Table 1. Influenza A(H3N2) cases and controls included in the 2016/17 season influenza vaccine effectiveness analysis, I-MOVE/I-MOVE+ multicentre case control studies (primary care (n = 5,023) and hospital (n = 635) levels) Europe, influenza season 2016/17 .
| Variables | Primary care level | Hospital level | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of A(H3N2) n = 2,250 | Number of controls n = 2,773 |
Number of A(H3N2) n = 267 |
Number of controls n = 368 |
|||||||||
| n | Total | % | n | Total | % | n | Total | % | n | Total | % | |
| Median age (years) | 29 | 28 | 79 | 80 | ||||||||
| Age groups (years) | ||||||||||||
| 0–4 | 276 | 2,242 | 12.3 | 723 | 2,766 | 26.1 | NA | NA | ||||
| 5–14 | 508 | 2,242 | 22.7 | 336 | 2,766 | 12.1 | NA | NA | ||||
| 15–64 | 1,177 | 2,242 | 52.5 | 1,438 | 2,766 | 52.0 | NA | NA | ||||
| 65–79 | 234 | 2,242 | 10.4 | 214 | 2,766 | 7.7 | 138 | 267 | 51.7 | 185 | 368 | 50.3 |
| ≥ 80 | 47 | 2,242 | 2.1 | 55 | 2,766 | 2.0 | 129 | 267 | 48.3 | 183 | 368 | 49.7 |
| Missing | 8 | 7 | 0 | 0 | ||||||||
| Sex | ||||||||||||
| Female | 1,126 | 2,237 | 50.3 | 1,407 | 2,758 | 51.0 | 141 | 267 | 52.8 | 190 | 368 | 51.6 |
| Missing | 13 | 15 | 0 | 0 | ||||||||
| Chronic conditions | ||||||||||||
| At least one chronic condition | 451 | 2,237 | 20.2 | 542 | 2,743 | 19.8 | 237 | 255 | 92.9 | 321 | 344 | 93.3 |
| Missing | 13 | 30 | 12 | 24 | ||||||||
| At least one hospitalisation in the previous 12 months for chronic conditions | 26 | 2,196 | 1.2 | 57 | 2,686 | 2.1 | 66 | 247 | 26.7 | 146 | 334 | 43.7 |
| Missing | 54 | 87 | 20 | 34 | ||||||||
| Target group for vaccination | ||||||||||||
| Belongs to a target group for vaccination | 616 | 2,241 | 27.5 | 706 | 2,755 | 25.6 | 267 | 267 | 100.0 | 368 | 368 | 100.0 |
| Missing | 9 | 18 | 0 | 0 | ||||||||
| Swab delay | ||||||||||||
| Swabbed within 3 days of symptom onset | 2,024 | 2,250 | 90.0 | 2,291 | 2,773 | 82.6 | 154 | 267 | 57.7 | 212 | 368 | 57.6 |
| Vaccination status | ||||||||||||
| Seasonal flu vaccination 16–17 | 231 | 2,250 | 10.3 | 301 | 2,773 | 10.9 | 108 | 267 | 40.4 | 191 | 368 | 51.9 |
| Seasonal flu vaccination 15–16 | 223 | 2,196 | 10.2 | 316 | 2,665 | 11.9 | 117 | 252 | 46.4 | 199 | 362 | 55.0 |
| Missing | 54 | 108 | 15 | 6 | ||||||||
| Previous and current season influenza vaccination | ||||||||||||
| Not vaccinated in any season | 1,929 | 2,196 | 87.8 | 2,284 | 2,665 | 85.7 | 128 | 252 | 50.8 | 147 | 362 | 40.6 |
| Current season vaccination only | 44 | 2,196 | 2.0 | 65 | 2,665 | 2.4 | 7 | 252 | 2.8 | 16 | 362 | 4.4 |
| Previous season vaccination only | 43 | 2,196 | 2.0 | 95 | 2,665 | 3.6 | 20 | 252 | 7.9 | 28 | 362 | 7.7 |
| Current and previous season vaccination | 180 | 2,196 | 8.2 | 221 | 2,665 | 8.3 | 97 | 252 | 38.5 | 171 | 362 | 47.2 |
| Missing | 54 | 108 | 15 | 6 | ||||||||
| Type of vaccine | ||||||||||||
| Not vaccinated | 2019 | 2,215 | 91.2 | 2,472 | 2,725 | 90.7 | 159 | 261 | 60.9 | 177 | 359 | 49.3 |
| Inactivated subunit egg | 97 | 2,215 | 4.4 | 108 | 2,725 | 4.0 | 65 | 261 | 24.9 | 101 | 359 | 28.1 |
| Inactivated split virion egg | 71 | 2,215 | 3.2 | 118 | 2,725 | 4.3 | 32 | 261 | 12.3 | 74 | 359 | 20.6 |
| Adjuvanted | 18 | 2,215 | 0.8 | 21 | 2,725 | 0.8 | 5 | 261 | 1.9 | 7 | 359 | 1.9 |
| Quadrivalent vaccine | 10 | 2,215 | 0.5 | 6 | 2,725 | 0.2 | 0 | 261 | 0.0 | 0 | 359 | 0.0 |
| Missing vaccine type | 35 | 48 | 6 | 9 | ||||||||
| Month of onset | ||||||||||||
| October 2016 | 4 | 2,250 | 0.2 | 84 | 2,773 | 3.0 | 0 | 267 | 0.0 | 0 | 368 | 0.0 |
| November 2016 | 154 | 2,250 | 6.8 | 759 | 2,773 | 27.4 | 3 | 267 | 1.1 | 6 | 368 | 1.6 |
| December 2016 | 1,199 | 2,250 | 53.3 | 1,194 | 2,773 | 43.1 | 174 | 267 | 65.2 | 236 | 368 | 64.1 |
| January 2017 | 893 | 2,250 | 39.7 | 736 | 2,773 | 26.5 | 90 | 267 | 33.7 | 126 | 368 | 34.2 |
| Study sites | ||||||||||||
| Croatia | 13 | 2,250 | 0.6 | 13 | 2,773 | 0.5 | NA | NA | ||||
| Finland | NA | NA | 14 | 267 | 5.2 | 17 | 368 | 4.6 | ||||
| France | 584 | 2,250 | 26.0 | 609 | 2,773 | 22.0 | 35 | 267 | 13.1 | 116 | 368 | 31.5 |
| Germany | 28 | 2,250 | 12.8 | 873 | 2,773 | 31.5 | NA | NA | ||||
| Hungary | 39 | 2,250 | 1.7 | 84 | 2,773 | 3.0 | NA | NA | ||||
| Ireland | 135 | 2,250 | 6.0 | 113 | 2,773 | 4.1 | NA | NA | ||||
| Italy | 411 | 2,250 | 18.3 | 367 | 2,773 | 13.2 | 37 | 267 | 13.9 | 58) | 368 | 15.8 |
| Lithuania | NA | NA | 30 | 267 | 11.2 | 18 | 368 | 4.9 | ||||
| Navarra | NA | NA | 20 | 267 | 7.5 | 34 | 368 | 9.2 | ||||
| The Netherlands | 47 | 2,250 | 2.1 | 142 | 2,773 | 5.1 | 6 | 267 | 2.2 | 19 | 368 | 5.2 |
| Poland | 9 | 2,250 | 0.4 | 33 | 2,773 | 1.2 | NA | NA | ||||
| Portugal | 156 | 2,250 | 6.9 | 80 | 2,773 | 2.9 | 36 | 267 | 13.5 | 14 | 368 | 3.8 |
| Romania | 27 | 2,250 | 1.2 | 9 | 2,773 | 0.3 | 60 | 267 | 22.5 | 37 | 368 | 10.1 |
| Spain | 474 | 2,250 | 21.1 | 303 | 2,773 | 10.9 | 29 | 267 | 10.9 | 55 | 368 | 14.9 |
| Sweden | 66 | 2,250 | 2.9 | 147 | 2,773 | 5.3 | NA | NA | ||||
NA: Not applicable.