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 5
Association between receipt of seasonal influenza vaccine and subsequent risk for hospitalization among patients with influenza A(H1N1)pdm09 virus infection, Manitoba, Canada, 2009*
| Variable | No. community case-patients, n = 626 | No. hospitalized case-patients, n = 205 | Odds ratio (95% CI) |
||
|---|---|---|---|---|---|
| Model A† | Model B‡ | Model C§ | |||
| Received TIV | |||||
| 2007–08 | 123 | 37 | 0.9 (0.6–1.4) | 0.6 (0.3–1.0) | 0.4 (0.2–0.8) |
| 2008–09 | 109 | 39 | 1.1 (0.7–1.7) | 0.8 (0.5–1.3) | 0.6 (0.3–1.3) |
| Vaccinated with | |||||
| None | 466 | 149 | Reference | Reference | Reference |
| 2007–08 only | 51 | 17 | 1.0 (0.6–1.9) | 0.7 (0.3–1.4) | 0.5 (0.2–1.2) |
| 2008–09 only | 37 | 19 | 1.6 (0.9–2.9) | 1.3 (0.6–2.6) | 0.8 (0.4–1.8) |
| Both | 72 | 20 | 0.9 (0.5–1.5) | 0.5 (0.3–1.0) | 0.2 (0.1–0.5) |
| No. TIVs in past 5 y | |||||
| None | 383 | 119 | Reference | Reference | Reference |
| >1 | 243 | 86 | 1.1 (0.8–1.6) | 0.9 (0.6–1.4) | 0.8 (0.5–1.2) |
| 1–3 | 187 | 65 | 1.1 (0.8–1.6) | 1.0 (0.6–1.4) | 0.8 (0.5–1.3) |
| 4–5 | 56 | 21 | 1.2 (0.7–2.1) | 0.8 (0.4–1.6) | 0.5 (0.2–1.3) |
| 5 | 19 | 9 | 1.5 (0.7–3.4) | 1.1 (0.4–3.2) | 0.6 (0.2–2.3) |
| Ever received PPV23 | 41 | 32 | 2.6 (1.6–4.3) | 1.8 (1.0–3.6) | 1.7 (0.8–3.8) |
| Vaccinated with | |||||
| None | 499 | 153 | Reference | Reference | Reference |
| 2008–09 TIV only | 86 | 20 | 0.8 (0.5–1.3) | 0.6 (0.3–1.1) | 0.5 (0.2–1.1) |
| PPV23 only | 18 | 13 | 2.4 (1.1–4.9) | 1.4 (0.6–3.4) | 1.2 (0.4–3.1) |
| Both | 23 | 19 | 2.7 (1.4–5.1) | 1.9 (0.8–4.6) | 1.6 (0.5–4.7) |
*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. 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.
