Objective: To explore the effect of vaccination on viral negative conversion of children with COVID-19. Methods: A retrospective cohort study was conducted. A cohort of 189 children aged 3-14 years with COVID-19 admitted to Renji Hospital (South branch) of Shanghai Jiao Tong University School of Medicine from April 7th to May 19th 2022 was enrolled in the study. According to the vaccination status, the infected children were divided into an unvaccinated group and a vaccinated group. Age, gender, severity, clinical manifestations, and laboratory tests, etc. were compared between groups, by rank sum test or chi-square test. The effects of vaccination on viral negative conversion were analyzed by a Cox mixed-effects regression model. Additionally, a questionnaire survey was conducted among the parents of unvaccinated children to analyze the reasons for not being vaccinated. Results: A total of 189 children aged 3-14 years were enrolled, including 95 males (50.3%) and 94 females (49.7%), aged 5.7 (4.1,8.6) years. There were 117 cases (61.9%) in the unvaccinated group and 72 cases (38.1%) in the vaccinated group. The age of the vaccinated group was higher than that of the unvaccinated group (8.8 (6.8, 10.6) vs. 4.5 (3.6, 5.9) years, Z=9.45, P<0.001). No significant differences were found in clinical manifestations, disease severity, and laboratory results between groups (all P>0.05), except for the occurrence rate of cough symptoms, which was significantly higher in the vaccinated group than in the non-vaccinated group (68.1% (49/72) vs. 50.4% (59/117),χ2=5.67, P=0.017). The Kaplan-Meier survival curve and Cox mixed-effects regression model showed that the time to the viral negative conversion was significantly shorter in the vaccinated group compared with the unvaccinated group (8 (7, 10) vs. 11 (9, 12) d, Z=5.20, P<0.001; adjusted HR=2.19 (95%CI 1.62-2.97)). For questionnaire survey on the reasons for not receiving a vaccination, 115 questionnaires were distributed and 112 valid questionnaires (97.4%) were collected. The main reasons for not being vaccinated were that parents thought that their children were not in the range of appropriate age for vaccination (51 cases, 45.5%) and children were in special physical conditions (47 cases, 42.0%). Conclusion: Vaccination can effectively shorten the negative conversion time of children with COVID-19 and targeted programs should be developed to increase eligible children's vaccination rate for SARS-CoV-2 vaccination.
目的： 探讨新型冠状病毒疫苗接种对新型冠状病毒肺炎（简称新冠肺炎）患儿病毒核酸转阴时间的影响。 方法： 回顾性队列研究。以2022年4月7日至5月19日在上海市新冠肺炎定点收治单位上海交通大学医学院附属仁济医院（南部院区）收治的189例3~14岁新冠肺炎患儿为队列人群，按照疫苗接种情况分为未接种组和接种组，总结分析患儿年龄、性别、分型、临床表现及实验室检查等数据，组间比较采用秩和检验或χ²检验。对疫苗接种情况和病毒核酸转阴时间相关性进行Cox混合效应回归模型分析。并对未接种组患儿家长进行问卷调查，分析患儿未接种疫苗原因。 结果： 189例3~14岁新冠肺炎患儿中男95例（50.3%）、女94例（49.7%），年龄5.7（4.1，8.6）岁。未接种组117例（61.9%）、接种组72例（38.1%）。接种组年龄大于未接种组［8.8（6.8，10.6）比4.5（3.6，5.9）岁，Z=9.45，P<0.001］。临床表现、疾病分型及检验结果组间比较，除咳嗽症状发生率接种组高于未接种组［68.1%（49/72）比50.4%（59/117），χ2=5.67，P=0.017］，其余差异均无统计学意义（均P>0.05）。Kaplan-Meier曲线及Cox混合效应回归模型结果显示接种组病毒核酸转阴时间短于未接种组［8（7，10）比11（9，12）d，Z=5.20，P<0.001；矫正HR=2.19（95%CI 1.62~2.97）］。未接种疫苗原因问卷调查发放115份问卷，收集有效问卷112份（97.4%），其中家长认为患儿不在接种适龄范围（51例，45.5%）及身体特殊情况（47例，42.0%）是未接种疫苗的主要原因。 结论： 接种疫苗可以有效缩短新冠肺炎患儿病毒核酸转阴时间，应积极制定针对性方案，提高新型冠状病毒疫苗适龄儿童接种率。.