Partial protection against challenge with the highly pathogenic H5N1 influenza virus isolated in Japan in chickens infected with the H9N2 influenza virus.

摘要: The protective effect of the A/Ck/Yoko/aq55/01 (H9N2) avian influenza virus against highly pathogenic H5N1 virus, i.e., A/Ck/Yama/7/04 (genotype V), was examined. Three 5-week-old chickens were inoculated intranasally with H9N2 (108.6 EID50/head) and kept two contact chickens. All infected reinoculated same at 20 weeks age, 10 days later, they challenged (104.0 EID50/head). Five simultaneously only (challenge control) died within 4 postchallenge (d.p.c.). In contrast, four out five challenged, immune from 5 to 8 d.p.c. median time death in (6.3 days) significantly longer than that challenge controls (3.4 (P < 0.01). No shedding into tracheae feces detected for 3 d.p.c., but H5 genes detectable one chicken by a loop-mediated isothermal amplification method. viruses and/or dead or 1 2 before death. Only survived without any signs 14 gene sporadically trachea 7 respectively. This study shows may have potential induce cross-protection recent lethal V).