Timely Prenatal and Infant Pertussis Vaccine Uptake in an Integrated Health System

Background Hispanic infants bear the burden of pertussis infection. We examined pertussis protection from vaccination in infants with US-born and foreign-born Hispanic mothers. Methods Retrospective cohort study of infants up to 1 year of age. Secondary data of mothers with continuous membership since the 27th week of pregnancy with infants born 1/1/2012–12/31/2017 in an integrated health care delivery organization, which broadly represent the Southern California population. Results Foreign-born Hispanic mothers had higher prenatal tetanus, diphtheria, acellular pertussis (Tdap) uptake compared to US-born white mothers [adjusted risk ratio (aRR): 1.04, 95% confidence interval (CI): 1.03, 1.05]. Infants with mothers on Medicaid insurance disproportionately did not enroll in the health plan by the time they were eligible for their first dose of the DTaP vaccine (68.4%). Once initiating the infant vaccine series, foreign-born Hispanic mothers more likely adhered than US-born white mothers (aRR: 1.05, CI: 1.02, 1.08). Discussion In an integrated health system, disparities in vaccine uptake can be minimized. Infants who are born to mothers with Medicaid insurance and are not enrolled in the health plan after birth may be under-protected from pertussis.