Replication and transmission of CA04/09 Ile219->Lys HA mutant virus in ferrets.

aRD, respiratory droplet.bThis experiment was performed using virus that was obtained from plaque purification and grown in MDCK cells.cThe percentage mean maximum weight loss observed during the first 10 days post-inoculation.dNumber of animals positive for infectious virus. Virus titers are expressed as mean log10 peak PFU/mL.eNumber of animals in which sneezing was observed during the first 10 days after inoculation (sneezing was infrequent for all infected animals tested).fHemagglutination inhibition (HI) assay was performed with homologous virus and turkey red blood cells. No. of positive animals and HI range indicated.