Influenza VE for Prevention of Influenza A and B–Associated Hospitalizations Among Children by Using Documented Influenza Vaccination Status Supplemented by Parental Report, NVSN, 2018–2019
| Influenza-Positive (Case Patients) | Influenza-Negative (Control Patients) | VE | ||||
|---|---|---|---|---|---|---|
| No. Vaccinated/Total | % | No. Vaccinated/Total | % | VE, % (95% CI) | Adjusteda VE, % (95% CI) | |
| All influenza viruses | ||||||
| All ages | 106/226 | 47 | 964/1566 | 62 | 45 (27 to 58) | 41 (20 to 56) |
| 6 mo to <5 y | 54/109 | 50 | 730/1146 | 64 | 44 (17 to 62) | 46 (19 to 64) |
| 5–17 y | 52/117 | 44 | 234/420 | 56 | 36 (4 to 58) | 23 (−23 to 51) |
| A(H3N2) viruses | 50/108 | 46 | 964/1566 | 62 | 46 (20 to 63) | 41 (11 to 61) |
| A(H1N1)pdm09 viruses | 36/83 | 43 | 964/1566 | 62 | 52 (25 to 69) | 47 (16 to 67) |
↵a Adjusted for study site, age as a continuous variable, and calendar time (monthly intervals).