Hofstad M S
Avian Dis. 1981 Jul-Sep;25(3):650-4.
Groups of 75 chickens were each infected with one of 7 isolates of infectious bronchitis virus (Mass 41, Holland 52, SE 17, Ark 99, Clark 333, JMK, and Florida). Following recovery, they were challenged along with susceptible controls to the homologous and 6 heterologous isolates. Cross-immunity was determined by virus recovery 4 or 5 days post-challenge. Challenge with the homologous isolate resulted in 90-100% protection. Challenge with heterologous isolates gave variable results and an overall average resistance of 38%. The SE-17-recovered chickens had a 50% protection, whereas the Holland-52-recovered chickens ahd a 13.3% protection.
将75只鸡分为一组，分别用7种传染性支气管炎病毒毒株（Mass 41、Holland 52、SE 17、Ark 99、Clark 333、JMK和Florida）中的一种进行感染。康复后，将它们与易感对照一起用同源毒株和6种异源毒株进行攻毒。通过攻毒后4或5天的病毒回收情况来确定交叉免疫。用同源毒株攻毒可产生90 - 100%的保护作用。用异源毒株攻毒则产生不同的结果，总体平均抵抗力为38%。从感染SE - 17毒株中康复的鸡有50%的保护率，而从感染Holland - 52毒株中康复的鸡有13.3%的保护率。
