The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Regular Contributions
Two Outbreaks of Influenza A (H3N2) in a Japanese Nursing Home in the Winter of 1996-1997, with Differing Vaccine Efficacy
Naoya MurayamaHiroshi SuzukiMasaaki ArakawaKuniaki NeromeKatsumi MizutaKohei Kameyama
Author information
JOURNAL FREE ACCESS

1999 Volume 188 Issue 4 Pages 289-298

Details
Abstract

Sixty of 128 (46.9%) residents of a nursing home were immunized with two doses of the trivalent split influenza vaccine. They developed 7.4-11.5-fold antibody increases, with a 69-82% protection rate, presenting good immune response rates to the influenza vaccine. Two outbreaks of influenza A (H3N2) occurred. There were no significant antigenic differences among the vaccine strain and the strains isolated from both outbreaks in haemagglutination-inhibition tests, suggesting that the second might have been a reoccurrence. There were no residents who were infected in both outbreaks. The vaccine efficacy against clinical illness in the first outbreak of typical influenza-like-illness (ILI) was 51% (relative risk: 0.49), and the febrile period was reduced significantly by vaccination. In the second outbreak, however, in which all patients had atypical ILI with a high fever but not respiratory symptoms, vaccine efficacy was not apparent for unknown reason.

Content from these authors
© 1999 Tohoku University Medical Press
Previous article Next article
feedback
Top