Differential replication of attenuated and virulent influenza viruses in organ cultures of ferret bronchial epithelium. Brief report.

In contrast to its abundant replication in ferret nasal epithelium in vivo and in vitro, comparable to that of the virulent strains, the attenuated influenza virus A/PR/8/34 produced much lower yields than the virulent strains in organ cultures of bronchial epithelium agreeing with its relative inability to infect the lower respiratory tract of ferrets. The replication of another attenuated strain showed different temperature characteristics in bronchial epithelium to that in nasal turbinate epithelium.