Determinants of adult influenza and tetanus vaccination in the UK

Abstract

Vaccination coverage in adults remains suboptimal. Health organisations have only recently begun to recognise the role of socio-psychological factors in vaccination decisions. These factors are particularly important, given that they are inherently amenable to policy and behaviour change. This thesis employs a mixed-methods approach to investigate the determinants of adult seasonal influenza and tetanus vaccination in the UK general adult population. It focuses on socio-psychological factors and draws upon health behaviour models, heuristics and biases and customer journey mapping theoretical approaches to guide research and elucidate findings. A narrative and a systematic review and meta-analysis reveal there are a number of socio-psychological factors frequently associated with vaccination, particularly influenza and influenza vaccine risk perception, perceived vaccine effectiveness and reported physician recommendation, and show that most of the evidence in this area is produced in the US. They also highlight the importance of some vaccine risk perceptions, such as influenza-like symptoms and unspecific side-effects, and demonstrate that the existing evidence is highly heterogeneous and often lacking in quality, further supporting a case for robust empirical research on this topic. Two qualitative studies show that vaccine uptake is largely driven by people’s risk perception of influenza and tetanus, and that the tetanus vaccine is perceived as safe, unlike the influenza vaccine. They also reveal how specific healthcare ‘touchpoints’ across the immunisation journey can facilitate or hinder uptake. A novel finding is that certain childhood experiences can influence adult vaccination decisions. Two cross-sectional survey studies show that a compact set of variables can predict 91% of influenza and 75% of tetanus vaccination behaviour. They also demonstrate that socio-psychological factors are the most important determinants of vaccination behaviour. This thesis shows that incorporating socio-psychological dimensions in all aspect of immunisation policy, from surveillance systems to policy evaluation, is critical to improve vaccination rates.