Abstract The COVID-19pandemic has led to a significant number of individuals experiencing persistentpost-acute sequelae, commonly referred to as long COVID, following SARS-CoV-2infection. Similar symptoms, though less frequent, have also been observed after COVID-19 vaccination. This studyinvestigated the immune and inflammatory profiles of patients with long COVIDsymptoms, focusing on differences between post-infection and post-vaccination cases. A total of 110 patients (61 post-infection and 49 post-vaccination) were assessed at three and six months after symptom onset, alongside 40 controls.Serological testing was performed for SARS-CoV-2-specific antibodies, including neutralizing, non-neutralizing, and anti-ACE2 antibodies, and cytokineprofiling was conducted using a 19-marker panel.Post-infection patients exhibited elevated andincreasing levels of anti-ACE2 antibodies and persistently high levels of pro-inflammatory cytokines such as IL-1β, IFN-γ, and MCP-1, indicating ongoing immune dysregulation and possible autoimmunity. In contrast, post-vaccination patients demonstrated stable antibody levels and cytokine profiles comparableto controls, suggesting a more regulated and transient immune response. These findings highlight the immunological heterogeneity of long COVID and support the need for targeted diagnostic and therapeutic approaches tailored to the underlying immune mechanisms in post-infection and post-vaccination subgroups.
Chanida Ruchisrisarod (Tue,) studied this question.