The effectiveness of immunization is widely accepted: it can successfully improve health outcomes by reducing the morbidity and mortality associated with vaccine-preventable diseases. In the era of pandemics, there is a pressing need to identify and understand the factors associated with vaccine uptake amongst different socioeconomic groups. The knowledge generated from research in this area can be used to inform effective interventions aimed at increasing uptake. This umbrella systematic review aims to determine whether there is an association between socioeconomic inequalities and rate of vaccine uptake globally. Specifically, the study aims to determine whether an individual's socioeconomic status, level of education, occupation, (un)-employment, or place of residence affects the uptake rate of routine vaccines. The following databases will be searched from 2011 to the present day: Medline (Ovid), Embase (Ovid), CINAHL (EBSCO), Cochrane CENTRAL, Science Citation Index (Web of Science), DARE, SCOPUS (Elsevier), and ASSIA (ProQuest). Systematic reviews will be either included or excluded based on a priori established eligibility criteria. The relevant data will then be extracted, quality appraised, and narratively synthesised. The synthesis will be guided by the theoretical framework developed for this review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Equity extension (PRISMA-E) guidance will be followed. This protocol has been registered on PROSPERO, ID: CRD42022334223.
Keywords: evidence synthesis; routine vaccinations; socioeconomic inequalities; vaccine uptake.