tetano
Editor, Senior Moderator
Hum Vaccin Immunother
. 2025 Dec;21(1):2468074.
doi: 10.1080/21645515.2025.2468074. Epub 2025 Feb 24. Immunogenicity and safety of 1 versus 2 doses of quadrivalent-inactivated influenza vaccine in children aged 3-8 years with or without previous influenza vaccination histories
Feng Wen[SUP] 1 [/SUP], Sheng Liu[SUP] 2 [/SUP], Li Zhou[SUP] 3 4 [/SUP], Yinbiao Zhu[SUP] 5 [/SUP], Wenjuan Wang[SUP] 3 6 [/SUP], Mingwei Wei[SUP] 3 6 [/SUP], Xinglong Xu[SUP] 5 [/SUP], Yan Liu[SUP] 5 [/SUP], Qi Shuai[SUP] 5 [/SUP], Jun Yu[SUP] 5 [/SUP], Pengfei Jing[SUP] 3 6 [/SUP], Jingxin Li[SUP] 1 3 6 [/SUP], Fengcai Zhu[SUP] 1 3 6 [/SUP]
Affiliations
This study assessed the immunogenicity and safety of a quadrivalent influenza split-virion vaccine (IIV4) in children with and without prior influenza vaccination. An open-label, phase IV clinical trial was conducted in healthy children aged 3-8 years in Pizhou, Jiangsu Province, China. Children with ≥2 doses of prior influenza vaccination (Influenza Vaccination Group) and those with no prior vaccination (Influenza Vaccine-naïve Group) were given two doses of IIV4, 4 weeks apart. The primary immunogenicity endpoints were seroprotection rates (SPRs) of hemagglutination inhibition antibody 28 days after each dose against influenza A/H1N1, A/H3N2, B/Yamagata (BY), and B/Victoria (BV). Safety endpoints included adverse events (AEs) within 28 days and serious adverse events (SAEs) within 6 months. Between September 19-25, 2021, 278 participants were screened, and 240 were enrolled (120 per group). In the Influenza Vaccination Group, SPRs after the 2nd dose were 98.28%, 92.24%, 99.14%, and 87.93%, similar to those after the 1st dose (all p > .05). In the Influenza Vaccine-naïve Group, SPRs after the 2nd dose were 99.12%, 96.49%, 99.12%, and 92.11%, significantly higher than after the 1st dose (p < .001 for all strains except BY, p = .070). Most AEs were mild or moderate, with no serious AEs related to the vaccine. Children aged 3-8 years with prior influenza vaccination need only one dose of IIV4, while those without prior vaccination require two doses. ClinicalTrials.gov, the identifier is NCT05144464.
Keywords: 1 versus 2 doses; Inactivated influenza vaccine; immunogenicity; previous influenza vaccination; safety.
. 2025 Dec;21(1):2468074.
doi: 10.1080/21645515.2025.2468074. Epub 2025 Feb 24. Immunogenicity and safety of 1 versus 2 doses of quadrivalent-inactivated influenza vaccine in children aged 3-8 years with or without previous influenza vaccination histories
Feng Wen[SUP] 1 [/SUP], Sheng Liu[SUP] 2 [/SUP], Li Zhou[SUP] 3 4 [/SUP], Yinbiao Zhu[SUP] 5 [/SUP], Wenjuan Wang[SUP] 3 6 [/SUP], Mingwei Wei[SUP] 3 6 [/SUP], Xinglong Xu[SUP] 5 [/SUP], Yan Liu[SUP] 5 [/SUP], Qi Shuai[SUP] 5 [/SUP], Jun Yu[SUP] 5 [/SUP], Pengfei Jing[SUP] 3 6 [/SUP], Jingxin Li[SUP] 1 3 6 [/SUP], Fengcai Zhu[SUP] 1 3 6 [/SUP]
Affiliations
- PMID: 39993940
- DOI: 10.1080/21645515.2025.2468074
This study assessed the immunogenicity and safety of a quadrivalent influenza split-virion vaccine (IIV4) in children with and without prior influenza vaccination. An open-label, phase IV clinical trial was conducted in healthy children aged 3-8 years in Pizhou, Jiangsu Province, China. Children with ≥2 doses of prior influenza vaccination (Influenza Vaccination Group) and those with no prior vaccination (Influenza Vaccine-naïve Group) were given two doses of IIV4, 4 weeks apart. The primary immunogenicity endpoints were seroprotection rates (SPRs) of hemagglutination inhibition antibody 28 days after each dose against influenza A/H1N1, A/H3N2, B/Yamagata (BY), and B/Victoria (BV). Safety endpoints included adverse events (AEs) within 28 days and serious adverse events (SAEs) within 6 months. Between September 19-25, 2021, 278 participants were screened, and 240 were enrolled (120 per group). In the Influenza Vaccination Group, SPRs after the 2nd dose were 98.28%, 92.24%, 99.14%, and 87.93%, similar to those after the 1st dose (all p > .05). In the Influenza Vaccine-naïve Group, SPRs after the 2nd dose were 99.12%, 96.49%, 99.12%, and 92.11%, significantly higher than after the 1st dose (p < .001 for all strains except BY, p = .070). Most AEs were mild or moderate, with no serious AEs related to the vaccine. Children aged 3-8 years with prior influenza vaccination need only one dose of IIV4, while those without prior vaccination require two doses. ClinicalTrials.gov, the identifier is NCT05144464.
Keywords: 1 versus 2 doses; Inactivated influenza vaccine; immunogenicity; previous influenza vaccination; safety.