Abstract

Continuous emergence of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), enhanced transmissibility, significant immune escape, and waning immunity call for booster vaccination. We evaluated the safety, immunogenicity, and efficacy of heterologous booster with a SARS-CoV-2 mRNA vaccine SYS6006 versus an active control vaccine in a randomized, open-label, active-controlled phase 3 trial in healthy adults aged 18 years or more who had received two or three doses of SARS-CoV-2 inactivated vaccine in China. The trial started in December 2022 and lasted for 6 months. The participants were randomized (overall ratio: 3:1) to receive one dose of SYS6006 (N = 2999) or an ancestral receptor binding region-based, alum-adjuvanted recombinant protein SARS-CoV-2 vaccine (N = 1000), including 520 participants in an immunogenicity subgroup. SYS6006 boosting showed good safety profiles with most AEs being grade 1 or 2, and induced robust wild-type and Omicron BA.5 neutralizing antibody response on Days 14 and 28, demonstrating immunogenicity superiority versus the control vaccine and meeting the primary objective. The relative vaccine efficacy against COVID-19 of any severity was 51.6% (95% CI, 35.5–63.7) for any variant, 66.8% (48.6–78.5) for BA.5, and 37.7% (2.4–60.3) for XBB, from Day 7 through Month 6. In the vaccinated and infected hybrid immune participants, the relative vaccine efficacy was 68.4% (31.1–85.5) against COVID-19 of any severity caused by a second infection. All COVID-19 cases were mild. SYS6006 heterologous boosting demonstrated good safety, superior immunogenicity and high efficacy against BA.5-associated COVID-19, and protected against XBB-associated COVID-19, particularly in the hybrid immune population.

Trial registration: Chinese Clinical Trial Registry: ChiCTR2200066941

Details

Title
The safety, immunogenicity, and efficacy of heterologous boosting with a SARS-CoV-2 mRNA vaccine (SYS6006) in Chinese participants aged 18 years or more: a randomized, open-label, active-controlled phase 3 trial
Author
Zhou, Chunhua 1 ; Qiu, Yuanzheng 2 ; Wang, Jianxin 1 ; Zhong, Xiang 2 ; Zhu, Xiufang 3 ; Huang, Xiaojing 3 ; Yang, Lan 3 ; Ji, Qiaolei 2 ; Zhou, Feifei 2 ; Wu, Shunquan 2 ; Yang, Mengjie 4 ; Zhang, Jing 4 ; Liu, Kaili 2 ; Li, Ji 2 ; Hanyu Yang 2 ; Li, Chunlei 2 ; Zhao, Yuanyuan 3 

 Department of Clinical Pharmacy, The First Hospital of Hebei Medical University, Shijiazhuang, People’s Republic of China; The Technology Innovation Center for Artificial Intelligence in Clinical Pharmacy of Hebei Province, Shijiazhuang, People’s Republic of China 
 CSPC Megalith Biopharmaceutical Co. Ltd, Shijiazhuang, People’s Republic of China 
 Department of Clinical Pharmacy, The First Hospital of Hebei Medical University, Shijiazhuang, People’s Republic of China 
 NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China 
Publication year
2024
Publication date
Dec 2024
Publisher
Taylor & Francis Ltd.
e-ISSN
22221751
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3142112517
Copyright
© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group, on behalf of Shanghai Shangyixun Cultural Communication Co., Ltd. This work is licensed under the Creative Commons  Attribution – Non-Commercial License http://creativecommons.org/licenses/by-nc/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.