Shared Clinical and Immunological Features of Post-Acute COVID-19 and Post-Acute COVID-19 Vaccination Syndromes

The study compared 28 patients with post-acute COVID-19 (PACS), 29 patients with post-acute vaccination syndrome (PACVS), and 16 control subjects. Both patient groups exhibited similar clinical symptoms including fatigue, post-exertional malaise, neurocognitive symptoms, and autonomic manifestations, with some symptoms being more severe in PACS. The research revealed comparable GPCR autoantibody profiles in both patient groups and elevated beta2-adrenergic receptor autoantibodies compared to controls. Circulating Spike protein was detected in both patient groups, with the highest prevalence in PACVS. Both groups showed increased CD4+ T cells reactive to beta1/beta2- and M3/M4-receptors, while Spike-specific CD4+ T cells were reduced. EBV reactivation was rare. The findings suggest shared immunological mechanisms between PACS and PACVS.