Our results make it possible to better understand HCWs’ choices regarding influenza vaccination.
First of all, it is necessary to point out that a very small group of workers (only 4, which corresponds to 2.3% of the original sample) decided to only get vaccinated against pandemic influenza. In other words, people get vaccinated against pandemic influenza primarily in addition to the seasonal vaccine. One possible explanation is that HCWs assigns less importance to the consequences of the A-H1N1 virus than the seasonal virus. This result is in line with previous research .
It has already been shown that age is an important variable in determining the choice of the vaccine . As we can see, people who decided to get vaccinated were older than those who decided to not get vaccinated. Both national and regional legislation  encourages people over 65 years old to get vaccinated, but in this sample no worker was over 65 (Influenza Prevention and control, Italian Ministry of Health). However, if it is true that the probability of being affected by chronic disorders rises as age increases, in our sample we found no correlations between age and belonging to a category at risk, and living with, or being close to, family members who belong to a category at risk (all significant levels are between .372 and .961).
The multinomial logistic regression also confirmed that age is an important predictive factor.
We can assume that among HCWs, because of the type of job, and because of their seniority (several years spent in health care professions), older respondents could feel a stronger sense of belonging and, therefore, could more closely identify with the values of the public health service.
The ‘public health’ reasons for getting vaccinated against seasonal influenza have higher values among HCWs who received both vaccinations than those who did not get any vaccination. However, having a high level of agreement with ‘public health’ reasons was not strongly related with the decision to get both vaccinations, or only the seasonal vaccination.
Thus, we can state that knowledge is the key factor for the choice to uptake the seasonal and pandemic vaccine. HCWs are usually informed via a campaign by health departments about seasonal influenza vaccine: the mere communication about the importance of a vaccine does not, therefore, seem sufficient. In other words, workers are subjected to the same stimulus (a yearly vaccination campaign with the same content), and they tend to get used to them. We cannot say the same for pandemic influenza vaccine, as it is not an ordinary event. In this case, the stimulus is new and more prominent, so that detailed information about vaccination makes the difference in making the choice.
In addition, we can imagine that in that specific moment, when the mass media invested a large amount of time discussing pandemic influenza, the information related to getting vaccinated against pandemic influenza had the largest impact. This conclusion is in line with previous research , which found that the most common reasons underlying an unwillingness or hesitation to get the vaccine against pandemic influenza were the possible side effects and lack of comprehensive field evaluation before marketing.
In fact, the reasons regarding ‘awareness of vaccine safety and side effects’ on the pandemic influenza vaccine were determinant in predicting the vaccination choice. This is due to the fact that the reporting of a higher level of agreement in having received enough information has a positive effect on getting vaccinated against both types of viruses, and an opposite effect on getting vaccinated only against seasonal influenza (demonstrated by a fairly high odds ratio). Regarding pandemic vaccination, these results are in line with the study by Bouadma and colleagues , who found that the choices to take vaccines are self-centred sociocognitive dimensions, such as the self-perception of benefits of the recommended preventive health action and health motivation (i.e., the opinion regarding the likelihood of the vaccine to preserve health).
Therefore, we can conclude that the following reasons are the most important predictors for getting the vaccine: ‘awareness of vaccine safety and side effects’, regarding the pandemic influenza vaccine, or the assertion that the vaccination is a safe practice, or thinking that a sufficient amount of information has been gathered regarding the usefulness of the vaccine. A recent review  regarding the influenza vaccine and HCWs also found that the lack of knowledge, or wrong beliefs in the efficacy of the vaccine and fear of side effects, could be determining factors in making the choice to get the influenza vaccine, or not.
For these reasons, it seems necessary that public health institutions that plan the information campaigns on vaccinations take these factors into consideration, especially if a new type of vaccine should be administered to the HCWs. Some authors  suggest that for this kind of campaign to be effective, it should be based on strategies of education and promotion of vaccination, as well as on easier access to the vaccine. Our results are in line with what is stated above; they suggest, in addition, that this kind of campaign should also be focused on the involvement of HCW participation in order to be effective and increase vaccination rates. The mere exposure to information, without assimilation within a personal set of knowledge and beliefs, is not sufficient.
These strategies could be more effective for HCWs with respect to other workers or persons because of their greater awareness of health topics. HCWs could benefit from specific training, with more detailed and comprehensive information regarding both the usefulness and the side effects of vaccinations. In literature, we could find some models that could help build an understanding of how to design effective campaigns or trainings. For example, in a recent study of Prati, Pietrantoni and Zani , the Extended Parallel Process Model (EPPM)  was analysed to better understand the persuasive messages concerning the influenza vaccination. This theory claims that fear appeals are likely to produce threat appraisal, and the appraisal of efficacy of the recommended response and self-efficacy. In addition to this, the theory postulates that high threats elicit negative emotions that, in turn, lead people to begin the efficacy appraisal. According to this, if the threat is perceived as low, people are not motivated enough to appraise the message and the efficacy. The results of this study show that narrative communication (e.g., use of anecdotes, testimonials, and stories) constitutes a more comprehensible and believable pedagogical communication. The authors found no relationship with the intention to vaccine, but this is likely due to the fact that the study was based on a telephone survey, and not a ‘real’ setting. Although the study was conducted with a sample of older people (more than 65), it is the first one that used the EPPM model to analyse the efficacy of messages to promote influenza vaccination.
Some limitations of this study have to be acknowledged. First of all, the sample is quite small, so future research should consider a larger number of workers involved in the study. In addition, we should also consider the fact that both scales have a limited number of items. Furthermore, the sample of our study were recruited at the vaccination/biological risk clinic, and this could produce bias.
Moreover, future research is needed about the efficacy of interventions aimed at improving vaccine-taking behaviour. This could be helpful for an in-depth analysis of the reasons that lead to take, or not take, the vaccine, and also in terms of excessive time and money consumption reasons.