Transmission of the 2009 pandemic H1N1 virus in the presence of immunity in ferrets

We evaluated if immunity induced via vaccination or infection against hemagglutinin (HA) and/or neuraminidase (NA) could block airborne transmission for the 2009 pandemic H1N1 virus in ferrets. Donor ferrets (DR) with pre-existing immunity to HA, NA, or HA+NA were infected with 2009 pandemic H1N1 and paired with an immunologically naive respiratory contact (RC). Nasal washes were collected from ferrets, and nasal washes with high titers of virus were subjected to whole genome sequencing. H1N1 sequences from ferret nasal washes were evaluated for the emergence of quasi-species and escape variants.