Racial, Ethnic, and Sociodemographic Disparities in the Uptake of the MMR Vaccine Among Minnesota Children.

The US has seen a sharp increase in measles cases in recent years. The measles vaccines (MMR and MMRV) are highly effective at preventing measles infections; however, vaccine coverage varies between racial/ethnic categories. Our objective was to use Minnesota Department of Health data to examine the association between a child's birthing parent's race, ethnicity, and other sociodemographic characteristics, and receipt of the first dose of a measles-containing vaccine by age 24 months. Sociodemographic data came from Minnesota birth certificate records (from 2017 to 2022), which are unique among states in how detailed ethnicity is characterized. During this timeframe, only 80% of the study population received the first dose of a measles-containing vaccine by age 24 months. We identified vaccination inequities by ethnicity, which could not be fully explained by these ethnic groups' differing socioeconomic status. Two groups, Somali-Minnesotan and Ethiopian-Minnesotan (which are often aggregated into a "Black" race), had the lowest levels of on-time first dose coverage (Somali = 31%, Ethiopian = 64%). Other factors associated with a lower predicted probability of coverage by 24 months included receiving inadequate prenatal care and lower socioeconomic status. Our main findings demonstrate the importance of racial/ethnic disaggregation when studying vaccine inequities. Collapsing race/ethnicity into broad categories like "Black" or "Hispanic" obscures a great deal of variability in outcomes. Those who are identified as at-risk for missing vaccine doses, the causes for this, and the possible approaches public health agencies might consider in preventing outbreaks should all differ depending on who is most affected.