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Emerg Microbes Infect
. 2024 Dec;13(1):2320913.
doi: 10.1080/22221751.2024.2320913. Epub 2024 Feb 29. 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
Chunhua Zhou 1 2 , Yuanzheng Qiu 3 , Jianxin Wang 1 2 , Xiang Zhong 3 , Xiufang Zhu 1 , Xiaojing Huang 1 , Lan Yang 1 , Qiaolei Ji 3 , Feifei Zhou 3 , Shunquan Wu 3 , Mengjie Yang 4 , Jing Zhang 4 , Kaili Liu 3 , Li Ji 3 , Hanyu Yang 3 , Chunlei Li 3 , Yuanyuan Zhao 1
Affiliations
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.
Keywords: SARS-CoV-2; efficacy; heterologous boosting; immunogenicity; mRNA vaccine; safety.
. 2024 Dec;13(1):2320913.
doi: 10.1080/22221751.2024.2320913. Epub 2024 Feb 29. 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
Chunhua Zhou 1 2 , Yuanzheng Qiu 3 , Jianxin Wang 1 2 , Xiang Zhong 3 , Xiufang Zhu 1 , Xiaojing Huang 1 , Lan Yang 1 , Qiaolei Ji 3 , Feifei Zhou 3 , Shunquan Wu 3 , Mengjie Yang 4 , Jing Zhang 4 , Kaili Liu 3 , Li Ji 3 , Hanyu Yang 3 , Chunlei Li 3 , Yuanyuan Zhao 1
Affiliations
- PMID: 38860446
- PMCID: PMC10906127
- DOI: 10.1080/22221751.2024.2320913
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.
Keywords: SARS-CoV-2; efficacy; heterologous boosting; immunogenicity; mRNA vaccine; safety.