Table 4.
Titers of Ck/Qal-Egypt/1/08 (H5N1) virus in chickens immunized passively with H5 antibodies before vaccination with the YEBIO H5N1 Re-1 vaccine
| i.p. injection with | Virus titers* | |||||
| Trachea | Cloaca | |||||
| 3 dpc | 5 dpc | 7 dpc | 3 dpc | 5 dpc | 7 dpc | |
| PBS | <(0/9)† | <(0/9) | <(0/9) | <(0/9) | <(0/9) | <(0/9) |
| 1:100-diluted sera | <(0/9) | <(0/9) | <(0/9) | <(0/9) | <(0/9) | <(0/9) |
| 1:10-diluted sera | <(0/9) | <(0/9) | <(0/9) | <(0/9) | <(0/9) | <(0/9) |
| Undiluted sera | 3.5 ± 2.3 (2/9) | 4.8 ± 1.9 (2/9) | 4.0 ± 2.0 (3/8) | 3.6 ± 1.4 (2/9) | 5.0 ± 0.7 (2/9) | 3.8 ± 0.0 (1/7) |
| Control‡ | 4.8 ± 1.6 (8/8) | 6.6 ± 0.8 (5/5) | nd | 5.4 ± 1.2 (3/8) | 4.8 ± 0.7 (5/5) | nd |
dpc, days postchallenge; nd, not determined because of death.
aLog10 EID50/mL determined in eggs. Data are the mean ± SD of positive (=0.75 log10 EID50/mL) titers. Values in parentheses are number shedding/number tested.
†<, the titer was below the limit of detection (<0.75 log10 EID50/mL).
‡Chickens were immunized passively with pooled anti-H5 chicken sera but not vaccinated before challenge.