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Influenza Vaccination Effectiveness in the US

Clin Infect Dis; ePub 2019 Feb 2; Rolfes, et al

During the 2017‒2018 influenza season in the US, influenza vaccination reduced the risk of medically-attended influenza by 38%, a recent study found. Researchers used national age-specific estimates of 2017‒2018 influenza vaccine coverage and disease burden to estimated vaccine effectiveness (VE). They found:

  • The VE against outpatient medically-attended, laboratory-confirmed influenza was 38%.
  • Influenza vaccination was estimated as preventing 7.1 million illnesses, 3.7 million medical visits, 109,000 hospitalizations, and 8,000 deaths.
  • Vaccination prevented 10% of expected hospitalizations overall and 41% among children aged 6 months to 4 years.


Rolfes MA, Flannery B, Chung J, et al. Effects of influenza vaccination in the United States during the 2017–2018 influenza season. [Published online ahead of print February 2, 2019]. Clin Infect Dis. doi:10.1093/cid/ciz075.