National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing.
Shanghai Institute of Infectious Disease and Biosecurity, Key Laboratory of Medical Molecular Virology of Ministry of Education and Ministry of Health, and Institutes of Biomedical Sciences, Medical College, Fudan University, Shanghai.
J Infect Dis. 2023 Aug 11;228(3):261-269. doi: 10.1093/infdis/jiad090.
China has been using inactivated coronavirus disease 2019 (COVID-19) vaccines as primary series and booster doses to protect the population from severe to fatal COVID-19. We evaluated primary and booster vaccine effectiveness (VE) against Omicron BA.2 infection outcomes.
This was a 13-province retrospective cohort study of quarantined close contacts of BA.2-infected individuals. Outcomes were BA.2 infection, COVID-19 pneumonia or worse, and severe/critical COVID-19. Absolute VE was estimated by comparison with an unvaccinated group.
There were 289 427 close contacts ≥3 years old exposed to Omicron BA.2 cases; 31 831 turned nucleic acid amplification test-positive during quarantine, 97.2% with mild or asymptomatic infection, 2.6% with COVID-19 pneumonia, and 0.15% with severe/critical COVID-19. None died. Adjusted VE (aVE) against any infection was 17% for primary series and 22% when boosted. Primary series aVE in adults >18 years was 66% against COVID-19 pneumonia or worse and 91% against severe/critical COVID-19. Booster dose aVE was 74% against pneumonia or worse, and 93% against severe/critical COVID-19.
Inactivated COVID-19 vaccines provided modest protection from infection, very good protection against pneumonia, and excellent protection against severe/critical COVID-19. Booster doses are necessary to provide strongest protection.
中国一直使用新冠病毒灭活疫苗作为基础免疫和加强针，以保护人群免受新冠病毒感染导致的重症和死亡。我们评估了针对奥密克戎 BA.2 感染的基础免疫和加强针疫苗的有效性（VE）。
这是一项在 13 个省份进行的、针对 BA.2 感染密切接触者的回顾性队列研究。结局是 BA.2 感染、新冠肺炎或更严重疾病、以及重症/危重症新冠肺炎。通过与未接种疫苗的人群进行比较来估计绝对 VE。
共有 289427 名≥3 岁的密切接触者暴露于奥密克戎 BA.2 病例；在隔离期间，有 31831 人核酸扩增检测呈阳性，97.2%为轻症或无症状感染，2.6%为新冠肺炎肺炎，0.15%为重症/危重症新冠肺炎。无人死亡。基础免疫的调整 VE（aVE）为 17%，加强针为 22%。18 岁及以上成年人基础免疫 aVE 对新冠肺炎肺炎或更严重疾病的保护率为 66%，对重症/危重症新冠肺炎的保护率为 91%。加强针的 aVE 为 74%对肺炎或更严重疾病，93%对重症/危重症新冠肺炎。
新冠病毒灭活疫苗对感染提供了适度的保护，对肺炎提供了很好的保护，对重症/危重症新冠肺炎提供了极好的保护。加强针是提供最强保护的必要措施。
