tetano
Editor, Senior Moderator
PLoS One. 2014 Nov 13;9(11):e112294. doi: 10.1371/journal.pone.0112294. eCollection 2014.
Influenza Vaccine Effectiveness in Preventing Influenza A(H3N2)-Related Hospitalizations in Adults Targeted for Vaccination by Type of Vaccine: A Hospital-Based Test-Negative Study, 2011-2012 A(H3N2) Predominant Influenza Season, Valencia, Spain.
Puig-Barber? J1, Garc?a-de-Lomas J2, D?ez-Domingo J3, Arnedo-Pena A4, Ruiz-Garc?a M4, Lim?n-Ram?rez R5, P?rez-Vilar S5, Mic?-Esparza JL6, Tortajada-Girb?s M7, Carratal?-Munuera C8, Larrea-Gonz?lez R9, Beltr?n-Garrido JM9, Otero-Reigada Mdel C10, Mollar-Maseres J10, Correcher-Medina P11, Schwarz-Chavarri G12, Gil-Guill?n V13; Valencia Hospital Network for the Study of Influenza and Respiratory Virus Disease.
Author information
Abstract
BACKGROUND:
Most evidence of the effectiveness of influenza vaccines comes from studies conducted in primary care, but less is known about their effectiveness in preventing serious complications. Here, we examined the influenza vaccine effectiveness (IVE) against hospitalization with PCR-confirmed influenza in the predominant A(H3N2) 2011-2012 influenza season.
METHODS:
A hospital-based, test-negative study was conducted in nine hospitals in Valencia, Spain. All emergency admissions with a predefined subset of symptoms were eligible. We enrolled consenting adults age 18 and over, targeted for influenza vaccination because of comorbidity, with symptoms of influenza-like-illness within seven days of admission. We estimated IVE as (1-adjusted vaccination odds ratio)*100 after accounting for major confounders, calendar time and recruitment hospital.
RESULTS:
The subjects included 544 positive for influenza A(H3N2) and 1,370 negative for influenza admissions. Age was an IVE modifying factor. Regardless of vaccine administration, IVE was 72% (38 to 88%) in subjects aged under 65 and 21% (-5% to 40%) in subjects aged 65 and over. By type of vaccine, the IVE of classical intramuscular split-influenza vaccine, used in subjects 18 to 64, was 68% (12% to 88%). The IVE for intradermal and virosomal influenza vaccines, used in subjects aged 65 and over, was 39% (11% to 58%) and 16% (-39% to 49%), respectively.
CONCLUSIONS:
The split-influenza vaccine was effective in preventing influenza-associated hospitalizations in adults aged under 65. The intradermal vaccine was moderately effective in those aged 65 and over.
PMID:
25392931
[PubMed - in process]
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/25392931
Influenza Vaccine Effectiveness in Preventing Influenza A(H3N2)-Related Hospitalizations in Adults Targeted for Vaccination by Type of Vaccine: A Hospital-Based Test-Negative Study, 2011-2012 A(H3N2) Predominant Influenza Season, Valencia, Spain.
Puig-Barber? J1, Garc?a-de-Lomas J2, D?ez-Domingo J3, Arnedo-Pena A4, Ruiz-Garc?a M4, Lim?n-Ram?rez R5, P?rez-Vilar S5, Mic?-Esparza JL6, Tortajada-Girb?s M7, Carratal?-Munuera C8, Larrea-Gonz?lez R9, Beltr?n-Garrido JM9, Otero-Reigada Mdel C10, Mollar-Maseres J10, Correcher-Medina P11, Schwarz-Chavarri G12, Gil-Guill?n V13; Valencia Hospital Network for the Study of Influenza and Respiratory Virus Disease.
Author information
Abstract
BACKGROUND:
Most evidence of the effectiveness of influenza vaccines comes from studies conducted in primary care, but less is known about their effectiveness in preventing serious complications. Here, we examined the influenza vaccine effectiveness (IVE) against hospitalization with PCR-confirmed influenza in the predominant A(H3N2) 2011-2012 influenza season.
METHODS:
A hospital-based, test-negative study was conducted in nine hospitals in Valencia, Spain. All emergency admissions with a predefined subset of symptoms were eligible. We enrolled consenting adults age 18 and over, targeted for influenza vaccination because of comorbidity, with symptoms of influenza-like-illness within seven days of admission. We estimated IVE as (1-adjusted vaccination odds ratio)*100 after accounting for major confounders, calendar time and recruitment hospital.
RESULTS:
The subjects included 544 positive for influenza A(H3N2) and 1,370 negative for influenza admissions. Age was an IVE modifying factor. Regardless of vaccine administration, IVE was 72% (38 to 88%) in subjects aged under 65 and 21% (-5% to 40%) in subjects aged 65 and over. By type of vaccine, the IVE of classical intramuscular split-influenza vaccine, used in subjects 18 to 64, was 68% (12% to 88%). The IVE for intradermal and virosomal influenza vaccines, used in subjects aged 65 and over, was 39% (11% to 58%) and 16% (-39% to 49%), respectively.
CONCLUSIONS:
The split-influenza vaccine was effective in preventing influenza-associated hospitalizations in adults aged under 65. The intradermal vaccine was moderately effective in those aged 65 and over.
PMID:
25392931
[PubMed - in process]
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/25392931