Exposure | Period | No. of person-days at risk | No. of events | Incidence rate (per 100 person-days) | IRRa (95 % CI) |
---|---|---|---|---|---|
Background periodd | 976,010 | 739 | 0.08 | 1 | |
2 weeks before vaccination day | 40,320 | 23 | 0.06 | 0.76 (0.50–1.43) | |
Vaccinationb | Day of vaccination | 2880 | 3 | 0.10 | 1.39 (0.46–4.35) |
1–3 days after vaccination | 8640 | 13 | 0.15 | 2.00 (1.15–3.51) | |
4–7 days after vaccination | 11,520 | 7 | 0.06 | 0.81 (0.38 – 1.73) | |
Background period | 95,724 | 63 | 0.07 | 1 | |
2 weeks before influenza diagnosis | 3962 | 9 | 0.23 | 3.96 (1.81–8.65) | |
Influenzac | Day of influenza diagnosis | 283 | 19 | 6.71 | 116.70 (62.81–216.90) |
1–3 days after influenza diagnosis | 849 | 5 | 0.59 | 10.12 (3.82–26.82) | |
4–7 days after influenza diagnosis | 1132 | 1 | 0.09 | 1.50 (0.20–11.17) |