tetano
Editor, Senior Moderator
BMC Infect Dis
. 2025 Nov 20;25(1):1625.
doi: 10.1186/s12879-025-12053-4. Safety, immunogenicity, persistence and dose evaluation of the CS-2034 mRNA COVID-19 vaccine: a phase II randomized controlled trial in healthy Chinese adults
Zhili Jin[SUP] #[/SUP][SUP] 1 [/SUP], Jingxuan Wu[SUP] #[/SUP][SUP] 1 [/SUP], Tao Huang[SUP] 2 [/SUP], Kexin Zhao[SUP] 3 [/SUP], Meijuan Zhang[SUP] 1 [/SUP], Jun Liu[SUP] 1 [/SUP], Jian Song[SUP] 1 [/SUP], Hang Yin[SUP] 1 [/SUP], Xiaofang Wu[SUP] 1 [/SUP], Jian Liu[SUP] 4 5 6 [/SUP], Tao Zhu[SUP] 5 6 [/SUP], Haitao Huang[SUP] 6 [/SUP], Jin Li[SUP] 4 5 6 [/SUP], Haomeng Wang[SUP] 4 5 6 [/SUP], Jinbo Gou[SUP] 6 [/SUP], Ruihua Dong[SUP] 7 [/SUP]
Affiliations
Background: Our objective was to evaluate the safety and immunogenicity of the COVID-19 mRNA vaccine (CS-2034) in Chinese adults, and to determine the optimal dosage with a favorable safety and immunogenicity profile.
Methods: This study was a phase II clinical trial conducted across multiple centers, employing a randomized, double-blinded, dose-exploration, placebo-controlled design which was registered at ClinicalTrials.gov under the identifier NCT05373472 (registration date: May 13, 2022).
Results: A total of 150 participants were randomized into low-dose vaccine, high-dose vaccine, and placebo groups. The vaccine CS-2034 was well tolerated, with adverse reactions largely mild to moderate and comparable across dose groups. Both dose levels induced strong neutralizing antibody responses against the ancestral SARS-CoV-2 strain, with high seroconversion and evidence of antibody persistence over time. In contrast, neutralizing activity against the Omicron BA.1 variant was limited and declined further after the peak response.
Conclusions: The 0.3 mL dose (low-dose vaccine) was selected for further development based on comparable immunogenicity and lower reactogenicity.
Clinical trial registration: The study was registered at ClinicalTrials.gov under the identifier NCT05373472 (registration date: May 13, 2022).
Keywords: COVID-19; Immunogenicity; Persistence; Safety; mRNA vaccine.
. 2025 Nov 20;25(1):1625.
doi: 10.1186/s12879-025-12053-4. Safety, immunogenicity, persistence and dose evaluation of the CS-2034 mRNA COVID-19 vaccine: a phase II randomized controlled trial in healthy Chinese adults
Zhili Jin[SUP] #[/SUP][SUP] 1 [/SUP], Jingxuan Wu[SUP] #[/SUP][SUP] 1 [/SUP], Tao Huang[SUP] 2 [/SUP], Kexin Zhao[SUP] 3 [/SUP], Meijuan Zhang[SUP] 1 [/SUP], Jun Liu[SUP] 1 [/SUP], Jian Song[SUP] 1 [/SUP], Hang Yin[SUP] 1 [/SUP], Xiaofang Wu[SUP] 1 [/SUP], Jian Liu[SUP] 4 5 6 [/SUP], Tao Zhu[SUP] 5 6 [/SUP], Haitao Huang[SUP] 6 [/SUP], Jin Li[SUP] 4 5 6 [/SUP], Haomeng Wang[SUP] 4 5 6 [/SUP], Jinbo Gou[SUP] 6 [/SUP], Ruihua Dong[SUP] 7 [/SUP]
Affiliations
- PMID: 41267026
- PMCID: PMC12632088
- DOI: 10.1186/s12879-025-12053-4
Background: Our objective was to evaluate the safety and immunogenicity of the COVID-19 mRNA vaccine (CS-2034) in Chinese adults, and to determine the optimal dosage with a favorable safety and immunogenicity profile.
Methods: This study was a phase II clinical trial conducted across multiple centers, employing a randomized, double-blinded, dose-exploration, placebo-controlled design which was registered at ClinicalTrials.gov under the identifier NCT05373472 (registration date: May 13, 2022).
Results: A total of 150 participants were randomized into low-dose vaccine, high-dose vaccine, and placebo groups. The vaccine CS-2034 was well tolerated, with adverse reactions largely mild to moderate and comparable across dose groups. Both dose levels induced strong neutralizing antibody responses against the ancestral SARS-CoV-2 strain, with high seroconversion and evidence of antibody persistence over time. In contrast, neutralizing activity against the Omicron BA.1 variant was limited and declined further after the peak response.
Conclusions: The 0.3 mL dose (low-dose vaccine) was selected for further development based on comparable immunogenicity and lower reactogenicity.
Clinical trial registration: The study was registered at ClinicalTrials.gov under the identifier NCT05373472 (registration date: May 13, 2022).
Keywords: COVID-19; Immunogenicity; Persistence; Safety; mRNA vaccine.