Effectiveness of inactivated influenza vaccine against laboratory-confirmed influenza among Chinese elderly: a test-negative design.
BMC Geriatr
; 24(1): 404, 2024 May 07.
Article
en En
| MEDLINE
| ID: mdl-38714944
ABSTRACT
BACKGROUND:
Evidence on the effectiveness of influenza vaccination in the elderly is limited, and results are controversial. There are also few reports from China.METHODS:
We conducted a test-negative case-control study design to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated visits among elderly (aged ≥ 60 years) across four influenza seasons in Ningbo, China, from 2018 to 19 to 2021-22. Influenza-positive cases and negative controls were randomly matched in a 11 ratio according to age, sex, hospital, and date of influenza testing. We used logistic regression models to compare vaccination odds ratios (ORs) in cases to controls. We calculated the VE as [100% × (1-adjusted OR)] and calculated the 95% confidence interval (CI) around the estimate.RESULTS:
A total of 30,630 elderly patients tested for influenza with virus nucleic acid or antigen during the study period. After exclusions, we included 1 825 influenza-positive cases and 1 825 influenza-negative controls. Overall, the adjusted VE for influenza-related visits was 63.5% (95% CI, 56.3-69.5%), but varied by season. Influenza VE was 59.8% (95% CI, 51.5-66.7%) for influenza A and 89.6% (95% CI, 77.1-95.3%) for influenza B. The VE for ages 60-69 and 70-79 was 65.2% (95% CI, 55.4-72.9%) and 69.8% (95% CI, 58.7-77.9%), respectively, but only 45.4% (95% CI, 6.2-68.2%) for ages 80 and over.CONCLUSIONS:
Standard-dose inactivated influenza vaccine has shown good protection in the elderly in China. However, protection may not be satisfactory in people aged 80 years and older.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Vacunas contra la Influenza
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Vacunas de Productos Inactivados
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Gripe Humana
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Eficacia de las Vacunas
Límite:
Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
País/Región como asunto:
Asia
Idioma:
En
Revista:
BMC Geriatr
Asunto de la revista:
GERIATRIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
China