ABSTRACT
BackgroundImmunizations among vulnerable population, including solid organ transplant recipients (SOT), present suboptimal responses at vaccination and over time. We investigated safety and immunogenicity of the BNT162B2 mRNA COVID-19 vaccine in 34 SOT young adults as compared to 36 healthy controls (HC). Methodsimmunogenicity was measured through the analysis of anti SARS-CoV2 IgG Antibodies and antigen specific CD4 T cells (CD40L+), detected by flow cytometry before vaccination, 21 days after priming (T21), 7 days after booster dose (T28) and 2-4 months after priming (T120). Baseline T and B cell immune phenotype was deeply investigated. The safety profile was investigated by close monitoring and self-reported diary. ResultsAnti-S and anti-Trimeric Ab responses were significantly lower in SOT vs HC at T21 (p<0.0001) and at T28 (p<0.0001). Ten out of 34 SOT (29%) at T28 and 3 out of 33 (9%) at T120 had undetectable SARS-CoV-2 IgG. The analysis of SARS-CoV-2 specific CD4 T cells showed lower CD40L expression after in vitro stimulation in SOT compared to HC. Lower frequencies of memory B cells were found in patients not responding to vaccination. Lack of seroconversion was higher in patients treated with mycophenolate (p=0.0005). The vaccination was safe and well tolerated. Only short-term adverse events, were reported and no hospitalization or graft rejection were observed after vaccinations. ConclusionsThese data show that SOT have a suboptimal immune response following mRNA vaccinations as compared to HC. Alternative strategies should be investigated to improve the immunization against SARS-CoV-2 in these patients.
ABSTRACT
SARS-CoV-2 infection is typically very mild and often asymptomatic in children. A complication is the rare Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19, presenting 4-6 weeks after infection as high fever, organ dysfunction and strongly elevated markers of inflammation. The pathogenesis is unclear but has overlapping features with Kawasaki disease suggestive of vasculitis and a likely autoimmune etiology. We apply systems-level analyses of blood immune cells, cytokines and autoantibodies in healthy children, children with Kawasaki disease enrolled prior to COVID-19, children infected with SARS-CoV-2 and children presenting with MIS-C. We find that the inflammatory response in MIS-C differs from the cytokine storm of severe acute COVID-19, shares several features with Kawasaki disease, but also differs from this condition with respect to T-cell subsets, IL-17A and biomarkers associated with arterial damage. Finally, autoantibody profiling suggests multiple autoantibodies that could be involved in the pathogenesis of MIS-C. HIGHLIGHTSHyperinflammation in MIS-C differs from that of acute COVID-19 T-cell subsets discriminate Kawasaki disease patients from MIS-C IL-17A drives Kawasaki, but not MIS-C hyperinflammation. Global autoantibodies profiling indicate possibly pathogenic autoantibodies
