Table 3.
Association between hemagglutinin inhibition (HI) and microneutralization titers (MNT) before the first pandemic wave (June 2009) and cumulative incidences of infection
| Yes | % | No | Total | P‐value | Yes | % | No | Total | P‐value | |
|---|---|---|---|---|---|---|---|---|---|---|
| HI titer | Cumulative incidence by HI | Cumulative incidence by both HI and MNT | ||||||||
| <10 | 15 | 32·6 | 31 | 46 | <0·005 | 14 | 30·4 | 32 | 46 | <0·05 |
| 10 | 45 | 40·2 | 67 | 112 | 37 | 33·0 | 75 | 112 | ||
| 20 | 15 | 17·4 | 71 | 86 | 14 | 16·3 | 72 | 86 | ||
| 40 | 1 | 5·6 | 17 | 18 | 1 | 5·6 | 17 | 18 | ||
| 80 | 0 | 0·0 | 2 | 2 | 0 | 0·0 | 2 | 2 | ||
| <40 | 75 | 30·7 | 169 | 244 | <0·05 | 65 | 26·6 | 179 | 244 | <0·05 |
| ≥40 | 1 | 5·0 | 19 | 20 | 1 | 5·0 | 19 | 20 | ||
| Total | 76 | 28·8 | 188 | 264 | 66 | 25·0 | 198 | 264 | ||
| MNT titer | Cumulative incidence by MNT | Cumulative incidence by both HI and MNT | ||||||||
| <20 | 86 | 36·3 | 151 | 237 | 0·52 | 60 | 25·3 | 177 | 237 | 0·44 |
| 20 | 4 | 30·8 | 9 | 13 | 4 | 30·8 | 9 | 13 | ||
| 40 | 2 | 16·7 | 10 | 12 | 1 | 8·3 | 11 | 12 | ||
| 80 | 1 | 50·0 | 1 | 2 | 1 | 50·0 | 1 | 2 | ||
| <40 | 90 | 36·0 | 160 | 250 | 0·27 | 64 | 25·6 | 186 | 250 | 0·34 |
| ≥40 | 3 | 21·4 | 11 | 14 | 2 | 14·3 | 12 | 14 | ||
| Total | 93 | 35·2 | 171 | 264 | 66 | 25·0 | 198 | 264 | ||