Humoral immunogenicity of the seasonal influenza vaccine before and after CAR-T-cell therapy: a prospective observational study.

Recipients of chimeric antigen receptor-modified T (CAR-T) cell therapies for B cell malignancies have profound and prolonged immunodeficiencies and are at risk for serious infections, including respiratory virus infections. Vaccination may be important for infection prevention, but there are limited data on vaccine immunogenicity in this population. We conducted a prospective observational study of the humoral immunogenicity of commercially available 2019-2020 inactivated influenza vaccines in adults immediately prior to or while in durable remission after CD19-, CD20-, or B cell maturation antigen-targeted CAR-T-cell therapy, as well as controls. We tested for antibodies to all four vaccine strains using neutralization and hemagglutination inhibition (HAI) assays. Antibody responses were defined as at least fourfold titer increases from baseline. Seroprotection was defined as a HAI titer ≥40. Enrolled CAR-T-cell recipients were vaccinated 14-29 days prior to (n=5) or 13-57 months following therapy (n=13), and the majority had hypogammaglobulinemia and cellular immunodeficiencies prevaccination. Eight non-immunocompromised adults served as controls. Antibody responses to ≥1 vaccine strain occurred in 2 (40%) individuals before CAR-T-cell therapy and in 4 (31%) individuals vaccinated after CAR-T-cell therapy. An additional 1 (20%) and 6 (46%) individuals had at least twofold increases, respectively. One individual vaccinated prior to CAR-T-cell therapy maintained a response for >3 months following therapy. Across all tested vaccine strains, seroprotection was less frequent in CAR-T-cell recipients than in controls. There was evidence of immunogenicity even among individuals with low immunoglobulin, CD19+ B cell, and CD4+ T-cell counts. These data support consideration for vaccination before and after CAR-T-cell therapy for influenza and other relevant pathogens such as SARS-CoV-2, irrespective of hypogammaglobulinemia or B cell aplasia. However, relatively impaired humoral vaccine immunogenicity indicates the need for additional infection-prevention strategies. Larger studies are needed to refine our understanding of potential correlates of vaccine immunogenicity, and durability of immune responses, in CAR-T-cell therapy recipients.

Personalising Outcomes after Child Cardiac Arrest (POCCA): design and recruitment challenges of a multicentre, observational study.

INTRODUCTION: Blood and imaging biomarkers show promise in prognosticating outcomes after paediatric cardiac arrest in pilot studies. We describe the methods and early recruitment challenges and solutions for an ongoing multicentre (n=14) observational trial, Personalising Outcomes following Child Cardiac Arrest to validate clinical, blood and imaging biomarkers individually and together in a clinically relevant panel. METHODS AND ANALYSIS: Children (n=164) between 48 hours and 17 years of age who receive chest compressions irrespective of provider, duration, or event location and are admitted to an intensive care unit are eligible. Blood samples will be taken on days 1-3 for the measurement of brain-focused biomarkers analysed to predict the outcome. Clinically indicated and timed brain MRI and spectroscopy biomarkers will be analysed to predict the outcome. The primary outcome for the trial is survival with favourable (Vineland Adaptive Behavioural Scale score >70) outcome at 1 year. Secondary outcomes include mortality and pre-event and postdischarge measures of emotional, cognitive, physical and family functioning and health-related quality of life. Early enrollment targets were not met due to prolonged regulatory and subcontract processes. Multiple, simultaneous interventions including modification to inclusion criteria, additional sites and site visits were implemented with successful improvement in recruitment. Study procedures including outcomes and biomarker analysis are ongoing. ETHICS AND DISSEMINATION: Twelve of 14 sites will use the centralised Institutional Review Board (IRB) at the University of Pittsburgh (PRO14030712). Two sites will use individual IRBs: Children's Healthcare of Atlanta Institutional Review Board and Children's Hospital of Wisconsin IRB. Parents and/or guardians are consented and children assented (when possible) by the site Primary investigator (PI) or research coordinator for enrollment. Study findings will be disseminated through scientific conferences, peer-reviewed journal publications, public study website materials and invited lectures. TRIAL REGISTRATION NUMBER: NCT02769026.