Our analysis of health locus of control data found that those never vaccinated had a lowest 'powerful others ' locus of control for their vaccination behaviours, indicating that they did not believe their health was something over which they had no control [32] . This pattern of health beliefs towards influenza vaccination is consistent with their low-risk perception of personal vulnerability to illness and 'no need ' as their reason refusing vaccination and may be an important factor for never vaccinated nurses. Further studies are needed to explore what may influence this pattern of health locus of control in order to modify nurses' vaccination behaviours.