Leveraging state immunization information systems to measure the effectiveness of rotavirus vaccine.

OBJECTIVE: Electronic immunization information systems (IISs) are now established in almost all US states. We used the IIS in Minnesota, Georgia, and Connecticut for immunization data and as the source of 1 of 2 control groups to measure pentavalent rotavirus vaccine (RV5) effectiveness (VE) using case-control methodology. PATIENTS AND METHODS: Case-subjects were vaccine-eligible children who presented to 1 of 5 hospitals or emergency departments with gastroenteritis and had rotavirus antigen detected in stool during any of 3 rotavirus seasons (2007-2009). Two control groups were used: children with gastroenteritis who tested negative for rotavirus and children from the IIS matched by zip code and birth date. In Minnesota and Georgia, immunization records for rotavirus-positive and -negative children were also obtained from providers. RESULTS: Overall, 402 (96%) rotavirus case-subjects and 825 (97%) rotavirus-negative controls who met eligibility criteria were found in the IISs. Ten IIS controls were identified for each case. VE estimates for RV5 were similar across control groups, immunization data sources, and states. VE point estimates for 3 vs 0 doses were 89% to 94% among children aged 8 months or older and 86% to 92% among those aged 24 months or older. VE for 2 doses was ≥90% among children aged 8 months or older, and VE for 1 dose was 66% among those aged 6 weeks through 5 months. CONCLUSIONS: Three RV5 doses confer sustained protection against rotavirus disease during the first 3 years of life in US children. Two RV5 doses also seem to provide good protection. IISs can be valuable tools for assessing the effectiveness of vaccines administered to young children.

Up-to-date Haemophilus influenzae type b vaccination coverage during a vaccine shortage.

OBJECTIVES: We sought to assess Haemophilus influenzae type b (Hib) vaccination coverage in diverse areas of the United States during the 2008-2009 Hib vaccine shortage. Interim recommendations for Hib vaccination during the shortage called for deferral of the booster dose only among children not at high risk for disease; the primary series given during the first year of life continued to be recommended for all children. METHODS: Vaccination data on ∼123,000 children were collected from 8 Immunization Information System (IIS) sentinel sites. Completion of the primary Hib series (with 2 or 3 doses depending on vaccine type) by 9 months old during the vaccine shortage was compared with coverage of 2 vaccines given at similar ages (7-valent pneumococcal conjugate vaccine and diphtheria, tetanus acellular pertussis vaccine) in children born between November 1, 2007, and March 31, 2008. RESULTS: During the shortage period, Hib vaccination coverage for the primary series was 7.8 to 10.3 percentage points lower than diphtheria, tetanus acellular pertussis vaccine and 7-valent pneumococcal conjugate vaccine coverage for children by the age of 9 months in 7 of 8 sentinel sites. CONCLUSIONS: A significant decrease in Hib vaccination coverage for the primary series was observed and was consistent across several US localities. Close collaboration between the public health community and vaccine providers is essential during vaccine shortages to ensure that interim vaccination recommendations are clear, widely disseminated, and closely followed, and that access to available vaccine supplies is maintained.

Evaluating hepatitis B universal birth dose vaccination at Minnesota birthing hospitals by utilizing immunization information systems, birth certificates, and chart reviews, 2007-2008.

OBJECTIVES: The Minnesota Department of Health (MDH) examined hospital practices as recommended by the Advisory Committee on Immunization Practice in 2005 that hepatitis B vaccine should be administered universally to newborn infants prior to hospital discharge and within 12 hours of birth if their mothers test positive or are admitted with unknown status for hepatitis B surface antigen. METHODS: The MDH conducted a survey of perinatal hepatitis B birth dosing policies in Minnesota birthing hospitals, which prompted (1) and investigation of hospital birth dose rates from the Immunization Information System (IIS) and (2) a chart review of three selected hospitals with low rates. RESULTS: The (IIS) records of children born in Minnesota during 2007 and the first 5 months of 2008 showed a hepatitis B birth dose rate that was lower than expected (2007: 37%; 2008: 48%). The chart review of three hospitals with low birth does rates showed rates for the first 6 months of 2008 of 94%, 89%, and 91% compared with IIS rates of 1.4%, 40%, and 39% respectively, during the same time period. CONCLUSIONS: These results prompted MDH to increase efforts to provide education to birth registrars on the importance of hepatitis B vaccine data on the birth certificate and to promote regular transmission of hospital vaccination data to the IIS.