Analyzing Trends In Influenza-Like Illness and Influenza Vaccine Uptake to Develop Targeted Vaccination Messages

Background: MDCH participates in the Outpatient Influenza-like Illness Surveillance Network (ILINet), a collaborative effort between CDC, health departments, and sentinel providers, to monitor the impact of influenza.  Throughout Michigan, 92 ILINet providers submit weekly reports on the number of patients seen and the number of visits for ILI by age group. The Michigan Care Improvement Registry (MCIR) collects reliable immunization information from providers who are required to report immunizations given to persons born on or after January 1, 1994.   Each flu season has it own unique characteristics and challenges which have included: decreased vaccine supply, increased burden of disease, vaccine and circulating strain mismatch and distribution challenges.  National and MCIR data show that most seasonal flu doses are given in the first 2-3 months of the season despite recommendations to vaccinate throughout the season and expansions in recommendations for annual immunization. 

Objectives: Participants will learn how understanding trends in influenza vaccine uptake and burden of disease can be used to develop targeted messages to the public and private providers. 

Methods: Using MCIR and ILINet data, the unique characteristics of the five previous flu seasons will be presented. Each ILINet provider site is categorized by practice type; for this study, ILI data from “Family Practice” and “Pediatric” sites will be used. Trends in flu vaccine uptake and the burden of disease will be described.  

Results: These data are used to create targeted messages to providers and the public including messages on the importance of vaccinating throughout the entire flu season. 

Conclusions: Many strengths and weaknesses of influenza vaccination strategies have been identified through analyses of previous influenza seasons.  With expanded recommendations and increased vaccine supply, changing the way we vaccinate against influenza by expanding the timeframe in which vaccine is administered is more important now than ever before.