Evaluation of seasonal influenza vaccination effectiveness based on antibody efficacy among the institutionalized elderly in Japan.
Influenza vaccination efficacy was evaluated in 114 institutionalized elderly people in 2002/03. Strain A/H3N2 was isolated; 44 and 8 subjects had sudden-onset fever (> or = 37.8 degrees C) and kit-diagnosed influenza, respectively. Odds ratios adjusted for age, sex, comorbidity, and vaccine strain (OR(adj)) were determined using multiple logistic regression. Seroprotected patients (haemagglutination-inhibition antibody titre > or = 1:40) had lower incidence of fever (OR(adj), 0.35; 95% confidence interval [CI], 0.09-1.28) and kit-diagnosed influenza (OR(adj), 0.35; 95% CI, 0.03-4.64) than patients without seroprotection (antibody efficacy, approximately 65%). Seroprotective levels of vaccination-induced antibodies probably prevent influenza among the institutionalized elderly, although statistical significance could not be confirmed owing to the sample size.
Hara
Megumi
M
Department of Preventive Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan. harameg@cc.saga-u.ac.jp
Tanaka
Keitaro
K
Kase
Tetsuo
T
Maeda
Akiko
A
Hirota
Yoshio
Y
D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011446:Prospective Studies
D000914:Antibodies, Viral; D007252:Influenza Vaccines