CDC’s Vaccine Effectiveness Networks
In the United States, CDC and the Advisory Committee on Immunization Practices (ACIP) recommends influenza vaccines for all persons older than 6 months of age. Monitoring the performance of influenza vaccines is important for understanding and improving the benefits of vaccine. CDC uses three networks to estimate vaccine effectiveness: the Flu VE Network, the Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN), and the National Vaccine Surveillance Network (NVSN).
Started in 2003-04 and collects vaccine effectiveness data on outpatient illness with laboratory-confirmed flu.
Started in 2015-16 and collects vaccine effectiveness data on hospitalizations with laboratory-confirmed flu in adults 18 years of age and older.
See Seasonal Influenza Vaccine Effectiveness, 2004-2019 for season-by-season data and references.