| Title |
Repeated influenza vaccination for preventing severe and fatal influenza infection in older adults: a multicentre case–control study
|
|---|---|
| Published in |
Canadian Medical Association Journal, January 2018
|
| DOI | 10.1503/cmaj.170910 |
| Pubmed ID | |
| Authors |
Itziar Casado, Ángela Domínguez, Diana Toledo, Judith Chamorro, Jenaro Astray, Mikel Egurrola, María Amelia Fernández-Sierra, Vicente Martín, María Morales-Suárez-Varela, Pere Godoy, Jesús Castilla |
| Abstract |
The effectiveness of repeated vaccination for influenza to prevent severe cases remains unclear. We evaluated the effectiveness of influenza vaccination on preventing admissions to hospital for influenza and reducing disease severity. We conducted a case-control study in 20 hospitals in Spain during the 2013/14 and 2014/15 influenza seasons. Community-dwelling adults aged 65 years or older who were admitted to hospital for laboratory-confirmed influenza were matched with inpatient controls by sex, age, hospital and admission date. The effectiveness of vaccination in the current and 3 previous seasons in preventing influenza was estimated for inpatients with nonsevere influenza and for those with severe influenza who were admitted to intensive care units (ICUs) or who died. We enrolled 130 inpatients with severe and 598 with nonsevere influenza who were matched to 333 and 1493 controls, respectively. Compared with patients who were unvaccinated in the current and 3 previous seasons, adjusted effectiveness of influenza vaccination in the current and any previous season was 31% (95% confidence interval [CI] 13%-46%) in preventing admission to hospital for nonsevere influenza, 74% (95% CI 42%-88%) in preventing admissions to ICU and 70% (95% CI 34%-87%) in preventing death. Vaccination in the current season only had no significant effect on cases of severe influenza. Among inpatients with influenza, vaccination in the current and any previous season reduced the risk of severe outcomes (adjusted odds ratio 0.45, 95% CI 0.26-0.76). Among older adults, repeated vaccination for influenza was twice as effective in preventing severe influenza compared with nonsevere influenza in patients who were admitted to hospital, which is attributable to the combination of the number of admissions to hospital for influenza that were prevented and reduced disease severity. These results reinforce recommendations for annual vaccination for influenza in older adults. |
X Demographics
The data shown below were collected from the profiles of 143 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 29 | 20% |
| Canada | 24 | 17% |
| Japan | 8 | 6% |
| Spain | 5 | 3% |
| Sweden | 3 | 2% |
| Argentina | 3 | 2% |
| Colombia | 3 | 2% |
| Mexico | 3 | 2% |
| China | 1 | <1% |
| Other | 11 | 8% |
| Unknown | 53 | 37% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 105 | 73% |
| Practitioners (doctors, other healthcare professionals) | 25 | 17% |
| Scientists | 13 | 9% |
Mendeley readers
The data shown below were compiled from readership statistics for 83 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 83 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 17 | 20% |
| Student > Master | 11 | 13% |
| Other | 8 | 10% |
| Professor > Associate Professor | 8 | 10% |
| Student > Ph. D. Student | 7 | 8% |
| Other | 18 | 22% |
| Unknown | 14 | 17% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 22 | 27% |
| Nursing and Health Professions | 11 | 13% |
| Agricultural and Biological Sciences | 6 | 7% |
| Immunology and Microbiology | 4 | 5% |
| Biochemistry, Genetics and Molecular Biology | 3 | 4% |
| Other | 11 | 13% |
| Unknown | 26 | 31% |
Attention Score in Context
This research output has an Altmetric Attention Score of 547. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 30 November 2023.
All research outputs
#45,251
of 25,732,188 outputs
Outputs from Canadian Medical Association Journal
#78
of 9,541 outputs
Outputs of similar age
#1,026
of 451,568 outputs
Outputs of similar age from Canadian Medical Association Journal
#1
of 111 outputs
Altmetric has tracked 25,732,188 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 99th percentile: it's in the top 5% of all research outputs ever tracked by Altmetric.
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