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 4
Association between influenza vaccination and incidence of multiple sclerosis and demyelinating conditions not ultimately diagnosed as multiple sclerosis, Manitoba, Canada, 2009–2012*
Vaccination status |
Multiple sclerosis, HR (95% CI) | Other demyelinating conditions, HR (95% CI) | |||
---|---|---|---|---|---|
Model A |
Model B |
Model A |
Model B |
||
1 Year after index date | |||||
Unvaccinated | Ref | Ref | Ref | Ref | |
Vaccinated A(H1N1)pdm09/TIV | 0.9 (0.6–1.2) | 0.9 (0.6–1.3) | 0.6 (0.3–1.2) | 0.6 (0.3–1.2) | |
A(H1N1) pdm09 alone | 0.9 (0.6–1.3) | 0.9 (0.6–1.4) | 0.5 (0.3–1.1) | 0.5 (0.3–1.2) | |
Concurrent A(H1N1) pdm09/TIV | 0.6 (0.3–1.3) | 0.6 (0.3–1.4) | 2.0 (0.4–10.9) | 2.3 (0.4–15) | |
TIV alone | 1.1 (0.5–2.3) | 1.2 (0.5–2.9) | NA | NA | |
Adjuvanted A(H1N1)pdm09 alone | 0.9 (0.6–1.4) | 0.9 (0.6–1.5) | 0.5 (0.2–1.1) | 0.5 (0.2–1.1) | |
Concurrent adjuvanted A(H1N1)pdm09/TIV | 0.6 (0.3–1.3) | 0.6 (0.3–1.3) | 2.0 (0.4–10.9) | 2.3 (0.4–14.8) | |
Unadjuvanted A(H1N1)pdm09 alone | 0.8 (0.2–3.4) | 0.8 (0.2–3.5) | 1.0 (0.1–15.9) | 1.0 (0.1–15.9) | |
Unadjuvanted A(H1N1)pdm09/TIV |
1.0 (0.1–15.9) |
1.1 (0.1–18.0) |
NA |
NA |
|
Entire follow-up period | |||||
Unvaccinated | Ref | Ref | Ref | Ref | |
Vaccinated A(H1N1)pdm09/TIV | 1.0 (0.8–1.3) | 1.1 (0.8–1.5) | 0.7 (0.4–1.1) | 0.7 (0.4–1.2) | |
A(H1N1) pdm09 alone | 1.0 (0.8–1.4) | 1.1 (0.8–1.5) | 0.5 (0.3–1.0) | 0.6 (0.3–1.1) | |
Concurrent A(H1N1) pdm09/TIV | 1.1 (0.6–1.8) | 1.2 (0.7–2) | 1.7 (0.4–7) | 2.1 (0.4–10.2) | |
TIV alone | 0.9 (0.5–1.9) | 1.2 (0.6–2.5) | 1.0 (0.1–7.1) | 1.5 (0.1–16.1) | |
Adjuvanted A(H1N1)pdm09 alone | 1.0 (0.8–1.4) | 1.1 (0.8–1.5) | 0.5 (0.3–1.0) | 0.5 (0.3–1.1) | |
Concurrent adjuvanted A(H1N1)pdm09/TIV | 1.1 (0.6–1.8) | 1.2 (0.7–2.0) | 1.7 (0.4–7.0) | 2.1 (0.4–10.1) | |
Unadjuvanted A(H1N1)pdm09 alone | 0.8 (0.2–3.0) | 0.8 (0.2–3.1) | 1.0 (0.1–15.9) | 1.0 (0.1–15.9) | |
Unadjuvanted A(H1N1)pdm09/TIV | 1.0 (0.1–15.9) | 1.2 (0.1–19.8) | NA | NA |
*Model A estimates were adjusted for matching variables (propensity scores, age, sex, and area of residence). Model B estimates also were adjusted for receipt of the 2008–09 TIV. A(H1N1)pdm09, pandemic influenza A(H1N1) strain; HR, hazard ratio; NA, cannot be estimated; ref, referent; TIV, trivalent influenza vaccine; TIV.