Routine early childhood vaccination uptake before and during the COVID-19 pandemic in Scotland: A population-based cohort study of administrative data.

OBJECTIVES: The COVID-19 pandemic changed the working patterns of many families and led to an increased focus on vaccines. This may have influenced early childhood vaccination uptake. We utilised linked administrative health data for Scotland to investigate whether the pandemic was associated with changes in uptake of early childhood vaccinations. STUDY DESIGN: Retrospective observational cohort design examining population-based individual-level linked administrative health data for Scotland. METHODS: We assessed timely uptake of six routine vaccinations - 6-in-1 vaccine, pneumococcal conjugate vaccine (PCV), rotavirus vaccine, Hib/MenC vaccine, measles, mumps and rubella (MMR) vaccine and PCV booster - among children reaching 12 months or 24 months of age in Scotland, January 2019-December 2021 (N = 199,574 children). Logistic regression modelling assessed uptake among a pandemic cohort compared to a pre-pandemic cohort, with and without adjustment for key sociodemographic variables. Interaction analysis assessed whether associations varied across area deprivation, parental socioeconomic class, urban-rural residence, and maternal ethnic group. RESULTS: Vaccination uptake either remained stable or increased for five of the six vaccines during the pandemic. Most interactions were not statistically significant, indicating broadly similar pandemic effects across sociodemographic groups. However, large pre-existing inequalities remained during the pandemic, with least-deprived areas and managerial/professional households having higher uptake, and several minority ethnic groups having lower uptake. CONCLUSIONS: Scotland's childhood immunisation programme showed resilience during the pandemic, but pre-existing inequalities persisted. Future planning should include safeguarding early-life vaccines and addressing structural barriers.