Pertussis and Influenza Vaccination Among Insured Pregnant Women ­ Wisconsin, 2013-2014.

On February 22, 2013, the Advisory Committee on Immunization Practices (ACIP) revised recommendations for vaccination of pregnant women to recommend tetanus-diphtheria-acellular pertussis vaccine (Tdap) during every pregnancy, optimally at 27-36 weeks of gestation, to prevent pertussis among their newborns. Since 2004, influenza vaccination has been recommended for pregnant women in any trimester to prevent influenza and associated complications for mother and newborn. To evaluate vaccination of pregnant women in Wisconsin after the 2013 Tdap recommendation, health insurance claims data for approximately 49% of Wisconsin births were analyzed. The percentage of women who received Tdap during pregnancy increased from 13.8% of women delivering during January 2013 (63.1% of whom received Tdap 2-13 weeks before delivery) to 51.0% of women delivering during March 2014 (90.9% of whom received Tdap 2-13 weeks before delivery). Among women delivering during November 2013-March 2014, 49.4% had received influenza vaccine during pregnancy. After the 2013 recommendation, Tdap vaccination among pregnant women increased but plateaued at rates similar to influenza vaccination rates. Prenatal care providers should implement, evaluate, and improve Tdap and influenza vaccination programs, and strongly recommend that pregnant patients receive these vaccines to prevent severe illness and complications among mothers and infants.

Completeness and accuracy of the wisconsin immunization registry: an evaluation coinciding with the beginning of meaningful use.

CONTEXT: Vaccination coverage rates can be improved through the application of complete and accurate immunization information systems (IISs). OBJECTIVE: Evaluate the completeness and accuracy of Wisconsin's IIS, the Wisconsin Immunization Registry (WIR). DESIGN: Cross-sectional evaluation, comparing vaccination medical records (MRs) from provider clinics with WIR records. PARTICIPANTS: Medical records of patients born during 2009 were randomly selected from 251 Wisconsin clinics associated with the Vaccines for Children Program. MAIN OUTCOME MEASURES: Completeness: percentage of patients with client records in the WIR, percentage of patients up-to-date (%UTD) with the 4:3:1:3:3:1:4 vaccination series, and percentage of patients' MR vaccinations matched by administration date (±10 days) and type to vaccinations documented in the WIR. Accuracy: percentages of matched vaccinations with the same administration date, same trade name (TN), and same lot number. RESULTS: Of the 1863 selected patient MRs, 98% (n = 1833) had WIR client records and 97% of their 30 899 vaccinations were documented in the WIR. The %UTD was 49.3% using the MR only, 76.5% using the WIR only, and 75.2% as estimated by the National Immunization Survey. Among matched vaccinations, 99% had the same administration date, 96% had the same TN, and 95% had the same lot number. Compared with patients from clinics that entered data into the WIR using data exchange from electronic health records, patients from clinics that entered data using the Web-based user interface were less likely to have client records in the WIR (odds ratio: 0.3; 95% confidence interval: 0.1-0.9) and less likely to have accurate TNs (odds ratio: 0.3; 95% confidence interval: 0.1-0.5). CONCLUSIONS: The WIR was complete and accurate among this sample of children born during 2009 and provided a vaccination coverage assessment similar to the National Immunization Survey. Our results provide support for the expectation that meaningful use and other initiatives that increase data exchange from electronic health records to IISs will improve IIS data quality.

Estimating the effectiveness of tetanus-diphtheria-acellular pertussis vaccine (Tdap) for preventing pertussis: evidence of rapidly waning immunity and difference in effectiveness by Tdap brand.

BACKGROUND: We estimated the vaccine effectiveness (VE) of tetanus-diphtheria-acellular pertussis vaccine (Tdap) for preventing pertussis among adolescents during a statewide outbreak of pertussis in Wisconsin during 2012. METHODS: We used the population-based Wisconsin Immunization Registry (WIR) to construct a cohort of Wisconsin residents born during 1998-2000 and collect Tdap vaccination histories. Reports of laboratory-confirmed pertussis with onset during 2012 were matched to WIR clients. Incidence rate ratios (IRRs) of pertussis and Tdap VE estimates [(1 - IRR)*100%], by year of Tdap vaccine receipt and brand (Boostrix/Adacel), were estimated using Poisson regression. RESULTS: Tdap VE decreased with increasing time since receipt, with VEs of 75.3% (95% confidence interval [CI], 55.2%-86.5%) for receipt during 2012, 68.2% (95% CI, 60.9%-74.1%) for receipt during 2011, 34.5% (95% CI, 19.9%-46.4%) for receipt during 2010, and 11.9% (95% CI, -11.1% to 30.1%) for receipt during 2009/2008; point estimates were higher among Boostrix recipients than among Adacel recipients. Among Tdap recipients, increasing time since receipt was associated with increased risk, and receipt of Boostrix (vs Adacel) was associated with decreased risk of pertussis (adjusted IRR, 0.62 [95% CI, .52-.74]). CONCLUSIONS: Our results demonstrate waning immunity following vaccination with either Tdap brand. Boostrix was more effective than Adacel in preventing pertussis in our cohort, but these findings may not be generalizable to adolescent cohorts that received different diphtheria-tetanus-acellular pertussis vaccines (DTaP) during childhood and should be further examined in studies that include childhood DTaP history.

