新型冠状病毒疫苗接种对成都市境外输入病例流行病学及临床特征的影响分析

目的:分析新型冠状病毒（新冠病毒）疫苗接种对成都市境外输入病例流行病学及临床特征的影响，为新型冠状病毒肺炎疫情防控提供参考依据。方法:截至2021年4月15日，经成都市入境的新冠病毒感染病例，根据新冠病毒疫苗接种史被分为疫苗接种组和疫苗未接种组。回顾性收集和分析病例的流行病学及临床特征资料。实验室检测项目包括新冠病毒核...

Influence of SARS-CoV-2 vaccination on the epidemiological and clinical characteristics of imported COVID-19 cases in Chengdu

Objective To analyze the epidemiological and clinical characteristics of imported COVID-19 cases after SARS-CoV-2 vaccination and to provide evidence for the prevention and control of COVID-19. Methods The imported COVID-19 cases in Chengdu as of April 15, 2021 were divided into the vaccinated group and unvaccinated group according to the history of SARS-CoV-2 vaccination. The epidemiological and clinical data of the cases were collected retrospectively, and the differences in epidemiological and clinical characteristics of the two groups were compared. Laboratory tests consisted of nucleic acid test, clinical index test, serum antibody test and lymphocyte test. Software WPS2019 was used for data management and software R 4.0.3 was used for statistical analysis. Results A total of 75 COVID-19 cases were included in the analysis, in which 20 had received SARS-CoV-2 vaccination and only 4 with clinical symptoms, 55 patients did not receive SARS-CoV-2 vaccination, and 16 had clinical symptoms. In vaccinated group, the first injection time of vaccination ranged from July to November 2020, and 10 cases received two doses of vaccine simultaneously and 10 cases received two doses of vaccine at intervals of 14-57 days. The intervals between the completion of vaccination and the onset ranged from 87 days to 224 days. The differences in classification and clinical type between the two groups were significant. Significant differences were observed in case classification and clinical type between vaccinated group and unvaccinated group (P<0.05). The vaccinated group had a relatively high proportion of asymptomatic infections (40.00%, 8/20), while mild infections were mainly observed in the unvaccinated group(76.36%,42/55). The differences in Ct values (ORF1ab gene and N gene) at the diagnosis were not significant between vaccinated group and unvaccinated group (P>0.05), similar results were also observed in lymphocyte subtypes, procalcitonin and C-reactive protein level comparisons. Serum amyloid A level was higher in unvaccinated group than in vaccinated group (P<0.05). However, the SARS-CoV-2 related serum antibody of IgM, IgG and total antibody levels were significantly higher in vaccinated group (P<0.05). Conclusions Risk of infection still exists with SARS-CoV-2 after vaccination, which can facilitate the production of specific serum antibody of IgM and IgG when people are exposed to the virus. It has a certain protective effect on SARS-CoV-2 infected persons. Vaccination can reduce the clinical symptoms and mitigate disease severity.