title: Low level of seroconversion after a novel influenza A/H1N1/2009 vaccination in Japanese patients with rheumatoid arthritis in the 2009 season.
abstract: We examined change in the antibody titre against pandemic influenza A/H1N1/2009 before and after vaccination in Japanese patients with rheumatoid arthritis. This observational study was conducted with the participation of five hospitals in Japan. A total of 89 patients with rheumatoid arthritis were included in this study. The seroprotection and seroresponse rates to vaccination with the pandemic influenza A/H1N1/2009 vaccine were analysed. The seroprotection rates prior to the vaccination were 5.6% in the Japanese patients with rheumatoid arthritis. The seroprotection rates after subcutaneous vaccination were 55.1%. The seroresponse rate after subcutaneous vaccination was 50.6% in the patients with rheumatoid arthritis. Both the seroprotection and seroresponse rates obtained after the vaccination with the pandemic influenza A/H1N1/2009 vaccine were low in Japanese patients with rheumatoid arthritis. We should realise that a vaccination against this newly emerged influenza virus may protect only half of the Japanese patients with rheumatoid arthritis in a real world.
authors: Division of Rheumatology and Clinical Immunology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan. hiro-iwa@jichi.ac.jp
authors: Masahiro
authors: M
authors: Iwamoto
authors: Sumiko
authors: S
authors: Homma
authors: Sachiko
authors: S
authors: Onishi
authors: Yasuyuki
authors: Y
authors: Kamata
authors: Katsuya
authors: K
authors: Nagatani
authors: Zentaro
authors: Z
authors: Yamagata
authors: Seiji
authors: S
authors: Minota
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D007564:Japan; D008297:Male; D008875:Middle Aged
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines