As fewer children are immunised, so herd immunity (whereby a sufficient proportion of immunised people inhibits disease transmission in a population [23]) is compromised, and people who are not protected (including those who cannot

be immunised for medical reasons) are placed at increased risk of these infections. Outbreaks, particularly of measles, have been recently reported in Europe [24] and the US [25]. There are concerns that the developed world may export measles to developing countries where the infection poses a greater Onalespib chemical structure risk to health and a greater drain on already scant resources [26]. As measles incidence increases, time passes since the height of the MMR-autism controversy, and the media

becomes increasingly critical of the paper which sparked the controversy [27], it is perhaps no surprise that MMR uptake is improving. Chen’s model of natural fluctuations in vaccine uptake [28] indicates an oscillation whereby as vaccine uptake decreases, disease increases – so in response to this increased disease threat, vaccine uptake increases. By understanding exactly what is changing in parents’ decision-making and harnessing or tapping into those changes, we may expedite this ‘natural’ upturn and more effectively manage any new misconceptions. Qualitative approaches may provide more scope than quantitative population surveys to explore nuanced and novel decision influences, as they allow parents to describe their decision processes without the boundaries set or implied GS-7340 clinical trial by predefined survey questions.

Previously, qualitative studies of MMR decision-making have identified several themes salient to parents which quantitative work had failed to investigate, highlighting the distinct Resminostat benefits of this approach [10]. In the UK, parents’ MMR decisions have rarely been explored using detailed qualitative methods since uptake of the vaccine started to improve after its lowest point in 2004 [18], and many studies have methodological shortcomings [10]. Ideally, prospective rather than retrospective interviews [29] and [30] should be used to eliminate the risk of consistency bias [31] in which thoughts which were part of the process but which do not fit with the eventual decision are ‘edited out’ of the memory. Further, outcome measures should be drawn from objective official vaccine records rather parental report [9] and [32] to eliminate the possible margin of error around parents’ memory of, awareness of, and willingness to be open about whether and when their child was vaccinated [33], [34] and [35]. Finally, analytic bias [36] should be countered by having more than one analyst work on the data [9], [29] and [30] and employing a “member check” with research participants to ensure that they agree with the interpretation of their interview [37].