Purpose
This web page provides estimates on the burden of seasonal influenza (flu) and of the impact of annual flu vaccination in the United States for the 2010-2011 through the 2022-2023 flu seasons.
Past Seasons
Estimated Number of Flu Illnesses, Medical Visits, Hospitalizations, and Deaths Prevented by Vaccination, by Age Group, 2010-2011 through 2022-2023 Flu Seasons
| Prevented Symptomatic Illnesses | Prevented Medical Visits | Prevented Hospitalizations | Prevented Deaths | |||||
|---|---|---|---|---|---|---|---|---|
| Season | Estimate | 95% UI | Estimate | 95% UI | Estimate | 95% UI | Estimate | 95% UI |
| 2010-2011 | 5,600,000 | (3,100,000, 14,000,000) | 2,800,000 | (1,700,000, 6,900,000) | 80,000 | (19,000, 380,000) | 9,800 | (1,300, 58,000) |
| 2011-2012 | 2,200,000 | (830,000, 12,000,000) | 1,100,000 | (410,000, 5,400,000) | 44,000 | (4,900, 320,000) | 4,200 | (320, 41,000) |
| 2012-2013 | 5,500,000 | (3,700,000, 11,000,000) | 2,700,000 | (1,900,000, 5,300,000) | 60,000 | (23,000, 290,000) | 3,700 | (850, 25,000) |
| 2013-2014 | 7,500,000 | (4,300,000, 12,000,000) | 3,500,000 | (2,000,000, 5,500,000) | 100,000 | (35,000, 250,000) | 12,000 | (2,300, 41,000) |
| 2014-2015 | 1,400,000 | (8,300, 4,200,000) | 700,000 | (4,200, 2,100,000) | 39,000 | (160, 190,000) | 3,700 | (13, 20,000) |
| 2015-2016 | 5,300,000 | (2,500,000, 9,200,000) | 2,700,000 | (1,300,000, 4,500,000) | 70,000 | (15,000, 170,000) | 5,900 | (510, 20,000) |
| 2016-2017 | 5,300,000 | (2,400,000, 11,000,000) | 2,700,000 | (1,300,000, 5,400,000) | 72,000 | (13,000, 190,000) | 5,200 | (360, 16,000) |
| 2017-2018 | 5,900,000 | (4,700,000, 7,400,000) | 3,100,000 | (2,400,000, 3,900,000) | 82,000 | (40,000, 100,000) | 4,800 | (1,000, 14,000) |
| 2018-2019 | 3,100,000 | (2,400,000, 4,700,000) | 1,600,000 | (1,200,000, 2,400,000)) | 43,000 | (30,000, 160,000) | 2,800 | (700, 16,000)) |
| 2019-2020 | 7,000,000 | (5,400,000, 8,900,000) | 3,400,000 | (2,600,000, 4,300,000) | 100,000 | (52,000, 153,000) | 7,200 | (2,000, 27,000) |
| 2021-2022** | 1,800,000 | (1,000,000, 2,700,000) | 900,000 | (500,000, 1,400,000) | 22,000 | (6,000, 62,000) | 1,100 | (0, 7,000) |
| 2022-2023** | 5,900,000 | (4,000,000, 7,700,000) | 2,900,000 | (1,900,000, 3,800,000) | 64,000 | (34,000, 96,000) | 3,600 | (0, 12,000) |
* Estimates are not available for the 2020-2021 flu season due to minimal influenza activity.
** Estimates are preliminary and will be updated when additional information for that season is available.
- Deaths prevented by influenza vaccination in the U.S. during the seasons 2005/06 through 2013/14. Vaccine. 2015
- Case-control study of vaccine effectiveness in preventing laboratory-confirmed influenza hospitalizations in older adults, United States, 2010-2011. Clin Infect Dis.
- Influenza Illness and Hospitalizations Prevented by Influenza Vaccination in the United States, 2005-2011. PLoS One.
- Modeling the Effect of Different Vaccine Effectiveness Estimates on the Number of Vaccine-Prevented Influenza-Associated Hospitalizations in Older Adults [136 KB, 4 pages]