Table 2. VE stratification according to interval between date of vaccination and onset of ILI.

Period	Unadjusted VE %, (CI)	Adjusted VE %, (CI)
Overall	75.5% (95% CI 42.1–89.7)	76.0% (95% CI 42.1–89.7)
Period 1
(Difference between date of Vaccination and Illness Onset Date is greater than 7 d)	75 (40.8–89.5)	75.1 (40.9–89.5)
Period 2
(Difference between date of Vaccination and Illness Onset Date is greater than 14 d)	76.7 (40.4–90.9)	76.5 (39.8–90.8)
Period 3
(Difference between date of Vaccination and Illness Onset Date is greater than 21 days)	78.9 (40–92.5)	78.6 (39.2–92.5)