Discussion

1
Results
Conclusions
Background

• 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 6 - 15 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
• lt 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

• 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 RV51
• 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 2010. 3 Staat, et
  al. Effectiveness of Pentavalent Rotavirus
  Vaccine Against Severe Disease, Pediatrics 2011.
• 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 using IIS
data
Multivariate Results
Table 2. Maternal risk factors among 'partial' and 'no RV5' coverage groups compared to 'full' coverage groupN 62,597 matched records from 2010 birth cohort Table 2. Maternal risk factors among 'partial' and 'no RV5' coverage groups compared to 'full' coverage groupN 62,597 matched records from 2010 birth cohort Table 2. Maternal risk factors among 'partial' and 'no RV5' coverage groups compared to 'full' coverage groupN 62,597 matched records from 2010 birth cohort Table 2. Maternal risk factors among 'partial' and 'no RV5' coverage groups compared to 'full' coverage groupN 62,597 matched records from 2010 birth cohort
    Partial Coverage No RV5
Predictor Category Adjusted OR (95 CI) Adjusted OR (95 CI)
Age lt20 2.1 (1.85, 2.45) 1.4 (1.17, 1.78)
  20-29 1.5 (1.36 1.72) 1.0 (0.82, 1.12)
  30-39 1.1 (0.96, 1.2) 0.9 (0.74, 0.99)
  40-54 Reference Reference
Race AI/AN 1.5 (1.29, 1.65) 1.7 (1.45, 2.04)
  Asian 0.9 (0.86, 1.02) 0.4 (0.37, 0.50)
  Black 1.3 (1.20, 1.41) 0.5 (0.43, 0.60)
  Hisp/Latino 0.8 (0.70, 0.81) 0.4 (0.31, 0.41)
  Pac Islander 1.2 (1.06, 1.31) 0.6 (0.49, 0.74)
  White Reference Reference
Primiparous Primiparous 0.8 (0.74, 0.84) 0.9 (0.79, 0.94)
Previous live births Previous live births 1.2 (1.18, 1.24) 1.2 (1.14, 1.22)
Education High school 1.7 (1.63, 1.86) 1.1 (0.99, 1.19)
  Some college 1.6 (1.46, 1.65) 1.2 (1.11, 1.31)
  College Reference Reference
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)
Dose 1 Dose 2 Dose 3
2 months 4 months 6 months
Max 14 wks, 6 days Max 8 mo, 0 days
1 http//www.cdc.gov/vaccines/recs/schedules/ 1 http//www.cdc.gov/vaccines/recs/schedules/ 1 http//www.cdc.gov/vaccines/recs/schedules/
outcomes of interest reference group

Univariate Comparisons
Table 1. Maternal risk factors expressed as proportions among coverage groups N 62,597 matched records from 2010 birth cohort Table 1. Maternal risk factors expressed as proportions among coverage groups N 62,597 matched records from 2010 birth cohort Table 1. Maternal risk factors expressed as proportions among coverage groups N 62,597 matched records from 2010 birth cohort Table 1. Maternal risk factors expressed as proportions among coverage groups N 62,597 matched records from 2010 birth cohort Table 1. Maternal risk factors expressed as proportions among coverage groups N 62,597 matched records from 2010 birth cohort
Predictor Category Full Coverage n44,167 Partial Coverage n13,431 No RV5 n4,999
Age lt20 4.8 7.3 5.2
  20-29 47.4 55.7 47.3
  30-39 43.9 33.9 42.6
  40-54 4 3.1 4.9
Race AI/AN 1.6 3.4 3.6
  Asian 8.6 5.3 3.8
  Black 4.8 7.6 3
  Hisp/Latino 10.8 11.5 5.1
  Pac. Islander 3.1 3.9 2.2
  White 71.1 68.4 82.4
Primiparous Primiparous 46.4 35.1 36.9
Previous live births Previous live births 0.9 1.3 1.2
Education High school 30.5 50.9 36.8
  Some college 29.7 31.6 34.3
  4yr College 33.5 17.5 29.3
Married   68.4 57.8 71.1
Medicaid   36.3 49 36.9
Objective
Limitations
Methods
Odds for partial coverage and no RV5 increased
by 20 with each previous birth / older sibling
Rotavirus vaccine coverage among 2010 birth
cohort by county, WA State
Full Coverage Three doses RV5 by 8 months
Partial Coverage One or two dose(s) RV5
No RV5 No RV5 dose (but one other dose between 6 - 15 weeks)
No Vaccine No vaccine dose (any) between 6 - 15 weeks
Acknowledgements
Kathleen Stigi, MPH Epidemiologist Katie.Stigi_at_doh.wa.gov [phone] 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 5U38HM000414
P-value lt 0.05 when compared to full
coverage group Continuous variable mean
expressed