title: [A study on the HA amount of HA influenza vaccination on efficacy and safety in infants].
abstract: We examined the efficacy and safety of inactivated influenza vaccine when the amount of HA influenza vaccination in children was increased to the dose recommended by the WHO. The purpose of this study was to obtain basic evidence to review the vaccination dose in Japanese children. HA influenza vaccine produced by the Research Foundation for Microbial Diseases of Osaka University (Biken) licenced in Japan was administered through vaccination at the international dose, and split HA influenza vaccine produced by Sanofi Pasteur corp. (Sanofi) was used as control. Children from 6 months to less than 13 years of age were registered, and vaccinated with doses of 0.25 mL or 0.5 mL. Clinical symptoms during the influenza season were monitored to investigate vaccine efficacy, and information on adverse reactions was collected to evaluate safety profile. Paired serum HI and NT antibody titers were measured at pre first dose and post second dose of vaccination. Both HI and NT antibody titers for H1N1 subtype were satisfactory elevated after administration of both vaccines. Elevation of the NT antibody titer for the H3N2 subtype was observed for both vaccines, but the H3N2 HI antibody titer for the Biken vaccine was not so high. For the subtype B virus, the NT titer had a better response than the HI titer for both vaccines. As only the H1N1 virus was prevalent in the area during the study period, we performed factor analysis concerning influenza contraction only for the H1N1 antibody titer. An HI titer of 1 : 40 or more at post-vaccination was a significant factor to lower the risk of influenza contraction. The relative risk for fever among children with an HI titer of 1 : 20 or less was significantly higher than those with an HI titer of 1 : 40 or more. Children with a higher HI titer had better prevention against fever, so that both vaccines were considered to be effective. As for the appearance of adverse reactions, both vaccines were considered to be safe. From the above-mentioned results, vaccination with the Japanese Biken vaccine at an international dose was thought to be an effective and safe procedure.
authors.affiliation: Mie Prefecture Health and Environment Research Institute.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Takuya
authors.initials: T
authors.lastname: Yano
authors.forename: Miwa
authors.initials: M
authors.lastname: Fukuta
authors.forename: Akinori
authors.initials: A
authors.lastname: Yamauchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Okuma
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ihara
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsuda
authors.forename: Sadayoshi
authors.initials: S
authors.lastname: Torigoe
authors.forename: Ritsue
authors.initials: R
authors.lastname: Nii
authors.forename: Machiko
authors.initials: M
authors.lastname: Isaji
authors.forename: Masahiro
authors.initials: M
authors.lastname: Watanabe
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ochiai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakatoku
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Maeda
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Okuno
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kamiya
mesh_terms: D000293:Adolescent; D000906:Antibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D007564:Japan; D008297:Male; D016896:Treatment Outcome; D014611:Vaccination / Q000009:adverse effects* / Q000706:statistics & numerical data
chemical_list: D000906:Antibodies; D007252:Influenza Vaccines