Abstract
During 2010-2012 the strain composition of the influenza vaccine in the Southern Hemisphere did not change, but the circulating virus type/subtype did. We pooled data for these years from the Western Australian sentinel medical practice surveillance system for influenza to estimate vaccine effectiveness (VE) by influenza virus type and subtype. A case test-negative design was used with VE estimated as (1-odds ratio). ×. 100%. There were 2182 patients included in the analysis across the 3 years studied. The predominant subtype was A/H1pdm09 in 2010 and 2011, and A/H3 in 2012. The overall adjusted VE estimate against all influenza for 2010-2012 was 51% (95% CI: 36, 63). Estimates were highest against A/H1pdm09 at 74% (95% CI: 47, 87), followed by 56% (95% CI: 33, 71) for influenza B and lowest against A/H3 at 39% (95% CI: 13, 57). When analyses were restricted to compare influenza-positive patients with patients who tested positive for a non-influenza virus, overall adjusted VE was 59% (95% CI: 39, 72). These results suggest moderate protection against influenza by vaccination in Western Australia over the period 2010-2012, and are consistent with findings from other settings.
Original language | English |
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Pages (from-to) | 6312-6318 |
Number of pages | 7 |
Journal | Vaccine |
Volume | 32 |
Issue number | 47 |
DOIs | |
Publication status | Published - 29 Oct 2014 |
Externally published | Yes |
Keywords
- Data pooling
- Influenza
- Influenza season
- Influenza vaccine
- Influenza-like illness
- Vaccine effectiveness