The following section presents a brief summary of similarities between immunisers and non-immunisers in terms of the concepts in the Health Belief Model. This is followed by a critical interpretation of the data linking this model with the theories of subjective perception of risk and decision-making under uncertainty. Finally the differences found between complete, incomplete, partial and nonimmunisers in terms of these theories are summarised. Table 2 summarises the differences and similarities between complete, incomplete and non-immunisers in terms of the core concepts of the Health Belief Model from these interviews (see [16] for further details). Partial immunisers formed two groups; those whose child had had a severe reaction to DTP (Diphtheria, Tetanus, Pertussis vaccine) (n = 3) where the parents had been advised not to continue with vaccination and those who chose to only undertake some vaccinations or changed their mind about vaccinations after the first DTP vaccine (n = 4). The former of these expressed views similar to complete immunisers and the latter to nonimmunisers. To better understand these differences in perceptions, the interviews were analysed firstly for themes from the studies of risk perception-dread, familiarity and controllability.