Table 2.
Characteristics of Participants by Influenza Vaccination Status, 4 October 2021–30 April 2022a
| Characteristic | Vaccinateda (n = 2463) | Unvaccinated (n = 1849) | P Valueb |
|---|---|---|---|
| Study site | <.01 | ||
| ȃCalifornia | 333 (13.5) | 158 (8.5) | |
| ȃMichigan | 257 (10.4) | 67 (3.6) | |
| ȃPennsylvania | 278 (11.3) | 228 (12.3) | |
| ȃTennessee | 371 (15.1) | 279 (15.1) | |
| ȃTexas | 351 (14.3) | 590 (31.9) | |
| ȃWashington | 290 (11.8) | 128 (6.9) | |
| ȃWisconsin | 583 (23.7) | 399 (21.6) | |
| Sex | <.01 | ||
| ȃMale | 919 (37.3) | 768 (41.5) | |
| ȃFemale | 1542 (62.6) | 1079 (58.4) | |
| Age, y, median (IQR) | 36.0 (15.0–56.0) | 25.0 (12.0–41.0) | <.01 |
| Age group | <.01 | ||
| ȃ6 mo–8 y | 394 (16.0) | 330 (17.8) | |
| ȃ9–17 y | 255 (10.4) | 365 (19.7) | |
| ȃ18–49 y | 1010 (41.0) | 853 (46.1) | |
| ȃ50–44 y | 454 (18.4) | 215 (11.6) | |
| ȃ≥65 y | 350 (14.2) | 86 (4.7) | |
| Race/ethnicity | <.01 | ||
| White, non-Hispanic | 1483 (60.2) | 961 (52.0) | |
| Black, non-Hispanic | 93 (3.8) | 136 (7.4) | |
| Hispanic, any race | 278 (11.3) | 332 (18.0) | |
| Other, non-Hispanic | 243 (9.9) | 146 (7.9) | |
| Unknown | 366 (14.9) | 274 (14.8) | |
| Illness onset to enrollment, d | .44 | ||
| <3 | 1112 (45.1) | 807 (43.6) | |
| 3–4 | 810 (32.9) | 642 (34.7) | |
| 5–7 | 541 (22.0) | 400 (21.6) | |
| General self-reported health status | .06 | ||
| Excellent | 655 (26.6) | 530 (28.7) | |
| Very good | 942 (38.2) | 676 (36.6) | |
| Good | 637 (25.9) | 487 (26.3) | |
| Fair/poor | 221 (9.0) | 153 (8.3) | |
| ≥1 high-risk medical condition present | <.01 | ||
| ȃNo | 1764 (71.6) | 1502 (81.2) | |
| Yesc | 653 (26.5) | 322 (17.4) | |
| COVID-19 vaccination status | |||
| ȃ0 doses | 211 (8.6) | 666 (36.0) | <.01 |
| 1–2 doses | 652 (26.5) | 679 (36.7) | <.01 |
| ≥3 doses | 1299 (52.7) | 268 (14.5) | <.01 |
| Influenza rRT-PCR result | |||
| ȃNegative | 2265 (92.0) | 1579 (85.4) | <.01 |
| ȃInfluenza A | 198 (8.0) | 270 (14.6) | |
| ȃA(H1N1)pdm09 | 0 (0) | 2 (0.1) | |
| ȃA(H3N2) | 182 (7.4) | 258 (14.0) | |
| ȃInfluenza B | 0 (0) | 0 (0) |
Data are presented as No. (%) unless otherwise indicated.
Abbreviations: COVID-19, coronavirus disease 2019; IQR, interquartile range; rRT-PCR, real-time reverse-transcription polymerase chain reaction.
Participants who tested positive for severe acute respiratory syndrome coronavirus 2 are excluded.
P value from χ2 test comparing proportions by test result.
Self-reported presence of at least 1 high-risk medical condition including heart disease, lung disease, diabetes, cancer, liver or kidney disease, or immunosuppression.