Page 114 - Preventing pertussis in early infancy - Visser

Chapter 7
Chapter 7
Overarching themes: experience, information and trust
Experience
Experiences were mentioned often in the qualitative study and were diverse, including experiences with pertussis in the participants themselves or in their environment, and experiences with previously administered vaccinations or vaccination offers. They were used to explain and sometimes defend a certain belief or attitude towards vaccination. As such they seemed to influence the respondents’ perceived risks, their general vaccination beliefs (including trust), their feelings on autonomy and decisional uncertainty. In chapter 3 we described for example how maternity assistants experienced a previous vaccination offer as very imposing. This led them to emphasise the importance of autonomy in vaccination decisions and resulted in a strong opposition towards mandatory vaccination.
Both our quantitative studies (chapters 4 and 5) were not able to confirm a clear association between previous experiences and intention to accept a vaccination. In the univariate analyses among all HCW groups, previous acceptance of influenza vaccination was significantly associated with a positive intention towards pertussis cocooning vaccination. But only in midwives this association remained significant in the multivariate analysis. Multiple other studies did describe associations between previous vaccination acceptance (for instance for influenza) and present pertussis cocooning vaccination acceptance (Top et al. 2010, Bodeker et al. 2014, Lu et al. 2014, Tuckerman et al. 2015). In literature, the lack of experience with vaccine preventable diseases is often associated with a lower perceived risk of these diseases. As such it contributes to the occurrence of the well-known omission bias, where the risk of the commission of an action (vaccination) is perceived higher as the risk of the omission of an action (the disease), leading to lower uptake rates (Asch et al. 1994, Wroe et al. 2005, Bish et al. 2011). In this sense, experience is very similar to the term complacency, which is used in the vaccine hesitancy definition (MacDonald et al. 2015). Negative previous experiences have also been associated with less trust in vaccines (Larson et al. 2011).
Experience in intervention development
Although we found no direct quantitative evidence for the influence of previous experiences on vaccination acceptance in the quantitative studies, the indication of its influence from the qualitative studies and literature led us to take the theme into account in our final programme in two ways. First, we used peer models to elaborate on the experiences with pertussis in adults and in children, on the website and in the online deliberation tool. This aims to substitute the lack of personal experience people have with pertussis in adults and children. Second, previous experiences have influenced our view on the mandatory versus voluntary vaccination debate as described in chapter 3. The experience of respondents who were quite forcefully demanded by their employers to be vaccinated against influenza during the H1N1 pandemic, led us to better understand the potential detrimental effect of mandatory vaccination on the support for future vaccinations. This means that we believe that negative experiences (e.g. mandatory
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