for understanding early adaptation to spaceflight at the cellular and molecular levels, providing insights to reduce future space-travel health risks. Highlights First integrated multi-omics analysis using single-cell, bulk RNA sequencing and proteomic profiling of early human spaceflight responses across two commercial missions (Ax-2 and Ax-3). Distinct PBMC clustering was observed across Ax-2 and Ax-3, and post-flight samples. It showed fewer monocytes, dendritic cells, and megakaryocytes with increased naïve CD4⁺ and cytotoxic T cells. Multi-omics integration identifies shared biological signatures, including osteoclast differentiation, metabolic stress, and coagulation changes. These findings lay the foundation for developing countermeasures to protect immune, skeletal, and vascular health during spaceflight.

SIGNIFICANCE This pilot randomized trial, the first to evaluate a specific base‐in relieving prism treatment strategy for childhood intermittent exotropia, did not support proceeding to a full‐scale clinical trial. Defining and measuring prism adaptation in children with intermittent exotropia are challenging and need further study. PURPOSE This study aimed to determine whether to proceed to a full‐scale trial of relieving base‐in prism spectacles versus refractive correction alone for children with intermittent exotropia. METHODS Children 3 years old to those younger than 13 years with distance intermittent exotropia control score of ≥2 points on the Intermittent Exotropia Office Control Scale (Strabismus 2006;14:147–150; 0 [phoria] to 5 [constant]), ≥1 episode of spontaneous exotropia, and 16 to 35∆ by prism‐and‐alternate‐cover test, who did not fully prism adapt on a 30‐minute in‐office prism‐adaptation test were randomized to base‐in relieving prism (40% of the larger of distance and near exodeviations) or nonprism spectacles for 8 weeks. A priori criteria to conduct a full‐scale trial were defined for the adjusted treatment group difference in mean distance control: “proceed” (≥0.75 points favoring prism), “uncertain” (>0 to <0.75 points favoring prism), or “do not proceed” (≥0 points favoring nonprism). RESULTS Fifty‐seven children (mean age, 6.6 ± 2.2 years; mean baseline distance control, 3.5 points) received prism (n = 28) or nonprism (n = 29) spectacles. At 8 weeks, mean control values were 3.6 and 3.3 points in prism (n = 25) and nonprism (n = 25) groups, respectively, with an adjusted difference of 0.3 points (95% confidence interval, −0.5 to 1.1 points) favoring nonprism (meeting our a priori “do not proceed” criterion). CONCLUSIONS Base‐in prism spectacles, equal to 40% of the larger of the exodeviations at distance or near, worn for 8 weeks by 3‐ to 12‐year‐old children with intermittent exotropia did not yield better distance control than refractive correction alone, with the confidence interval indicating that a favorable effect of 0.75 points or larger is unlikely. There was insufficient evidence to warrant a full‐scale randomized trial.