The evaluation of the immune status of COVID-19 recovered subjects with persistent abnormal lung CT after one year: A longitudinal cohort study

•Longitudinal observation of the dynamic changes of 4 categories and 23 immune indicators of COVID-19 recovered subjects within one year.•Patients with older age, higher BMI, severe disease, and underlying diseases (hypertension, diabetes) have a higher rate of CT abnormalities.•High levels of complement C3 were associated with persistent lung abnormalities in COVID-19 recovered subjects.