Table 2.
Serological and virus recovery results post-challenge with ck/CH/LAH/08II and ck/CH/LHB/08I.
| Group a | Vaccinated | Challenged | Dose, median embryo infectious doses (log 10)b | Morbidity | Mortality | Antibodyc |
Virus recoveryd |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days post vaccination |
Days post challenge |
Trachea | Kidney | Lung | Caecal tonsil | |||||||||||||
| 4 | 8 | 12 | 16 | 3 | 6 | 9 | 12 | 16 | ||||||||||
| 1 | Yes | Yes, with ck/CH/LAH/08II | 5.0 | 0/10 | 0/10 | 0/10 | 2/10 | 9/10 | 10/10 | 10/10 | 10/10 | 10/10 | 10/10 | 10/10 | 4/10 | 2/10 | 2/10 | 4/10 |
| 2 | No | Yes, with ck/CH/LAH/08II | 5.0 | 10/10 | 1/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/9 | 9/9 | 9/9 | 9/9 | 8/10 | 4/10 | 5/10 | 8/10 |
| 3 | Yes | Yes, with ck/CH/LHB/08I | 5.0 | 10/10 | 3/10 | 0/10 | 4/10 | 10/10 | 10/10 | 10/10 | 9/9 | 8/8 | 7/7 | 7/7 | 10/10 | 3/10 | 1/10 | 6/10 |
| 4 | No | Yes, with ck/CH/LHB/08I | 5.0 | 10/10 | 7/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 5/9 | 4/5 | 4/4 | 3/3 | 10/10 | 10/10 | 6/10 | 10/10 |
| 5 | No | No | – | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 | 0/10 |
a
Twenty chicks per group.
b
Dose per chick (ck/CH/LAH/08II and ck/CH/LHB/08I), 100 μl.
c
Number seroconverted/number inoculated.
d
Two procedures were used for virus recovery after challenge. First, lesions in embryos that had been inoculated with individual trachea or kidney tissue samples were observed. Second, RT-PCR using oligonucleotide primers N(+) and N(−) on RNA from the allantoic fluid of the same eggs was conducted. The results from the two procedures were identical. Data are number of chicks that showed positive results after challenge/number of chicks that survived after challenge.