Flu Vaccine Effectiveness (VE) Data for 2022-2023
CDC References (severe flu outcomes): NVSN (preliminary): February 2023 ACIP Presentation [4.5 MB, 25 pages]; VISION: Adams, et al., 2024; Tenforde, et al., 2023; IVY: Lewis, et al., 2023
External Reference (medically attended flu illness): Marshfield, WI (preliminary): McLean, et al., 2023
Inclusion Dates by Network
Network
Network
Dates
Dates
September 2022 – January 2023
September 2022 – January 2023
October 2022 – March 2023
October 2022 – March 2023
October 2022 – February 2023
October 2022 – February 2023
Flu Vaccine Effectiveness for Children
Network (Setting) | Influenza positive N vaccinated / Total (%) | Influenza negative N vaccinated / Total (%) | VE (95% CI)¶ |
---|---|---|---|
Any Influenza A | |||
NVSN (Outpatient & Inpatient)*** | 123/640 (19%) | 750/2256 (33%) | 49 (36–60) |
NVSN (Outpatient)*** | 104/507 (21%) | 461/1330 (35%) | 42 (25–56) |
VISION (Outpatient) | 2058/13547 (15%) | 8459/31240 (27) | 48 (44–52) |
NVSN (Inpatient)*** | 19/131 (15%) | 288/913 (32%) | 68 (46–81) |
VISION (Inpatient) | 46/263 (17) | 534/1599 (33) | 40 (6–61) |
Influenza A(H1N1)pdm09 | |||
NVSN (Outpatient & Inpatient)*** | 23/139 (17%) | 750/2256 (33%) | 56 (28–72) |
Influenza A(H3N2) | |||
NVSN (Outpatient & Inpatient)*** | 98/478 (21%) | 750/2256 (33%) | 45 (29–58) |
*VE was estimated using the test-negative design comparing vaccination odds among persons who tested positive for influenza to vaccination odds among persons who tested negative for any influenza and SARS-CoV-2. Calculated as (1 − adjusted OR ) × 100%; ORs were estimated using logistic regression.
†Subtype was not available for VISION.
¶All networks adjusted for geographic region, age, calendar time. VISION adjusted for sex and race/ethnicity. VE estimates with fewer than 50 cases or from models that did not converge are not presented and are represented with a “—”
††Outpatient is defined as emergency departments for NVSN. Outpatient is defined as urgent care and emergency departments for VISION.
***NVSN data are preliminary.
Flu Vaccine Effectiveness for Adults
Network (Setting) | Influenza positive N vaccinated / Total (%) | Influenza negative N vaccinated / Total (%) | Adjusted VE (95% CI)¶ |
---|---|---|---|
All adults (aged ≥18 years) | |||
Any Influenza A | |||
VISION (Outpatient) | 3492/14484 (24%) | 28760/70905 (41%) | 44 (40–47) |
IVY (Inpatient) | 235/714 (33%) | 1462/2993 (49%) | 37 (27–46) |
VISION (Inpatient) | 733/1874 (39%) | 9700/17877 (54%) | 35 (27–43) |
Influenza A(H1N1)pdm09 | |||
IVY (Inpatient) | 44/145 (30%) | 1462/2993 (49%) | 47 (23–64) |
Influenza A(H3N2) | |||
IVY (Inpatient) | 96/286 (34%) | 1462/2993 (49%) | 29 (6–46) |
Adults (aged 18–64 years) | |||
Any Influenza A | |||
VISION (Outpatient) | 1728/10917 (16%) | 12289/44506 (28%) | 45 (41–48) |
IVY (Inpatient) | 90/383 (23%) | 579/1415 (41%) | 47 (30–60) |
VISION (Inpatient) | 161/661 (24%) | 1756/5133 (34%) | 23 (4–39) |
Older adults (aged ≥65 years) | |||
Any Influenza A | |||
VISION (Outpatient) | 1764/3567 (49%) | 16471/26399 (62%) | 41 (36–46) |
IVY (Inpatient) | 145/331 (44%) | 883/1578 (56%) | 27 (10–43) |
VISION (Inpatient) | 572/1213 (47%) | 7944/12744 (62%) | 41 (33–48) |
Immunocompromised Adults | |||
Any Influenza A | |||
IVY (Inpatient)1 | 41/103 (40%) | 281/500 (56%) | 49 (19–68) |
VISION (Outpatient)2 | 65/185 (35%) | 1109/2381 (47%) | 38 (10–58) |
VISION (Inpatient)2 | 141/314 (45%) | 2562/4414 (58%) | 32 (11–48) |
*VE was estimated using the test-negative design comparing vaccination odds among persons who tested positive for influenza to vaccination odds among persons who tested negative for any influenza and SARS-CoV-2. Calculated as (1 − adjusted OR) × 100%; ORs were estimated using logistic regression.
†Subtype was not available for VISION.
¶All networks adjusted for geographic region, age, calendar time. IVY and VISION, adjusted for sex and race/ethnicity. VE estimates with fewer than 50 cases or from models that did not converge are not presented and are represented with a “—”
**Outpatient is defined as urgent care and emergency departments for VISION.
1 Includes active solid-organ cancer, active hematologic cancer, solid-organ transplant, bone marrow/stem cell transplant, HIV infection, congenital immunodeficiency syndrome, use of an immunosuppressive medication within the last 30 days, splenectomy, graft-versus-host disease (currently or in the past), or any other condition that causes moderate or severe immunosuppression.
2Defined as at least one discharge diagnosis for solid malignancy, hematologic malignancy, rheumatologic or inflammatory disorder, other intrinsic immune condition or immunodeficiency, or organ or stem cell transplant.
McLean HQ, Petrie JG, Hanson KE, et al. Interim Estimates of 2022–23 Seasonal Influenza Vaccine Effectiveness — Wisconsin, October 2022–February 2023. MMWR Morb Mortal Wkly Rep 2023;72:201–205. DOI: http://dx.doi.org/10.15585/mmwr.mm7208a1.