Volume 18, Number 5—May 2012
Research
No Association between 2008–09 Influenza Vaccine and Influenza A(H1N1)pdm09 Virus Infection, Manitoba, Canada, 2009
Salaheddin M. Mahmud
, Paul Van Caeseele, Gregory Hammond, Carol Kurbis, Tim Hilderman, and Lawrence Elliott
, Paul Van Caeseele, Gregory Hammond, Carol Kurbis, Tim Hilderman, and Lawrence ElliottTable 4
Effect of receipt of 2008–09 TIV on risk for infection with influenza A(H1N1)pdm09 virus, Manitoba, Canada, 2009*
| Data subsets, by demographic and clinical characteristic | No. community controls, n = 2,479 | No. community case-patients, n = 626 | Odds ratio (95% CI) |
|
|---|---|---|---|---|
| Model A† | Model C‡ | |||
| Sex | ||||
| F | 1,468 | 322 | 0.8 (0.6–1.1) | 1.0 (0.7–1.5) |
| M | 1,011 | 304 | 0.6 (0.4–0.9) | 1.1 (0.7–1.8) |
| p for interaction | 0.304 | 0.997 | ||
| Age group, y | ||||
| 0.5–49 | 1,776 | 549 | 0.9 (0.7–1.2) | 0.9 (0.6–1.3) |
| >50 | 703 | 77 | 1.0 (0.7–1.7) | 1.2 (0.6–2.4) |
| p for interaction | 0.563 | 0.308 | ||
| Age, y | ||||
| 0.5–4 | 210 | 62 | 1.1 (0.5–2.4) | 1.3 (0.3–4.9) |
| 5–19 | 413 | 223 | 1.1 (0.6–1.8) | 1.6 (0.7–3.6) |
| 20–34 | 553 | 154 | 0.9 (0.5–1.5) | 0.9 (0.5–1.8) |
| 35–49 | 600 | 110 | 1.0 (0.6–1.7) | 0.9 (0.4–1.7) |
| 50–59 | 331 | 56 | 1.4 (0.8–2.6) | 1.7 (0.7–4.5) |
| >60 | 372 | 21 | 1.4 (0.6–3.5) | 0.4 (0.1–3.4) |
| p for interaction | 0.882 | 0.916 | ||
| Locality of residence | ||||
| Rural | 1,073 | 285 | 0.8 (0.5–1.1) | 1.0 (0.6–1.7) |
| Urban | 1,406 | 341 | 0.7 (0.5–0.9) | 1.0 (0.7–1.5) |
| p for interaction | 0.632 | 0.628 | ||
| Area of residence | ||||
| North | 362 | 156 | 1.0 (0.6–1.7) | 1.3 (0.6–2.8) |
| South | 2,117 | 470 | 0.7 (0.5–0.9) | 0.9 (0.7–1.3) |
| p for interaction | 0.236 | 0.255 | ||
| Epidemic phase, 2009 | ||||
| Apr 27–Jun 20 | 1,071 | 423 | 0.7 (0.5–0.9) | 0.9 (0.6–1.4) |
| Jun 21–Aug 21 | 1,408 | 203 | 0.8 (0.5–1.1) | 1.1 (0.6–1.7) |
| p for interaction | 0.586 | 0.482 | ||
| Chronic disease | ||||
| No | 1,931 | 536 | 0.8 (0.6–1.0) | 0.9 (0.6–1.3) |
| Yes | 548 | 90 | 1.0 (0.6–1.4) | 1.3 (0.7–2.3) |
| p for interaction | 0.402 | 0.330 | ||
| Respiratory disease | ||||
| No | 1,456 | 386 | 0.7 (0.5–1.0) | 0.9 (0.6–1.3) |
| Yes | 1,023 | 240 | 0.7 (0.5–1.0) | 1.3 (0.8–2.0) |
| p for interaction | 0.831 | 0.764 | ||
*TIV, inactivated trivalent influenza vaccine.
†Unadjusted model.
‡Model adjusted for age, sex, region of residence, Socioeconomic Factor Index (24), and week of specimen collection, no. hospital admissions and family physician visits in previous 12 mo, pregnancy, presence of a chronic or immunocompromising medical condition, and antiviral drug use. Model also included mutual adjustment for 2007–09 TIV and PPV23.
