To better understand primary and recall T cell responses during COVID-19, it is important to examine unmanipulated SARS-CoV-2-specific T cells. Using peptide-HLA tetramers for direct ex vivo analysis, we characterized CD8 + T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8 + T cells directed towards subdominant epitopes – B7/N 257 , A2/S 269 and A24/S 1208 – CD8 + T cells specific for the immunodominant B7/N 105 epitope were detected at high frequency in pre-pandemic samples, and at increased frequency during acute COVID-19 and convalescence. SARS-CoV-2-specific CD8 + T cells in pre-pandemic samples from children, adults and elderly individuals predominantly displayed a naïve phenotype, indicating a lack of previous cross-reactive exposures. T cell receptor (TCR) analyses revealed diverse TCRαβ repertoires and promiscuous αβ-TCR pairing within B7/N 105 + CD8 + T cells. Our study demonstrates high naive precursor frequency and TCRαβ diversity within immunodominant B7/N 105 -specific CD8 + T cells, and provides insight into SARS-CoV-2-specific T cell origins and subsequent responses.

There is growing interest in the area of elite athlete mental health, however brief, valid and reliable screening instruments designed to identify early indictors of athlete-specific distress and potential mental health symptoms are lacking. This study sought to develop a brief screening instrument for athlete populationsthe Athlete Psychological Strain Questionnaire (APSQ)and examine convergent, divergent and construct validity. A twostage psychometric validation study was undertaken. Self-report data was collected from 1,007 currently competing Australian elite male athletes (M = 23.67, SD = 4.16). The sample was randomly partitioned into calibration (n = 497) and validation (n = 510) samples. Exploratory and confirmatory factor analysis, and tests of differential item functioning were conducted. Exploratory factor analysis, with parallel analysis, conducted on the calibration sample supported a three-factor solution, with subscales assessing Self-Regulation, Performance and External Coping accounting for 50.44% of total scale variance. Confirmatory factor analysis supported this three-factor model, yielding excellent model fit indices (CFI = 0.976, TLI = 0.966, RMSEA = 0.055, SRMR = 0.032), with the Bayesian Information Criterion supporting the superordinate structure. Differential item functioning analysis indicated item-equivalence relative to athletes' level of education and ethnicity. As predicted, a multivariate effect indicated higher APSQ scores for currently injured athletes (p = .040) with a univariate effect on the Performance subscale. The APSQ may help identify early symptoms of athlete psychological strain facilitating timely management. Replication and validation studies in broader samples, including female athletes and comparison with other athlete-specific, coping and stress measures are needed.

The 2017 Berlin Concussion in Sport Group Consensus Statement provides a global summary of best practice in concussion prevention, diagnosis and management, underpinned by systematic reviews and expert consensus. Due to their different settings and rules, individual sports need to adapt concussion guidelines according to their specific regulatory environment. At the same time, consistent application of the Berlin Consensus Statement’s themes across sporting codes is likely to facilitate superior and uniform diagnosis and management, improve concussion education and highlight collaborative research opportunities. This document summarises the approaches discussed by medical representatives from the governing bodies of 10 different contact and collision sports in Dublin, Ireland in July 2017. Those sports are: American football, Australian football, basketball, cricket, equestrian sports, football/soccer, ice hockey, rugby league, rugby union and skiing. This document had been endorsed by 11 sport governing bodies/national federations at the time of being published.

BackgroundThe use of video to assist professional sporting bodies with the diagnosis of sport-related concussion (SRC) has been well established; however, there has been little consistency across sporting codes with regards to which video signs should be used, and the definitions of each of these signs.AimThe aims of this study were to develop a consensus for the video signs considered to be most useful in the identification of a possible SRC and to develop a consensus definition for each of these video signs across the sporting codes.MethodsA brief questionnaire was used to assess which video signs were considered to be most useful in the identification of a possible concussion. Consensus was defined as >90% agreement by respondents. Existing definitions of these video signs from individual sports were collated, and individual components of the definitions were assessed and ranked. A modified Delphi approach was then used to create a consensus definition for each of the video signs.ResultsRespondents representing seven sporting bodies (Australian Football League, Cricket Australia, Major League Baseball, NFL, NHL, National Rugby League, World Rugby) reached consensus on eight video signs of concussion. Thirteen representatives from the seven professional sports ranked the definition components. Consolidation and refinement of the video signs and their definitions resulted in consensus definitions for six video signs of possible concussion: lying motionless, motor incoordination, impact seizure, tonic posturing, no protective action—floppy and blank/vacant look.ConclusionsThese video signs and definitions have reached international consensus, are indicated for use by professional sporting bodies and will form the basis for further collaborative research.