The safety and immunogenicity of an inactivated SARS-CoV-2 vaccine in Chinese adults aged 18–59 years: A phase I randomized, double-blinded, controlled trial

• DOI: 10.1016/j.vaccine.2021.04.006
• Publication Date: 2021-04-09T16:33:31Z
• Authors: Jing Pu; Qin Yu; Zhifang Yin; Ying Zhang; Xueqi Li; Qiongzhou Yin; Hongbo Chen; Runxiang Long; Zhimei Zhao; Tangwei Mou; Heng Zhao; Shiyin Feng; Zhongping Xie; Lichun Wang; Zhanlong He; Yun Liao; Shengtao Fan; Ruiju Jiang; Jianfeng Wang; Lingli Zhang; Jing Li; Huiwen Zheng; Pingfang Cui; Guorun Jiang; Lei Guo; Mingjue Xu; Huijuan Yang; Shan Lu; Xuanyi Wang; Yang Gao; Xingli Xu; Linrui Cai; Jian Zhou; Li Yu; Zhuo Chen; Chao Hong; Dan Du; Hongling Zhao; Yan Li; Kaili Ma; Yunfei Ma; Donglan Liu; Shibao Yao; Changgui Li; Yanchun Che; Longding Liu; Qihan Li
• Keywords: Seroconversion

This study examined the safety and immunogenicity of an inactivated SARS-CoV-2 vaccine.In a phase I randomized, double-blinded, placebo-controlled trial involving 192 healthy adults 18-59 years old, two injections of three doses (50 EU, 100 EU, 150 EU) of an inactivated SARS-CoV-2 vaccine or placebo were administered intramuscularly at a 2- or 4-week interval. The safety and immunogenicity of the vaccine were evaluated.Vaccination was completed in 191 subjects. Forty-four adverse reactions occurred within 28 days, most commonly mild pain and redness at the injection site or slight fatigue. At days 14 and 28, the seroconversion rates were 87.5% and 79.2% (50 EU), 100% and 95.8% (100 EU), and 95.8% and 87.5% (150 EU), respectively, with geometric mean titers (GMTs) of 18.1 and 10.6, 54.5 and 15.4, and 37.1 and 18.5, respectively, for the schedules with 2-week and 4-week intervals. Seroconversion was associated with synchronous upregulation of antibodies against the S protein, N protein and virion and a cytotoxic T lymphocyte (CTL) response. No cytokines and immune cells related to immunopathology were observed. Transcriptome analysis revealed the genetic diversity of immune responses induced by the vaccine.In a population aged 18-59 years in this trial, this inactivated SARS-CoV-2 vaccine was safe and immunogenic.CTR20200943 and NCT04412538.