The Wisconsin immunization registry experience: comparing real-time and batched file submissions from health care providers.

CONTEXT: The Wisconsin Immunization Registry is a confidential, web-based system used since 1999 as a centralized repository of immunization information for Wisconsin residents. OBJECTIVE: Provide evidence based on Registry experiences with electronic data exchange, comparing the benefits and drawbacks of using the Health Level 7 standard, including the option for real time data exchange vs the flat file method. DESIGN: For data regarding vaccinations received by children aged 4 months through 6 years with Wisconsin addresses that were submitted to the Registry during 2010 and 2011, data timeliness (days from vaccine administration to date information was received) and completeness (percentage of records received that include core data elements for electronic storage) were compared by file submission method. RESULTS: Data submitted using Health Level 7 were substantially more timely than data submitted using the flat file method. Additionally, data submitted using Health Level 7 were substantially more complete for each of the core elements compared to flat file submission. CONCLUSIONS: Health care organizations that submit electronic data to immunization information systems should be aware that the technical decision to use the Health Level 7 format, particularly if real-time data exchange is employed, can result in more timely and accurate data. This will assist clinicians in adhering to the Advisory Committee on Immunization Practices schedule and reducing over-immunization.

Using a bayesian latent class model to evaluate the utility of investigating persons with negative polymerase chain reaction results for pertussis.

Pertussis remains difficult to control. Imperfect sensitivity of diagnostic tests and lack of specific guidance regarding interpretation of negative test results among patients with compatible symptoms may contribute to its spread. In this study, we examined whether additional pertussis cases could be identified if persons with negative pertussis test results were routinely investigated. We conducted interviews among 250 subjects aged ≤18 years with pertussis polymerase chain reaction (PCR) results reported from 2 reference laboratories in Wisconsin during July-September 2010 to determine whether their illnesses met the Centers for Disease Control and Prevention's clinical case definition (CCD) for pertussis. PCR validity measures were calculated using the CCD as the standard for pertussis disease. Two Bayesian latent class models were used to adjust the validity measures for pertussis detectable by 1) culture alone and 2) culture and/or more sensitive measures such as serology. Among 190 PCR-negative subjects, 54 (28%) had illnesses meeting the CCD. In adjusted analyses, PCR sensitivity and the negative predictive value were 1) 94% and 99% and 2) 43% and 87% in the 2 types of models, respectively. The models suggested that public health follow-up of reported pertussis patients with PCR-negative results leads to the detection of more true pertussis cases than follow-up of PCR-positive persons alone. The results also suggest a need for a more specific pertussis CCD.

Parental vaccine refusal in Wisconsin: a case-control study.

INTRODUCTION: Successful immunization programs have diminished parental fear of diseases and increased fear of vaccines. Children with nonmedical exemptions to school immunization requirements are at increased risk of acquiring and transmitting disease. We explored differences in vaccine attitudes, beliefs, and information sources among parents of exempt and vaccinated children. METHODS: Self-administered surveys were mailed to 780 parents of children with nonmedical exemptions (cases) and 1491 parents of fully-vaccinated children (controls). RESULTS: Vaccines most often refused by exempt children were varicella (49%) and hepatitis B (30%). The most common reason for claiming exemptions was vaccine might cause harm (57%). Parents of vaccinated children were less likely than parents of exempt children to report concern about vaccine safety, question the need for immunization, and oppose immunization requirements. Nearly 25% of parents of vaccinated children reported that children get more immunizations than are good for them and 34% expressed concern that children's immune systems could be weakened by too many immunizations. Both groups received information from health care professionals; parents of exempt children were more likely to also consult other sources. CONCLUSIONS: Our findings support the need for improved methods to communicate vaccine safety information. Further studies to explore vaccine safety concerns among parents are needed.

An immunization information system to meet evolving needs during the 2009-2010 Influenza A (H1N1) vaccination campaign.

In 2009, a monovalent H1N1 influenza (H1N1) vaccine was manufactured in response to the pandemic of 2009 influenza A (H1N1) virus infection that emerged earlier in the year. The overall allocation of the H1N1 vaccine to the states was the purview of the federal government; thereafter, the states were accountable for distributing and reporting the number of doses of H1N1 vaccine administered weekly. This report describes how the Wisconsin Immunization Registry (WIR) was updated and used during the H1N1 immunization campaign and its role in meeting the federal H1N1 immunization reporting requirements. Activities to enhance the registry's functionality included the creation of a rapid data entry screen for providers to facilitate the entry of data into the WIR, and enhancing the reporting capabilities of the WIR to generate H1N1-related reports at the local level. Results of these activities included an increase in the number of WIR users, higher reported numbers of seasonal influenza doses administered, and the establishment of data streams from new users. Data completeness, the ability to accurately forecast doses needed, and validating administered doses were challenges in the changing environment.