Abstract:Objective To compare clinical characteristics of imported coronavirus disease 2019 (COVID-19) patients after inoculated/non-inoculated inactivated vaccine (Vero cells) for SARS-CoV-2, provide reference for clinical diagnosis and treatment. Methods Imported COVID-19 patients who had inoculated inactivated vaccine (vaccinated group) and COVID-19 patients from the same countries but didn't inoculate vaccine (non-vaccinated group) who were admitted in Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 4 to April 10, 2021 were chosen. Through comparing the demographic characteristics, clinical symptoms, blood test results and antibodies, chest imaging, as well as treatment methods and prognosis of two groups of patients, clinical chara-cteristics of imported COVID-19 patients after inoculated inactivated vaccine were analyzed and summarized. Results 38 patients in vaccinated group and 38 in non-vaccinated group were included in analysis, the average age of patients was (37.14±8.86) and (39.21±7.66) years old respectively; 58 were males and 18 were females. In the clinical symptoms of two groups, except throat discomfort rate of non-vaccinated group was higher than that of vaccinated group (34.21% vs 13.16%, P < 0.05), there was no significant difference in other clinical symptoms between two groups (P>0.05). There were no significant differences in white blood cells, lymphocytes, liver and kidney function, myocardial enzyme, oxygenation index and D-2 polymer between two groups of patients (P>0.05); there were also no significant differences in the increased proportion of inflammation markers as well as decreased proportion of T lymphocytes CD4+ and CD8+ between two groups of patients (P>0.05). Within 2 weeks before disease course, positive rate of SARS-CoV-2 antibody IgG in vaccinated group was higher than that in non-vaccinated group, difference was statistically significant (P < 0.05). There was no significant difference in lung imaging between two groups of patients (P>0.05). Conclusion Imported COVID-19 patients after inoculating inactivated vaccine (Vero cells) are mainly young and middle-aged men, most clinical types are nucleic acid test positive and common type, all patients had a good prognosis after treatment. Compared with patients without inoculating inactivated vaccine, patients infected SARS-CoV-2 after inoculating vaccine can produce IgG antibody rapidly in the early stage of disease (within one week), but nucleic acid turns negative for a long time.