Negative trends from 2008/9 to 2011/12 seasons in influenza vaccination coverages among high risk subjects and health care workers in Spain

Abstract

Objectives: We aim to describe influenza vaccination coverage for the Spanish population across four consecutive campaigns (2008/2009 to 2011/2012). The data was analyzed by high risk groups and health care workers (HCWs). Also, coverage trends were analyzed to assess uptake in post-pandemic seasons.

Methods: We used data from two nation-wide representative health surveys namely the 2009/10 European Health Interview Survey for Spain (N=22,188) and the 2011-12 Spanish National Health Survey (N=21,007) Influenza vaccination status was self-reported. We analyzed influenza vaccine coverage by age, sex, number of chronic conditions, being a heath care worker (HCWs) and nationality. Time trends for campaigns among high risk groups were estimated by a multivariate logistic regression model.

Results: We analyzed data from 43,072 subjects aged ≥ 16 years. As a whole, coverage decreased by 3.31% (22.57-19.26%) between the 2008/2009 and 2011/2012 campaigns with a significant decreasing trend (OR 0.92; 95% CI: 0.90-0.94). Coverage in people under 60 years with a chronic disease decreased significantly (OR 0.92: 95% CI: 0.85-0.99) during the analyzed period from 21.02% in 2008/2009 to 17.40% in 2011/2012. Among HCWs, the highest influenza vaccination coverage was achieved in 2009/2010 (31.08%) in the latest campaign coverage has almost halved (17.88%). For the 2011/2012 season and for all age groups the variables associated with a higher probability of having received the influenza vaccine were older age and presence of associated chronic conditions. Among those aged ≥ 60 years, immigrants had lower uptake (OR 0.60; 95% CI: 0.32-0.99).

Conclusions: Seasonal influenza vaccine uptake rates in the recommended target groups in Spain are unacceptably low and seem to be decreasing in the post pandemic seasons. Further studies are necessary to precisely identify reasons for non-compliance and barriers to influenza vaccination. Meanwhile urgent strategies to improve seasonal vaccination uptake must be discussed and implemented.

Keywords: Coverage; Influenza; Public health policy; Trends; Vaccines.