title: Safety and immunogenicity of an inactivated split-virus influenza A/H1N1 vaccine in healthy children from 6 months to <18 years of age: a prospective, open-label, multi-center trial.
abstract: This study was conducted to determine the immunogenicity and safety of an inactivated split-virus influenza A/H1N1 vaccine in healthy Korean children from 6 months to <18 years of age. The immunization schedule consisted of two vaccinations, 21 days apart. The unadjuvanted vaccine contained 7.5microg (subjects 6 months to <3 years of age) or 15microg (subjects 3 to <18 years of age) of hemagglutinin antigen per dose. A total of 251 subjects were enrolled and 248 and 242 subjects, respectively, were included in the post-first dose and post-second dose immunogenicity evaluations conducted on a per protocol basis. By day 21, after the first dose, hemagglutination-inhibition titers of 1:40 or more were observed in 5.9% of subjects 6 months to <3 years of age, 34.9% of subjects 3 to <9 years of age and 81.4% of subjects 9-18 years of age. By day 21 after the second dose, the titer had been achieved 55.9%, 69.5% and 90.5%, respectively. No vaccination-related serious adverse events were observed. A single 15-microg dose of vaccine was highly immunogenic in subjects equal to or more than 9 years of age. However, a two-dose regimen is needed to produce potentially protective antibody titers in younger children.
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Republic of Korea.
authors.forename: Chi-Eun
authors.initials: CE
authors.lastname: Oh
authors.forename: Jina
authors.initials: J
authors.lastname: Lee
authors.forename: Jin-Han
authors.initials: JH
authors.lastname: Kang
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Hong
authors.forename: Yun-Kyung
authors.initials: YK
authors.lastname: Kim
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Cheong
authors.forename: Young-Joo
authors.initials: YJ
authors.lastname: Ahn
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Hoan-Jong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D011446:Prospective Studies; D056910:Republic of Korea; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated