Past Seasons Vaccine Effectiveness Estimates
These pages includes information about the estimated seasonal influenza vaccine effectiveness from past seasons, including tables of the estimated vaccine effectiveness (and 95% credible interval [Cr I]) by age group and virus subtype. Information on how these estimates are calculated can be found on CDC’s web page How CDC Estimates vaccine efficacy and effectiveness.
Table. Adjusted vaccine effectiveness estimates for influenza seasons from 2004-2018
CDC calculates vaccine effectiveness estimates through the U.S. VE Network
|
Influenza Season† |
Reference |
Study Site(s) |
No. of Patients‡ |
Adjusted Overall VE (%) |
95% CI |
|---|---|---|---|---|---|
| Flannery 2020external icon | WI, MI, PA, TX, WA | 3,254 |
29 |
21, 35 | |
| Rolfes 2019external icon | WI, MI, PA, TX, WA | 8,436 |
38 |
31, 43 | |
| Flannery 2019external icon | WI, MI, PA, TX, WA | 7410 |
40 |
32, 46 | |
|
WI, MI, PA, TX, WA |
6879 |
48 |
41, 55 |
||
|
WI, MI, PA, TX, WA |
9311 |
19 |
10, 27 |
||
|
WI, MI, PA, TX, WA |
5999 |
52 |
44, 59 |
||
|
WI, MI, PA, TX, WA |
6452 |
49 |
43, 55 |
||
|
WI, MI, PA, TX, WA |
4771 |
47 |
36, 56 |
||
|
2010-11 |
WI, MI, NY, TN |
4757 |
60 |
53, 66 |
|
|
2009-10 |
WI, MI, NY, TN |
6757 |
56 |
23, 75 |
|
|
2008-09 |
Unpublished |
WI, MI, NY, TN |
6713 |
41 |
30, 50 |
|
2007-08 |
WI |
1914 |
37 |
22, 49 |
|
|
2006-07 |
WI |
871 |
52 |
22, 70 |
|
|
2005-06 |
WI |
346 |
21 |
-52, 59 |
|
|
2004-05 |
WI |
762 |
10 |
-36, 40 |
* Vaccine effectiveness estimates for 2018-2019 are preliminary estimates and will be updated with final estimates at the end of the 2018-2019 U.S. influenza season.
* From 2004-05 through 2010-11, the Network also enrolled inpatients.
† Vaccine effectiveness (VE) estimates for the 2008-2009 flu season have not yet been published.
‡ Number of patients used in VE calculation.