2001 Fiscal Year Final Research Report Summary
Clinico-epidemiological and Immunological Study on Influenza Vaccine and the Countermeasures against Influenza Pandemic
| Project/Area Number |
10470109
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Public health/Health science
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| Research Institution | Osaka City University (1999-2001)
Kyushu University (1998) |
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Principal Investigator |
HIROTA Yoshio Osaka City University Graduate School of Medicine, Department of Public Health, Professor, 大学院・医学研究科, 教授 (20080624)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Takashi Osaka City University Graduate School of Medicine, Department of Public Health, Lecture, 大学院・医学研究科, 講師 (30227144)
TOKUNAGA Shohji Kyushu University Graduate School of Medicine, Department of Preventive Medicine, Research Associate, 大学院・医学研究院, 助手 (50227584)
KIYOHARA Chikako Kyushu University Graduate School of Medicine, Department of Preventive Medicine, Lecture, 大学院・医学研究院, 講師 (00169963)
YAMASHITA Terumi Osaka City University Graduate School of Medicine, Department of Public Health, Research Associate, 大学院・医学研究科, 助手 (50094496)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Influenza / Vaccine / Elderly / Epidemic / Antibody efficacy / Vaccine efficacy / Adverse event / Hem agglutination inhibition antibody |
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| Research Abstract |
To establish the basis of countermeasures against annual influenza epidemic and anticipated next influenza pandemic, we investigated vaccine effectiveness and immune responses in the elderly persons.
In the 1997-1998 season, the epidemic scale was too small to assess vaccine efficacy (a comparison of the frequency of influenza-like illness (ILI) between the vaccinees and the nonvaccinees). We therefore evaluated antibody efficacy (a comparison of the frequency of ILI between those with and those without a protective level of pre-epidemic hemagglutination inhibition (HAI antibody). Odds ratio (OR) for ILI with fever >= 38 ℃ was 0.14 among those with HAI titer >= l : 256 as compared to those with titer =< 1 : 128, after adjusting underlying health conditions (antibody efficacy: 86 %). The proportion of those with prevaccination titer =< 1 : 128 who acquired postvaccination titer >= 1 : 256 was 71% (achievement rate). As a result, vaccine efficacy was estimated to be 61% as a product of 0.86×0.71.
In the 1998-1999 season, vaccine efficacy was calculable because of somewhat greater epidemic. The adjusted relative risks (RR) of vaccinees as compared to nonvaccinees were 0.74〜0.79 for ILI with fever >= 38 ℃ and 0.50〜0.54 for ILI with fever >= 39 ℃, and 0.43 for death among those contracted ILI withfever >= 38 ℃.
In the 1999-2000 season, we focused the study on the antibody responses to two-dose vaccination, because epidemic scale was trivial. No significant titer rise was observed after the second dose vaccination. The similar results were obtained for the healthy adults. They revealed appreciable response to the first dose. Thus, single dose vaccination can be recommended.
The elderly persons with low ADL showed six-fold greater risk for ILI. The frequency of adverse events within 48 hours after vaccination were 0.8〜2 % for fever >= 38 ℃, and 3.2-4 % for swelling on injection site.
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