Real-World Effectiveness of Primary Series and Booster Doses of Inactivated Coronavirus Disease 2019 Vaccine Against Omicron BA.2 Variant Infection in China: A Retrospective Cohort Study

Autor: Lin Tang, Fu-Zhen Wang, Lance E Rodewald, Xuan-Yi Wang, Si-Yu Liu, Qian-Qian Liu, Xiao-Qi Wang, Dan Wu, Ming-Shuang Li, Qian Zhang, Yi-Ming Shao, Li-Fang Huang, Yu-Dan Song, Yong Huang, Xiang Zeng, Li-Jun Liu, Hong Yang, Ao-Di Huang, Li-Ming Bao, Hui Zheng, Chao Ma, Xiao-Ya Lv, Lei Song, Zhao Ma, Shu-Guang Wang, Hao Ma, Wei-Jie Guan, Zhi-Yin Wu, Nan-Shan Zhong, Zun-Dong Yin
Rok vydání: 2023
Předmět:
Zdroj: The Journal of Infectious Diseases.
ISSN: 1537-6613
0022-1899
Popis: Background 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. Methods 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. Results 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. Conclusions 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.
Databáze: OpenAIRE
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