H1N1 Influenza Pandemic in Italy Revisited: Has the Willingness to Get Vaccinated Suffered in the Long Run?

Ludolph, Ramona; Nobile, Marta; Hartung, Uwe; Castaldi, Silvana; Schulz, Peter J.

There is already a broad body of research that addresses the influence of various factors on a vaccination decision. A review of 60 international empirical studies on population reactions to recent pandemics such as severe acute respiratory syndrome (SARS), avian flu (H5N1) and H1N1 finds that the elderly adopt more protective behaviours including vaccination than younger people. 25 Further, women adopt more protective behaviours other than vaccination but are less willing to get immunised than men. 25 The variables perceived susceptibility to an infection, fear of severe consequences and trust in the effectiveness of a vaccine are also positively linked to the likelihood of adopting preventive measures including vaccination. 25 The same goes for anxiety, trust in authorities and past protective behaviours. 25 Kwon et al. pro- nounce also that beliefs about the safety of a vaccine play a paramount role in predicting behaviour. 26 As can be seen, most research focuses on socio-demographic, perceptual, psychological or attitudinal predictor variables and thus makes this a well-studied field. [27] [28] [29] Psychological variables include character traits such as anxiety or self-efficacy; an attitudinal variable can for instance be trust in government. A chief interest also lies with the perceptual variables. However, in most of the research the perceptual and behavioural predictors as well as the consequences refer to the same disease. The finding that past vaccination against the seasonal flu predicts an intention to get vaccinated against the new flu is an exception to this. 24, 30 Another exception are studies that attempt to predict vaccination behaviour with regard to a future hypothetical influenza pandemic. So far, there is not much research investigating this aspect. Only a few studies used hypothetical influenza pandemics to examine predictors of precautionary behaviours, ranging from personal measures such as wearing face masks, taking antiviral drugs and finally getting vaccinated to precautionary social behaviour like avoiding crowds. 12, [31] [32] [33] The investigated perceptual predictors in these studies refer, however, to the same hypothetical situation, not to any real experiences with actual threats. To date, there is only one study that links the specific real experiences and perceptions in living through a pandemic threat (H1N1) to a future hypothetical pandemic infection in order to study secondary effects of the past threat on willingness to seek vaccination in the future. 34 Yet, this study compares the public threat perception and the anticipated response to a future pandemic before and shortly after the H1N1 pandemic. 34 Therefore, no conclusions about potential long-term secondary effects of the 2009/10 pandemic can be made. Moreover, the authors did not take into account the public's perception of the institutional performance in handling the pandemic. Further, results from Italy are scarce. Prati et al. 35 indeed examined the perception of the pandemic threat on recommended behaviours in Italy but did not include vaccination. As immunization is by far the most efficacious protection against an influenza virus, the present article is concerned with the willingness to get vaccinated when the next influenza pandemic hits. To our knowledge this is the first study to assess the long-term secondary effects of personal experience with the H1N1 pandemic of 2009/10 and the perception of the institutional reaction to it