Volume 24, Number 7—July 2018
Research
Registry Cohort Study to Determine Risk for Multiple Sclerosis after Vaccination for Pandemic Influenza A(H1N1) with Arepanrix, Manitoba, Canada
Table 3
Crude and age-standardized rates of incident demyelinating conditions not ultimately diagnosed as multiple sclerosis and influenza vaccination status, Manitoba, Canada, 2009–2012*
Vaccination status |
No. events |
Rate (95% CI) | Rate ratio (95% CI) | |||
---|---|---|---|---|---|---|
Crude |
Age-standardized |
Crude |
Age-adjusted |
|||
1 year after index date | ||||||
Unvaccinated | 27 | 5.9 (4.1–8.6) | 6.9 (2.6–11.1) | 1 | 1 | |
Vaccinated A(H1N1)pdm09/TIV | 17 | 4.7 (2.9–7.6) | 4.7 (0.0–10.6) | 0.8 (0.4–1.5) | 0.7 (0.1–6.4) | |
A(H1N1) pdm09 alone | s | s | 5.6 (0.0–13.3) | 0.8 (0.4–1.6) | 0.8 (0.1–10.6) | |
Concurrent A(H1N1) pdm09/TIV | s | s | 7.8 (0.0–17.0) | 1.4 (0.6–3.7) | 1.1 (0.1–15.2) | |
TIV alone | 0 | 0 | NA | NA | NA | |
Adjuvanted A(H1N1)pdm09 alone | 11 | 4.7 (2.6–8.5) | 5.4 (0.0–13.1) | 0.8 (0.4–1.6) | 0.8 (0.1–10.8) | |
Concurrent adjuvanted A(H1N1)pdm09/TIV | s | s | 8.0 (0.0–17.3) | 1.5 (0.6–3.8) | 1.2 (0.1–15.5) | |
Unadjuvanted A(H1N1)pdm09 alone | s | s | 6.2 (0.0–16.0) | 1.7 (0.2–12.8) | 0.9 (0.0–18.1) | |
Unadjuvanted A(H1N1)pdm09/TIV |
0 |
0 |
NA |
NA |
NA |
|
Entire follow-up period | ||||||
Unvaccinated | 40 | 3.3 (2.4–4.5) | 3.6 (0.8–6.3) | 1 | 1 | |
Vaccinated A(H1N1)pdm09/TIV | 25 | 2.9 (1.9–4.2) | 2.9 (0.0–7.1) | 0.9 (0.5–1.4) | 0.8 (0.1–6.2) | |
A(H1N1)pdm09 alone | 17 | 3.0 (1.9–4.9) | 3.5 (0.0–9.1) | 0.9 (0.5–1.6) | 1.0 (0.1–10.3) | |
Concurrent A(H1N1)pdm09/TIV | s | s | 3.8 (0.0–10.7) | 1.1 (0.5–2.6) | 1.1 (0.1–15.6) | |
TIV alone | s | s | 0.4 (0.0–2.1) | 0.4 (0.1–1.7) | 0.1 (0.0–1.0) | |
Adjuvanted A(H1N1)pdm09 alone | 15 | 2.8 (1.7–4.6) | 3.2 (0.0–8.9) | 0.8 (0.5–1.5) | 0.9 (0.1–10.5) | |
Concurrent adjuvanted A(H1N1)pdm09/TIV | 6 | 3.8 (1.7–8.4) | 4.0 (0.0–10.9) | 1.1 (0.5–2.7) | 1.1 (0.1–16.1) | |
Unadjuvanted A(H1N1) alone | s | s | 7.4 (0.0–18.0) | 2.5 (0.6–10.5) | 2.1 (0.1–39.9) | |
Unadjuvanted A(H1N1)pdm09/TIV | 0 | 0 | NA | NA | NA |
*Rates are per 100,000 person-years. A(H1N1)pdm09, pandemic influenza A(H1N1) strain; NA, cannot be estimated; s, suppressed because of small sample size (n = 1–5) in accordance with the requirements of the data custodian; TIV, trivalent influenza vaccine.