Clinical signs, virus replication, seroconversion, and transmission in ferrets inoculated with H2N2 viruses.

RD, respiratory droplet; DC, direct contact transmission; ND, not determined.
πThis experiment was performed using virus that was obtained from plaque purification and grown in MDCK cells.
¶These experiments were done independently from the first one, using virus that was grown in allantoic fluid of 10-day old embryonated eggs.
*The percentage corresponds to the ferrets that exhibited highest drop in weight during the experiment.
** Hemagglutination inhibition (HI) titer is shown. Performed with homologous virus and turkey red blood cells.
*** The lack of seroconversion in one of the ferrets is explained by the short window span between late peak of virus detection and sera sample collection.