Abstract Background: Since 2016, large scale measles outbreaks have heavily affected countries across Europe. In England, laboratory confirmed measles cases increased almost four-fold between 2017 and 2018, from 259 to 966 cases. Several of the 2017-18 measles outbreaks in England particularly affected Romanian and Roma Romanian communities, with the first outbreaks in these communities occurring in Birmingham, Leeds and Liverpool. This study explored factors influencing vaccination behaviours amongst Romanian and Roma Romanian communities in these three cities. Methods: Across Birmingham, Leeds and Liverpool, we conducted semi-structured interviews with 33 key providers to explore their experience in delivering vaccinations and managing the outbreak response. We also interviewed 9 Romanian women in one of the cities to explore their vaccination attitudes and behaviours. To categorise factors affecting vaccination we applied the 5As Taxonomy for Determinants of Vaccine Uptake (Access, Affordability, Awareness, Acceptance and Activation) during data analysis. Findings: Factors related to access and acceptance, such as language and literacy, ease of registering with a general practice, and trust in health services, were reported as the main barriers to vaccination amongst the communities. Concerns around vaccination safety and importance were reported but these appeared to be less dominant contributing factors to vaccination uptake. The active decline of vaccinations amongst interviewed community members was linked to distrust in healthcare services, which were partly rooted in negative experiences of healthcare in Romania and the UK. Conclusion: Access and acceptance, dominant barriers to vaccination, can be improved through the building of trust with communities. To establish trust providers must find ways to connect with and develop a greater understanding of the communities they serve. To achieve this, cultural and linguistic barriers need to be addressed. Better provider-service user relationships are crucial to reducing vaccination inequalities and tackling broader disparities in health service access.