Since 2013 uptake of the combined measles mumps and rubella (MMR) vaccine has declined in children in England year upon year. This has resulted in an increase in the number of measles cases, leading the World Health Organization to withdraw the UKs measles elimination status in 2019. The reasons for the decline in MMR uptake are unclear. Public Health England publishes figures on regional variation and the National Audit Office publishes rates by area socioeconomic deprivation (a measure of the level of poverty in an area). But no information is available on rates by other area based measures nor by maternal characteristics such as age, ethnicity, or the number of children a mother has. NHS England and Public Health England have identified several contributing factors, including problems with access, anti-vaccination messages, and parental vaccine hesitancy. The objective of this study is to explore individual and area level factors associated with likelihood of MMR immunisation, and furthermore to establish whether the main reasons for low vaccine uptake are limited access (i.e. GP practice/regional level variation) or individual differences in vaccine acceptance (i.e. variation at the maternal level). The expected public health benefit of this research is the ability to target areas or groups of mothers with low access, or mothers with characteristics associated with lower acceptance, with the ultimate aim of increasing MMR uptake.
This study aims to explore potential predictors of low MMR vaccine uptake. Predictors fit broadly into three categories: area level exposures; maternal characteristics; and pregnancy history/current pregnancy factors. The CPRD Gold data will be used to establish a cohort of women in the pregnancy register whose pregnancies resulted in live births. Area-based socioeconomic status will be assessed based on the linked small-area data (English Index of Multiple Deprivation). Practice (including Up To Standard date), region, urban/rural classification, mothers age, ethnicity, religion, number of children attached to the mother, parity, number of miscarriages, previous infant deaths, childs gender, pre(eclampsia), pregnancy hypertension, gestational diabetes, preterm delivery, and maternal history of anxiety or depression will be extracted from the primary care data. The outcome variables will be MMR1 at 24 months, MMR1 at 5 years, and MMR2 at 5 years. Vaccinated and unvaccinated children will be compared on predictor variables univariately, using two sample t-tests for quantitative variables and chi-square analysis for qualitative variables. Formal analysis will comprise multiple regression. As sensitivity analyses, the primary analysis will be replicated: 1. with the outcome the 5-in-1 combined diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b vaccine (DTaP/IPV/Hib) at 12 months, 24 months and 5 years; and the outcome the combined Haemophilus influenzae type b and meningococcal group C vaccine (Hib/MenC) at 24 months and 5 years; 2. in the subset of practices that are not Up To Standard.
MMR1 at 24 months; MMR1 at 5 years; and MMR2 at 5 years.
Claire Hastie - Chief Investigator - University of Glasgow
Claire Hastie - Corresponding Applicant - University of Glasgow
Daniel Mackay - Collaborator - University of Glasgow
Janeth Doji Haruna - Collaborator - University of Glasgow
Jill Pell - Collaborator - University of Glasgow
Paul Welsh - Collaborator - University of Glasgow
Qianqian Jiang - Collaborator - University of Glasgow
2011 Rural-Urban Classification at LSOA level;CPRD Mother-Baby Link;Patient Level Index of Multiple Deprivation;Pregnancy Register