A new study led by researchers at St Mary’s University, London, has revealed that mistrust, misinformation and a lack of culturally tailored communication are key reasons why some adults aged 50 and over continue to decline the COVID vaccine booster doses – particularly within ethnically diverse and socioeconomic disadvantaged populations.
The research, known as the TRUST Study, highlights that vaccine hesitancy is rarely driven by a single concern. Instead, it reflects a complex mix of psychology, social and practical factors that influence how people engage with public messaging. The study aimed to bridge the gap by improving the effectiveness of future booster dose campaigns targeting specific audiences.
The qualitative study involved in-depth online interviews with 30 adults aged over 50 in London and the West Midlands who had declined a COVID-19 booster dose. Participants discussed their attitudes towards vaccines and their experience of health information and misinformation.
Four key themes were found from analysing the research:
- Vaccine production and administration, including mistrust in vaccine manufacturing
- Health misinformation and beliefs, influenced by social networks
- Personal circumstances and social influences including trust in healthcare systems
- Policy and logistics factors, such as access to appointments and clear guidance
The research found that mistrust was often not limited to vaccines themselves, but reflected broader concerns about health systems, communication and feeling unheard.
Samual Lam, Research Fellow in the School of Allied Health and Life Science at St Mary’s University, said: “Our findings show that vaccine hesitancy is not simply lack of information. Many participants described feeling excluded from public health conversations or unsure whether messaging reflected their lived experience. Building trust requires listening, transparency, and communication that speaks to different communities in meaningful ways.
This research show that there are implications beyond Covid 19 offering valuable lesson for future public initiatives, including flu vaccination campaigns and other booster programmes.”
Dr Silvia Riva, Associate Professor in Psychology at St Mary’s University and Principal Investigator of the study, explained that "Mistrust is influenced by cultural practices and the knowledge schemas through which individuals interpret scientific information. In many cultural contexts, science is commonly understood as a gradual process involving time, trials, and errors. The unusually rapid development of vaccines, while representing a remarkable scientific achievement, may therefore have challenged these expectations and contributed to concerns about trust and reliability among some individuals."
The TRUST Study was funded by unconditional research grant from Moderna, enabling St Mary’s researchers to collaborate with industry while maintaining academic independence and a focus on public insight and health equity.
The full study, Barriers to equitable COVID-19 booster uptake among adults aged 50 and older in the UK: psychological factors and misinformation influencing vaccine hesitancy has been published.
Watch Inside St Mary's: Understanding Vaccine Hesitancy