Table 1 Vaccine program of Broiler GP(Grandparent) and PS(Parents) used in the experiment
| Age of chickenA | Broiler GPS | Age of chicken | Broiler PS |
| Strain of IBVB | Live/killed | Strain of IBV | Live/killed |
| 4 days | KM91C | Live | 1 day | KM91 | Live |
| 3 weeks | KM91 | Live | 3 weeks | KM91 | Live |
| 5 weeks | KM91 | Live | 5 weeks | KM91 | Live |
| 8 weeks | KM91 | Live | 8 weeks | KM91 | Live |
| 15 weeks | KM91 | Live | 15 weeks | KM91 | Live |
| 19 weeks | KM91, Ma5D | Killed | 19 weeks | KM91, Ma5 | Killed |
| 21 weeks | KM91 | Live | 21 weeks | KM91 | Live |
| 23 weeks | KM91 | Live | 26 weeks | KM91 | Live |
| 29 weeks | KM91 | Live | 32 weeks | KM91 | Live |
| 35 weeks | KM91 | Live | 38 weeks | KM91 | Live |
| 41 weeks | KM91 | Live | 44 weeks | KM91 | Live |
| 47 weeks | KM91 | Live | 50 weeks | KM91 | Live |
| 53 weeks | KM91 | Live | | | | |
| 59 weeks | KM91 | Live | | | | |
A Age of chickens: The age of chicken when the samples were collected.
B IBV: Infectious bronchitis virus.
C M91: Infectious bronchitis field serotype circulating in Korea.
D a5: Infectious bronchitis vaccine serotype Massachusetts in worldwide.