27The SARS-CoV-2 pandemic has caused a severe international shortage of the nasopharyngeal 28 swabs that are required for collection of optimal specimens, creating a critical bottleneck 29 blocking clinical laboratories' ability to perform high-sensitivity virological testing for SARS-CoV-30 2. To address this crisis, we designed and executed an innovative, cooperative, rapid-response 31 translational-research program that brought together healthcare workers, manufacturers, and 32 scientists to emergently develop and clinically validate new swabs for immediate mass 33 production by 3D printing. We performed a multi-step preclinical evaluation on 160 swab 34 designs and 48 materials from 24 companies, laboratories, and individuals, and shared results 35 and other feedback via a public data repository (http://github.com/rarnaout/Covidswab/). We 36 validated four prototypes through an institutional review board (IRB)-approved clinical trial that 37 involved 276 outpatient volunteers who presented to our hospital's drive-through testing center 38 with symptoms suspicious for COVID-19. Each participant was swabbed with a reference swab 39 (the control) and a prototype, and SARS-CoV-2 reverse-transcriptase polymerase chain 40 reaction (RT-PCR) results were compared. All prototypes displayed excellent concordance with 41 the control (κ=0.85-0.89). Cycle-threshold (Ct) values were not significantly different between 42 each prototype and the control, supporting the new swabs' non-inferiority (Mann-Whitney U 43[MWU] p>0.05). Study staff preferred one of the prototypes over the others and the control swab 44 overall. The total time elapsed between identification of the problem and validation of the first 45 prototype was 22 days. Contact information for ordering can be found at http://printedswabs.org. 46Our experience holds lessons for the rapid development, validation, and deployment of new 47 technology for this pandemic and beyond. 48 on June 9, 2020 by guest

Background Resolving the coronavirus disease 2019 (COVID-19) pandemic requires diagnostic testing to determine which individuals are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current gold standard is to perform reverse-transcription polymerase chain reaction (PCR) on nasopharyngeal samples. Best-in-class assays demonstrate a limit of detection (LoD) of approximately 100 copies of viral RNA per milliliter of transport media. However, LoDs of currently approved assays vary over 10,000-fold. Assays with higher LoDs will miss infected patients. However, the relative clinical sensitivity of these assays remains unknown. Methods Here we model the clinical sensitivities of assays based on their LoD. Cycle threshold (Ct) values were obtained from 4700 first-time positive patients using the Abbott RealTime SARS-CoV-2 Emergency Use Authorization test. We derived viral loads from Ct based on PCR principles and empiric analysis. A sliding scale relationship for predicting clinical sensitivity was developed from analysis of viral load distribution relative to assay LoD. Results Ct values were reliably repeatable over short time testing windows, providing support for use as a tool to estimate viral load. Viral load was found to be relatively evenly distributed across log10 bins of incremental viral load. Based on these data, each 10-fold increase in LoD is expected to lower assay sensitivity by approximately 13%. Conclusions The assay LoD meaningfully impacts clinical performance of SARS-CoV-2 tests. The highest LoDs on the market will miss a majority of infected patients. Assays should therefore be benchmarked against a universal standard to allow cross-comparison of SARS-CoV-2 detection methods.

Steroid-refractory acute graft-versus-host disease (SR-aGVHD) following hematopoietic cell transplantation (HSCT) is associated with poor clinical outcomes. Currently, there are no safe and effective therapies approved for use in the pediatric population under the age of 12 years. Accordingly, there is an urgent need for new treatments that are safe, well tolerated, and effective in managing this debilitating and potentially fatal complication of HSCT. In early phase clinical trials, mesenchymal stromal cells (MSCs) have demonstrated efficacy in the treatment of acute GVHD (aGVHD) in pediatric patients. We now report the results of a phase 3, prospective, single-arm, multicenter study (NCT02336230) in 54 children with primary SR-aGVHD who were naive to other immunosuppressant therapies for aGVHD treated with MSC product (remestemcel-L) dosed at 2 £ 10 6 cells/kg twice weekly for 4 weeks. Remestemcel-L therapy significantly improved day 28 overall response rate (OR) compared with the prespecified control OR value of 45% (70.4% versus 45%, P = .0003). The statistically significant OR (70.4%) was sustained through day 100, including an increase in complete response from 29.6% at day 28 to 44.4% at day 100. Overall survival was 74.1% at day 100 and 68.5% at day 180. Overall response in all participants at day 28 was highly predictive of improved survival through 180 days, and survival was significantly greater in day 28 responders compared with nonresponders through day 100 (86.8% versus 47.1% for responders and nonresponders, respectively, P = .0001) and through day 180 (78.9% versus 43.8%, P = .003). Remestemcel-L was well tolerated with no identified infusion-related toxicities or other safety concerns. This study provides robust, prospective evidence of the safety, tolerability, and efficacy of remestemcel-L as first-line therapy after initial steroid failure in pediatric SR-aGVHD.

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Several commercial methods exist for the molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae in clinical samples. Here we evaluated the performance characteristics of the newly FDAcleared Abbott RealTime CT/NG assay (where "CT" stands for Chlamydia trachomatis and "NG" stands for Neisseria gonorrhoeae) that uses the automated m2000 molecular platform. Results were compared to those of the Roche Cobas Amplicor CT/NG assay. A total of 926 cervical swab, 45 female urine, 6 male urethral swab, and 407 male urine specimens from 1,384 patients were examined. After resolving all Roche N. gonorrhoeae-positive results with two additional real-time PCR assays, we found that the agreement between the assays was excellent. For urine samples, there was 99.6% positive agreement and 97.7% negative agreement for C. trachomatis, and for male urine samples, there was 100% positive agreement and 99.7% negative agreement for N. gonorrhoeae. For cervical swab samples, there was 98.8% positive agreement and 98.5% negative agreement for C. trachomatis, and there was 96.6% positive agreement and 99.8% negative agreement for N. gonorrhoeae. In limiting dilution analyses, we found that the Abbot assay was more sensitive than the Roche assay for both C. trachomatis and N. gonorrhoeae. In addition, there appeared to be an enhanced ability of the Abbott assay to detect dual infections, especially in the presence of large amounts of N. gonorrhoeae and small amounts of C. trachomatis organisms. In summary, we conclude that the Abbott RealTime CT/NG assay is an accurate and automated new addition to the available testing options for C. trachomatis and N. gonorrhoeae.The incidences of Chlamydia trachomatis and Neisseria gonorrhoeae infection continue to increase globally. A more intensive screening effort has been advocated by the U.S. Preventive Services Task Force (18), the Centers for Disease Control and Prevention (24), other public health agencies, and medical societies to bring this emerging epidemic under control. This includes the yearly screening of sexually active women under the age of 25 years for C. trachomatis. The goal of screening is to prevent transmission and the severe sequelae of unrecognized infection, such as pelvic inflammatory disease and associated infertility.Rapid, automated, and sensitive nucleic acid amplification testing methods are needed to respond optimally to this public health mandate. In this regard, there have been limited published evaluations of the recently FDA-cleared Abbott RealTime CT/NG assay (where "CT" stands for Chlamydia trachomatis and "NG" stands for Neisseria gonorrhoeae) (9). There was a recent report of clinical trial data comparing the Abbott assay to Gen-Probe Aptima Combo 2 (AC2), BD ProbeTec ET CT/GC, and GC culture (where "GC" represents N. gonorrhoeae) (6). There was also one prior study from Canada using a CE-marked Abbott kit with different cutoff and interpretation algorithms (8) and a U.S. study performed by Abbott Laboratories (Des Plaines, IL) using a prototype ...