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 3
Association between receipt of seasonal influenza vaccine and subsequent infection with influenza A(H1N1)pdm09 virus, by vaccine type, Manitoba, Canada, 2009*
| Variable | No. community controls, n = 2,479 | No. community case-patients, n = 626 | Odds ratio (95% CI) |
||
|---|---|---|---|---|---|
| Model A† | Model B‡ | Model C§ | |||
| Received TIV | |||||
| 2007–08 | 544 | 123 | 0.9 (0.7–1.1) | 1.3 (1.0–1.7) | 1.4 (1.0–1.9) |
| 2008–09 | 564 | 109 | 0.7 (0.6–0.9) | 1.1 (0.8–1.4) | 1.0 (0.7–1.4) |
| Vaccinated with | |||||
| None | 1,728 | 466 | Referent | Referent | Referent |
| 2007–08 only | 187 | 51 | 1.0 (0.7–1.4) | 1.3 (0.9–1.8) | 1.3 (0.9–1.9) |
| 2008–09 only | 207 | 37 | 0.7 (0.5–1.0) | 0.9 (0.6–1.3) | 0.9 (0.6–1.4) |
| Both | 357 | 72 | 0.7 (0.6–1.0) | 1.3 (0.9–1.8) | 1.4 (1.0–2.0) |
| No. TIVs in past 5 y | |||||
| None | 1,450 | 383 | Referent | Referent | Referent |
| At least 1 | 1,029 | 243 | 0.9 (0.7–1.1) | 1.2 (1.0–1.5) | 1.2 (1.0–1.5) |
| 1–3 | 711 | 187 | 1.0 (0.8–1.2) | 1.2 (0.9–1.5) | 1.2 (0.9–1.5) |
| 4–5 | 318 | 56 | 0.7 (0.5–0.9) | 1.3 (0.9–1.9) | 1.4 (1.0–2.2) |
| 5 | 156 | 19 | 0.5 (0.3–0.8) | 0.8 (0.4–1.4) | 0.8 (0.4–1.4) |
| Ever received PPV23 | 343 | 41 | 0.4 (0.3–0.6) | 0.9 (0.6–1.4) | 0.9 (0.6–1.5) |
| Vaccinated with | |||||
| None | 1,796 | 499 | Referent | Referent | Referent |
| 2008–09 TIV only | 340 | 86 | 0.9 (0.7–1.2) | 1.1 (0.8–1.4) | 1.0 (0.7–1.4) |
| PPV23 only | 119 | 18 | 0.5 (0.3–0.9) | 0.9 (0.5–1.5) | 0.9 (0.5–1.6) |
| Both | 224 | 23 | 0.4 (0.2–0.6) | 1.0 (0.6–1.7) | 1.0 (0.5–1.8) |
*TIV, inactivated trivalent influenza vaccine; PPV23, pneumococcal polysaccharide vaccine.
†Unadjusted model.
‡Model adjusted for age, sex, region of residence, Socioeconomic Factor Index (24), and week of specimen collection.
§Model adjusted for all model B variables plus no. of hospital admissions and family physician visits in previous 12 mo, pregnancy, having a chronic or immunocompromising medical condition, and antiviral drug use. Model also included mutual adjustment for 2007–09 TIV and PPV23.
