Using existing surveillance data, a method was developed for assessing the impact of influenza vaccination where impact is defined as either the number of averted outcomes or as the prevented disease fraction (the number of cases estimated to have been averted relative to the number of cases that would have occurred in the absence of vaccination).
During the 6-year study period, the number of influenza illnesses averted by vaccination ranged from a low of approximately 1.1 million (95 percent confidence interval (CI) 0.6–1.7 million) during the 2006–2007 season to a high of 5 million (CI 2.9–8.6 million) during the 2010–2011 season while the number of averted hospitalizations ranged from a low of 7,700 (CI 3,700–14,100) in 2009–2010 to a high of 40,400 (CI 20,800–73,000) in 2010–2011. Prevented fractions varied across age groups and over time. The highest prevented fraction in the study period was observed in 2010–2011, reflecting the post-pandemic expansion of vaccination coverage. Influenza vaccination programs in the US produce a substantial health benefit in terms of averted cases, clinic visits and hospitalizations. The results underscore the potential for additional disease prevention through increased vaccination coverage, particularly among nonelderly adults, and increased vaccine effectiveness, particularly among the elderly.
Report Title: Influenza Illness and Hospitalizations Averted By Influenza Vaccination in the United States, 2005–2011. (2013 PLOSOne) http://www.plosone.org/article/info percent3Adoi percent2F10.1371 percent2Fjournal.pone.0066312
Agency Sponsor: CDC, Centers for Disease Control and Prevention
Federal Contact: Thomas Chapel, 404-639-2116
Performer: CDC Intramural
Record ID: 10206 (June 19, 2013)