Data Source
The source of cases of laboratory-acquired infection was the Chinese academic database: CNKI (www.cnki.net), Wanfang (www.wanfangdata.com.cn). Similarly, the reported S2 vaccine outbreak events were collected in this academic database and also the internet. The search terms were ”Brucella,” ”brucellosis,” ”laboratory-acquired infection” or ”hospital-acquired infection,” S2 vaccine infection events; Search field: Keyword, Abstract, and full article; search language: Chinese; the retrieval time: from the construction of the databases to June 2, 2020. Excel 2016 (Microsoft, Redmond, WA, USA) was used for data processing and analysis.