title: Effect of prior vaccination with a seasonal trivalent influenza vaccine on the antibody response to the influenza pandemic H1N1 2009 vaccine: a randomized controlled trial.
abstract: Vaccination with the non-adjuvanted split-virion A/California/7/2009 influenza vaccine (pandemic H1N1 2009 vaccine) began in October 2009 in Japan. The present study was designed to assess the effect of prior vaccination with a seasonal trivalent influenza vaccine on the antibody response to the pandemic H1N1 2009 vaccine in healthy adult volunteers. One hundred and seventeen participants aged 22 to 62 were randomly assigned to two study groups. In Group 1 (the priming group), participants were first vaccinated with the seasonal trivalent influenza vaccine followed by two separate one-dose vaccinations of the pandemic H1N1 2009 vaccine, whereas in Group 2 (the non-priming group), the participants were first vaccinated with one dose of the pandemic H1N1 2009 vaccine, followed by simultaneous vaccination of the seasonal trivalent vaccine and the second dose of the pandemic H1N1 2009 vaccine. The participants in Group 2 had a seroprotection rate (SPR) of 79.7% and a seroconversion rate (SCR) of 79.7% in the hemagglutination-inhibition test after the first dose of the pandemic H1N1 2009 vaccine, indicating that the pandemic H1N1 2009 vaccine is sufficiently immunogenic. On the other hand, the participants of Group 1 had a significantly weaker antibody response, with a SPR of 60.8% and a SCR of 58.5%. These results indicate that prior vaccination with the seasonal trivalent influenza vaccine inhibits the antibody response to the pandemic H1N1 2009 vaccine. Therefore, the pandemic H1N1 2009 vaccine should be administered prior to vaccination with the seasonal trivalent influenza vaccine.
authors: The Chemo-Sero-Therapeutic Research Institute (Kaketsuken), Headquarters, Kumamoto 860-8568 Kikuchi Research Center, Kumamoto 869-1298, Japan. uno-shi@kaketsuken.or.jp
authors: Shingo
authors: S
authors: Uno
authors: Kazuhiko
authors: K
authors: Kimachi
authors: Junko
authors: J
authors: Kei
authors: Keiichiro
authors: K
authors: Miyazaki
authors: Ayano
authors: A
authors: Oohama
authors: Tomohiro
authors: T
authors: Nishimura
authors: Kayo
authors: K
authors: Ibaragi
authors: Koichi
authors: K
authors: Odoh
authors: Yasuhiro
authors: Y
authors: Kudo
authors: Yoichiro
authors: Y
authors: Kino
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D006805:Human Experimentation; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D014611:Vaccination / Q000379:methods*
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines