Rotavirus vaccine coverage among a 2010 birth cohort and risk factors for partial or no coverage, Washington State 2010 K. Stigi, C. DeBolt, K. Lofy Washington State Department of Health – Office of Communicable Disease Epidemiology Discussion Rotavirus vaccine coverage estimates for WA using IIS data higher than NIS coverage estimates Partial coverage known to confer substantial immunity, suggesting that 80.6% of 2010 birth cohort achieved some immunity despite only 60% achieving ‘full’ coverage Among those with no RV5 dose, nearly 40% received another vaccine between weeks of age; unclear whether vaccine was not offered or refused Rotavirus unique vaccine in that first dose must be administered by 15 weeks of age, otherwise series not initiated Coverage estimates highly variable among WA counties The following maternal characteristics strongly associated with 'partial' coverage: younger age; AI/AN, Black, or Pacific Islander race; multiparity; ≤ high school education or some college (compared to ≥ college degree); Medicaid use The following maternal characteristics strongly associated with ‘No RV5’: AI/AN race; married; multiparity; some college Consistent with previously described risk factors for delayed or no vaccine coverage, multiparity significantly associated with 'partial' and 'no RV5' groups; odds increase with each previous live birth Further studies needed to better understand reasons for no rotavirus vaccine coverage < 100% of WA vaccine providers participate in the WA IIS Since IIS initially populated with birth certificate data, unclear whether those with no immunization data refused all vaccines, see a provider who does not participate in IIS, or left the state Inactive records lack ‘date effective’ for inactivity, therefore unclear whether these patients were active through rotavirus vaccine time period so they were excluded Phyllis Reed 1, Belinda Baker 1, Janna Bardi 1, Sherry Riddick 2,Yousif Hozail 2, Wayne Turnberg 1, Natasha Close 1, Kathryn MacDonald 1, Tracy Sandifer 1, Erica Smith 3 1 Washington State Department of Health 2 Washington State Immunization Information System 3 Pennsylvania Department of Health National Immunization Survey (NIS) 2009 and 2010 estimates ranked WA State among lowest in nation for rotavirus coverage (20.9% and 50.4%, respectively) Prior to rotavirus vaccine introduction, one in 60 U.S. children were hospitalized for rotavirus by age 5 Vaccines For Children Program (VFC) provides free vaccine to all children ≤ 18 years in WA State and distributes the RotaTeq (RV5) rotavirus vaccine Recommended schedule for RV5 1 WA State Immunization Information System (IIS) is a secure web-based registry with 95% participation among vaccine providers, covering 98% of VFC doses Studies have found partial RV5 vaccination confers up to 85% protection (range: 69% - 85%) 2,3 2 Boom, et al. Effectiveness of Pentavalent Rotavirus Vaccine in a Large Urban Population in the United States, Pediatrics Staat, et al. Effectiveness of Pentavalent Rotavirus Vaccine Against Severe Disease, Pediatrics To estimate rotavirus vaccine coverage in WA State using IIS data, and to explore maternal characteristics associated with partial or no rotavirus coverage Rotavirus Vaccine Coverage Estimates IIS data extracted for all children born during 2010 (n=97,664) Records with no immunization data excluded (5,000) Inactive records excluded (5,202) Coverage groups assigned: Maternal Predictors For ‘Partial’ or ‘No’ Coverage IIS records linked to 2010 birth certificate data ‘No vaccine’ group excluded from analyses Dataset restricted to records with WA birth residence and complete data among variables of interest X 2 tests assessed univariate associations (Table 1) Odds ratios generated from multivariate model (Table 2) Analyses completed using SAS 9.3 and LinkPlus Objective Kathleen Stigi, MPH Epidemiologist (206) This study was supported in part by an appointment to the Applied Epidemiology Fellowship Program administered by the Council of State and Territorial Epidemiologists (CSTE) and funded by the Centers for Disease Control and Prevention (CDC) Cooperative Agreement Number 5U38HM Results Rotavirus vaccine coverage estimates using IIS data Dose 1Dose 2Dose 3 2 months4 months6 months Max: 14 wks, 6 daysMax: 8 mo, 0 days 1 / Rotavirus vaccine coverage among 2010 birth cohort by county, WA State Limitations Methods Conclusions 2010 Birth Cohort (WA IIS) N = 87,301 Rotavirus Dose n=70,350 (80.6) Full Coverage n=52,468 (60.1) Partial Coverage n=17,882 (20.5) No Rotavirus Dose n=16,951 (19.4) No RV5 n=6,678 (7.6) No Vaccine n=10,273 (11.8) * P-value < 0.05 when compared to ‘full’ coverage group + Continuous variable – mean expressed Full CoverageThree doses RV5 by 8 months Partial CoverageOne or two dose(s) RV5 No RV5No RV5 dose (but ≥ one other dose between weeks) No VaccineNo vaccine dose (any) between weeks = outcomes of interest = reference group Table 1. Maternal risk factors expressed as proportions among coverage groups N= 62,597 matched records from 2010 birth cohort PredictorCategory % Full Coverage n=44,167 % Partial Coverage n=13,431 % No RV5 n=4,999 Age< * * * *4.9* RaceAI/AN1.63.4*3.6* Asian8.65.3*3.8* Black4.87.6*3* Hisp/Latino *5.1* Pac. Islander3.13.9*2.2* White *82.4* Primiparous *36.9* Previous live births *1.2* Education≤ High school *36.8 Some college *34.3* ≥ 4yr College *29.3* Married *71.1* Medicaid *36.9 Table 2. Maternal risk factors among 'partial' and 'no RV5' coverage groups compared to 'full' coverage group N= 62,597 matched records from 2010 birth cohort Partial CoverageNo RV5 PredictorCategory Adjusted OR (95% CI) Adjusted OR (95% CI) Age<202.1 (1.85, 2.45)1.4 (1.17, 1.78) ( )1.0 (0.82, 1.12) (0.96, 1.2)0.9 (0.74, 0.99) 40-54Reference RaceAI/AN1.5 (1.29, 1.65)1.7 (1.45, 2.04) Asian0.9 (0.86, 1.02)0.4 (0.37, 0.50) Black1.3 (1.20, 1.41)0.5 (0.43, 0.60) Hisp/Latino0.8 (0.70, 0.81)0.4 (0.31, 0.41) Pac Islander1.2 (1.06, 1.31)0.6 (0.49, 0.74) WhiteReference Primiparous0.8 (0.74, 0.84)0.9 (0.79, 0.94) Previous live births*1.2 (1.18, 1.24)1.2 (1.14, 1.22) Education≤ High school1.7 (1.63, 1.86)1.1 (0.99, 1.19) Some college1.6 (1.46, 1.65)1.2 (1.11, 1.31) ≥ CollegeReference Married 0.9 (0.83, 0.92)1.2 (1.12, 1.31) Medicaid 1.1 (1.05, 1.16)1.1 (1.00, 1.17) Acknowledgements Background Univariate Comparisons Multivariate Results * Odds for partial coverage and no RV5 increased by 20% with each previous birth / older sibling