Humoral response dynamics following inactivated SARS-CoV-2 vaccination and their association with subsequent infection and symptoms in individuals with and without prior SARS-CoV-2 infection: evidence from Sichuan Province, China

To better identify vulnerable populations in epidemic surveillance and predict their clinical manifestations post-infection for accurate diagnosis and effective management, it is vital to understand the intrinsic dynamic immune patterns among individuals and how these trajectory patterns relate to future infections and associated symptoms. In the post-COVID-19 era, conducting nuanced analyses remains of great significance, especially as longer-term observational data become available. This is the first finding from China that illustrates the dynamic characteristics of the immune response following inactivated COVID-19 vaccination over an extended observation period, including information on following infection and symptoms. These data are particularly valuable as no participants experienced COVID-19 infection during the vaccine cohort follow-ups, meaning their antibody levels solely reflect the intrinsic dynamic immune patterns triggered by the inactivated COVID-19 vaccines.