tetano
Editor, Senior Moderator
BMC Infect Dis
. 2025 May 25;25(1):750.
doi: 10.1186/s12879-025-11140-w. Immunogenicity and safety of a booster dose of the COVID-19 DNA vaccine in healthy adults aged 18 years and above: a single-center, randomized, observer-blind, placebo-controlled phase 2 trial
Aihua Yao[SUP] #[/SUP][SUP] 1 [/SUP], Siyue Jia[SUP] #[/SUP][SUP] 2 [/SUP], Xin Cheng[SUP] #[/SUP][SUP] 3 [/SUP], Hongxing Pan[SUP] 2 [/SUP], Zhijian Wang[SUP] 4 [/SUP], Haitao Yang[SUP] 2 [/SUP], Yu Xia[SUP] 3 [/SUP], Jianfang Xu[SUP] 4 [/SUP], Xuefen Huai[SUP] 3 [/SUP], Danjing Leng[SUP] 4 [/SUP], Ming Xu[SUP] 2 [/SUP], Jiarong Wang[SUP] 3 [/SUP], Gan Zhao[SUP] 3 [/SUP], Bin Wang[SUP] 5 [/SUP], Jingxin Li[SUP] 6 7 [/SUP]
Affiliations
Background: A two-dose primary regimen of INO-4800 DNA vaccine demonstrated only modest immunogenicity in the previous phase 2 clinical trial. This booster study aimed to evaluate the immunogenicity and safety of a booster dose of INO-4800 in adults previously received two-dose regimen of INO-4800.
Methods: Healthy adults who received two doses of INO-4800 (1.0 mg or 2.0 mg) at least 12 months ago in a previous phase 2 trial were eligible for this booster study, conducted in Danyang, Jiangsu Province, China. Eligible participants were stratified by primary vaccination dose (1.0 mg or 2.0 mg) and age group (18-59 years or ≥ 60 years), and subsequently randomized in a 1:1 ratio to receive a third dose of INO-4800 or placebo at the same dosage as previously administered. The primary immunogenicity endpoint was the geometric mean concentrations (GMCs) of spike-binding antibodies on day 14 post-booster. The primary safety endpoint was the occurrence of adverse reactions within 14 days.
Results: Between December 20 and 23, 2021, 200 eligible participants were enrolled. 100 eligible participants who received two doses of 2.0 mg INO-4800 were randomly assigned (1:1) to receive a third dose of 2.0 mg INO-4800 (n = 50) or 2.0 mg placebo (n = 50). Another 100 eligible participants who received two doses of 1.0 mg INO-4800 were randomly assigned (1:1) to receive a third dose of 1.0 mg INO-4800 (n = 50) or 1.0 mg placebo (n = 50). On day 14 post-booster, the GMCs of spike-binding antibodies were significantly higher in 2.0 mg INO-4800 group ( 260.1 BAU/mL) compared to placebo group (2.8 BAU/mL, p < 0.001), and in 1.0 mg INO-4800 group (104.2 BAU/mL) compared to placebo group (2.5 BAU/mL, p < 0.001). The most common local reactions were injection site redness, occurring at rate of 16.0% in the INO-4800 groups.All adverse reactions were mild to moderate in severity and occurred within 14 days post-booster. No vaccine related serious adverse events were reported.
Conclusions: The booster regimen of one dose INO-4800 is safe and modestly immunogenic in individuals who previously received a two- dose regimen of INO-4800, with the 2.0 mg INO-4800 demonstrating superior immunogenicity compared to the 1.0 mg INO-4800.
Trial registration: www.chictr.org.cn , identifier is ChiCTR2100054324.(December 13 2021).
Keywords: Booster immunization; COVID-19; DNA vaccine; Immunogenicity; Safety.
. 2025 May 25;25(1):750.
doi: 10.1186/s12879-025-11140-w. Immunogenicity and safety of a booster dose of the COVID-19 DNA vaccine in healthy adults aged 18 years and above: a single-center, randomized, observer-blind, placebo-controlled phase 2 trial
Aihua Yao[SUP] #[/SUP][SUP] 1 [/SUP], Siyue Jia[SUP] #[/SUP][SUP] 2 [/SUP], Xin Cheng[SUP] #[/SUP][SUP] 3 [/SUP], Hongxing Pan[SUP] 2 [/SUP], Zhijian Wang[SUP] 4 [/SUP], Haitao Yang[SUP] 2 [/SUP], Yu Xia[SUP] 3 [/SUP], Jianfang Xu[SUP] 4 [/SUP], Xuefen Huai[SUP] 3 [/SUP], Danjing Leng[SUP] 4 [/SUP], Ming Xu[SUP] 2 [/SUP], Jiarong Wang[SUP] 3 [/SUP], Gan Zhao[SUP] 3 [/SUP], Bin Wang[SUP] 5 [/SUP], Jingxin Li[SUP] 6 7 [/SUP]
Affiliations
- PMID: 40414851
- DOI: 10.1186/s12879-025-11140-w
Background: A two-dose primary regimen of INO-4800 DNA vaccine demonstrated only modest immunogenicity in the previous phase 2 clinical trial. This booster study aimed to evaluate the immunogenicity and safety of a booster dose of INO-4800 in adults previously received two-dose regimen of INO-4800.
Methods: Healthy adults who received two doses of INO-4800 (1.0 mg or 2.0 mg) at least 12 months ago in a previous phase 2 trial were eligible for this booster study, conducted in Danyang, Jiangsu Province, China. Eligible participants were stratified by primary vaccination dose (1.0 mg or 2.0 mg) and age group (18-59 years or ≥ 60 years), and subsequently randomized in a 1:1 ratio to receive a third dose of INO-4800 or placebo at the same dosage as previously administered. The primary immunogenicity endpoint was the geometric mean concentrations (GMCs) of spike-binding antibodies on day 14 post-booster. The primary safety endpoint was the occurrence of adverse reactions within 14 days.
Results: Between December 20 and 23, 2021, 200 eligible participants were enrolled. 100 eligible participants who received two doses of 2.0 mg INO-4800 were randomly assigned (1:1) to receive a third dose of 2.0 mg INO-4800 (n = 50) or 2.0 mg placebo (n = 50). Another 100 eligible participants who received two doses of 1.0 mg INO-4800 were randomly assigned (1:1) to receive a third dose of 1.0 mg INO-4800 (n = 50) or 1.0 mg placebo (n = 50). On day 14 post-booster, the GMCs of spike-binding antibodies were significantly higher in 2.0 mg INO-4800 group ( 260.1 BAU/mL) compared to placebo group (2.8 BAU/mL, p < 0.001), and in 1.0 mg INO-4800 group (104.2 BAU/mL) compared to placebo group (2.5 BAU/mL, p < 0.001). The most common local reactions were injection site redness, occurring at rate of 16.0% in the INO-4800 groups.All adverse reactions were mild to moderate in severity and occurred within 14 days post-booster. No vaccine related serious adverse events were reported.
Conclusions: The booster regimen of one dose INO-4800 is safe and modestly immunogenic in individuals who previously received a two- dose regimen of INO-4800, with the 2.0 mg INO-4800 demonstrating superior immunogenicity compared to the 1.0 mg INO-4800.
Trial registration: www.chictr.org.cn , identifier is ChiCTR2100054324.(December 13 2021).
Keywords: Booster immunization; COVID-19; DNA vaccine; Immunogenicity; Safety.