At a glance
Inclusion Dates by Network
Network
Dates
September 2022 – January 2023
October 2022 – March 2023
October 2022 – February 2023
Children: Flu Vaccine Effectiveness
Number and percentage of children (6 months to 17 years) receiving seasonal influenza vaccine and vaccine effectivenessA by influenza type and subtypeB— two networks, United States, 2022–23 influenza season
| 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) |
* 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 “—”
**NVSN data are preliminary.
Adults: Flu Vaccine Effectiveness
Number and percentage of adults (≥18 years) receiving seasonal influenza vaccine and vaccine effectivenessA by influenza type and subtypeB— two networks, United States, 2022–23 influenza season
| 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)** | 41/103 (40%) | 281/500 (56%) | 49 (19–68) |
| VISION (Outpatient)*** | 65/185 (35%) | 1109/2381 (47%) | 38 (10–58) |
| VISION (Inpatient)*** | 141/314 (45%) | 2562/4414 (58%) | 32 (11–48) |
*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 "—"
** 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.
***Defined 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.
- 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.
- CDC References (severe flu outcomes): NVSN (preliminary): February 2023 ACIP Presentation
- VISION: Adams, et al., 2024; Tenforde, et al., 2023
- IVY: Lewis, et al., 2023
- U.S. Flu VE Network: Chung, et al., 2024
- 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.
- 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 “—”
- NVSN data are preliminary.