| Number of birds | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
 | Mean HI titer (absolute (sd)) | with HI titer ≥ 2^5 at challenge | shedding virus a | with clincial symptoms | that died | ||||||
Exp. | Treatment | at challenge ( 2 log) | at end d ( 2 log) | I b | C b | I | C | I | C | I | C |
1 | no vaccination challenge at d28 of age | 1.6 (1.0) | 206 (457) | 0 | 0 | 22 | 19 | 22 | 22 | 22 | 16 |
2 | vaccination at d1 challenge at d28 of age | 1.7 (1.3) | 166 (381) | 0 | 0 | 22 | 18 | 19 | 16 | 16 | 15 |
3 | vaccination at d10 challenge at d28 of age | 1.8 (0.9) | 251 (357) | 0 | 0 | 18 | 15 | 16 | 10 | 13 | 7 |
4 | no vaccination challenge at day 1 of age | 4.9 (1.2)c | 1.0 (0.4)f | Ndc | nd | 16 | 6 | 19 | 19 | 13 | 1 |