Driving delivery and uptake of catch-up vaccination among adolescent and adult migrants in UK general practice: a mixed methods pilot study
Authors: Crawshaw Alison F. , Goldsmith Lucy P. , Deal Anna , Carter Jessica , Knights Felicity , Seedat Farah , Lau Karen , Hayward Sally E. , Yong Joanna , Fyle Desiree , Aspray Nathaniel , Iwami Michiyo , Ciftci Yusuf , Wurie Fatima , Majeed Azeem , Forster Alice S. , Hargreaves Sally 
Published: May 2024

Abstract
Background
Migrants in the UK and Europe face vulnerability to vaccine-preventable diseases (VPDs) due to missed childhood vaccines and doses and marginalisation from health systems. Ensuring migrants receive catch-up vaccinations, including MMR, Td/IPV, MenACWY, and HPV, is essential to align them with UK and European vaccination schedules and ultimately reduce morbidity and mortality. However, recent evidence highlights poor awareness and implementation of catch-up vaccination guidelines by UK primary care staff, requiring novel approaches to strengthen the primary care pathway.

Methods
The ‘Vacc on Track’ study (May 2021–September 2022) aimed to measure under-vaccination rates among migrants in UK primary care and establish new referral pathways for catch-up vaccination. Participants included migrants aged 16 or older, born outside of Western Europe, North America, Australia, or New Zealand, in two London boroughs. Quantitative data on vaccination history, referral, uptake, and sociodemographic factors were collected, with practice nurses prompted to deliver catch-up vaccinations following UK guidelines. Focus group discussions and in-depth interviews with staff and migrants explored views on delivering catch-up vaccination, including barriers, facilitators, and opportunities. Data were analysed using STATA12 and NVivo 12.

Results
Results from 57 migrants presenting to study sites from 18 countries (mean age 41 [SD 7.2] years; 62% female; mean 11.3 [SD 9.1] years in UK) over a minimum of 6 months of follow-up revealed significant catch-up vaccination needs, particularly for MMR (49 [86%] required catch-up vaccination) and Td/IPV (50 [88%]). Fifty-three (93%) participants were referred for any catch-up vaccination, but completion of courses was low (6 [12%] for Td/IPV and 33 [64%] for MMR), suggesting individual and systemic barriers. Qualitative in-depth interviews (n = 39) with adult migrants highlighted the lack of systems currently in place in the UK to offer catch-up vaccination to migrants on arrival and the need for health-care provider skills and knowledge of catch-up vaccination to be improved. Focus group discussions and interviews with practice staff (n = 32) identified limited appointment/follow-up time, staff knowledge gaps, inadequate engagement routes, and low incentivisation as challenges that will need to be addressed. However, they underscored the potential of staff champions, trust-building mechanisms, and community-based approaches to strengthen catch-up vaccination uptake among migrants.

Conclusions
Given the significant catch-up vaccination needs of migrants in our sample, and the current barriers to driving uptake identified, our findings suggest it will be important to explore this public health issue further, potentially through a larger study or trial. Strengthening existing pathways, staff capacity and knowledge in primary care, alongside implementing new strategies centred on cultural competence and building trust with migrant communities will be important focus areas.