Table 3.
Pooled adjusted seasonal vaccine effectiveness against influenza A(H3N2) clades and subclades, I-MOVE/I-MOVE+ primary care multicenter study, Europe, influenza seasons 2016–17 and 2017–18.
| Season | Clade/subclade | N | Cases; vacc /Controls; vacc | Adjusted VE (%) | CI (%) |
|---|---|---|---|---|---|
| 2016–17 | 3C.2a (all variants excluding 3C.2a1) | 4492 | 252;28/4240;496 | 31 | −12 to 57 |
| 3C.2a3 N121K+S144K+(N122D+262 N) |
4445 | 205;20/4240;496 | 37 | −9 to 63 | |
| 3C.2a1 (all variants) | 5007 | 767;99/4240;496 | 25 | −1 to 44 | |
| 3C.2a1 (no mutations in A-E antigenic sites other than N171K) | 4454 | 214;19/4240;496 | 56 | 20 to 76 | |
| 3C.2a1b N171K+N121K+K92R+H311Q |
4397 | 157;30/4240;496 | 7 | −56 to 45 | |
| 2017–18 | 3C.2a (all variants) | 3732 | 166;40/3566;445 | −29 | −109 to 21 |
| 3C.2a2 T131K+R142K+R261Q |
3726 | 160;38/3566;445 | −19 | −95 to 27 | |
| 3C.2a1 (all variants) | 3698 | 132;17/3566;445 | 41 | −19 to 71 | |
| 3C.2a1b N171K+N121K+K92R+H311Q |
3697 | 131;17/3566;445 | 42 | −18 to 71 | |
CI: confidence interval; vacc: vaccinated; VE: vaccine effectiveness.