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 2023-2024 flu seasons.
Past Seasons
Estimated Number of Flu Illnesses, Medical Visits, Hospitalizations, and Deaths Prevented by Vaccination, by Age Group, 2010-2011 through 2023-2024 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 | (1,300,000, 4,800,000) | 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 | (570,000, 1,700,000) | 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 | (0, 1,200,000) | 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 | (630,000, 2,000,000) | 100,000 | (35,000, 250,000) | 12,000 | (2,300, 41,000) |
| 2014-2015 | 1,400,000 | (0, 4,200,000) | 700,000 | (0, 1,000,000) | 39,000 | (160, 190,000) | 3,700 | (10, 20,000) |
| 2015-2016 | 5,300,000 | (2,500,000, 9,200,000) | 2,700,000 | (1,300,000, 3,900,000) | 70,000 | (15,000, 170,000) | 6.400 | (510, 20,000) |
| 2016-2017 | 5,300,000 | (2,400,000, 11,000,000) | 2,700,000 | (2,300,000, 7,200,000) | 72,000 | (13,000, 190,000) | 5,200 | (360, 16,000) |
| 2017-2018 | 6,000,000 | (4,700,000, 7,500,000) | 3,100,000 | (16,000,000, 25,000,000) | 82,000 | (45,000, 160,000) | 4,900 | (1,500, 14,000) |
| 2018-2019 | 2.800,000 | (1,800,000, 4,400,000) | 1,500,000 | (12,000,000, 19,000,000) | 36,000 | (13,000, 96,000) | 2,500 | (240, 13,000) |
| 2019-2020 | 6,700,000 | (5,100,000, 8,400,000) | 3,300,000 | (13,000,000, 29,000,000) | 98,000 | (50,000, 150,000) | 6,300 | (2,100, 15,000) |
| 2021-2022 | 1,900,000 | (1,100,000, 3,000,000) | 990,000 | (4,000,000, 8,600,000) | 26,000 | (6,700, 72,000) | 1,500 | (10, 7,500) |
| 2022-2023** | 5,500,000 | (4,600,000, 8,400,000) | 2,700,000 | (12,000,000, 21,000,000) | 71,000 | (56,000, 130,000) | 4,300 | (2,300, 13,000) |
| 2023-2024** | 9,800,000 | (8,100,000, 17,000,000) | 4,800,000 | (15,000,000, 27,000,000) | 120,000 | (95,000, 220,000) | 7,900 | (4,000, 44,000) |
* 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]