Global migration has steadily risen, with 16% of the UK population born abroad. Migrants (defined here as foreign-born individuals) face unique health risks, including potential higher rates and delays in diagnosis of infectious and non-communicable diseases, compounded by significant barriers to healthcare. UK Public Health guidelines recommend screening at-risk migrants, but primary care often faces significant challenges in achieving this, exacerbating health disparities. The Health Catch-UP! tool was developed as a novel digital, multidisease screening and catch-up vaccination solution to support primary care to identify at-risk adult migrants and offer individualised care. The tool has been shown to be acceptable and feasible and to increase migrant health screening in previous studies, but to facilitate use in routine care requires the development of an implementation package. This protocol describes the development and optimisation of an implementation package for Health Catch-UP! following the person-based approach (PBA), a participatory intervention development methodology, and evaluates our use of this methodological approach for migrant participants.

Through engagement with both migrants and primary healthcare professionals (approximately 80–100 participants) via participatory workshops, focus groups and think-aloud interviews, the study aims to cocreate a comprehensive Health Catch-UP! implementation package. This package will encompass healthcare professional support materials, patient resources and potential Health Catch-UP! care pathways (delivery models), developed through iterative refinement based on user feedback and behavioural theory. The study will involve three linked phases (1) planning: formation of an academic–community coalition and cocreation of guiding principles, logic model and intervention planning table, (2) intervention development: focus groups and participatory workshops to coproduce prototype implementation materials and (3) intervention optimisation: think-aloud interviews to iteratively refine the final implementation package. An embedded mixed-methods evaluation of how we used the PBA will allow shared learning from the use of this methodology within the migrant health context.

Ethics approval granted by the St George’s University Research Ethics Committee (REC reference: 2024.0191). A community celebration event will be held to recognise contributions and to demonstrate impact.

To determine the independent predictors of full immunisation coverage (FIC) among children aged 12–23 months along with the parental awareness and attitudes (of children aged ≤23 months) regarding routine childhood vaccinations in Perambalur district of Tamil Nadu, South India.

A community-based cross-sectional analysis.

Perambalur district situated in the central region of Tamil Nadu state, South India.

Parents of children aged ≤23 months.

The primary outcome measured was the FIC and FIC plus in the district along with the parental awareness and attitudes regarding routine childhood vaccinations. The independent predictors of FIC and FIC plus were determined using multivariable logistic regression models.

The study included 652 children, with a mean (±SD) age of 16.47 (±6.37) months and a male-to-female ratio of 60:40. The FIC and FIC plus of children aged 12–23 months were 91.3% (95% CI 88.64 to 93.33) and 79.7% (95% CI 76.15 to 82.80), respectively. The immunisation card retention was 97.9% among the parents of children aged 12–23 months. The independent predictors of FIC included below poverty line families (adjusted OR (AOR) 0.11; 95% CI 0.02 to 0.64), illiteracy among mothers (AOR 0.67; 95% CI 0.32 to 0.87), lack of immunisation card (AOR 0.14; 95% CI 0.03 to 0.55), lack of frequent home visits by healthcare worker (AOR 0.38; 95% CI 0.18 to 0.79) and hesitancy of parents towards vaccination (AOR 0.26; 95% CI 0.12 to 0.87).

This study revealed a high FIC in this specific district. However, achieving full coverage is influenced by factors like socioeconomic status, maternal education and parental attitudes. Understanding these factors is essential for improving immunisation rates and ensuring all children are protected.