H5N1-specific B cells were detected in ferrets infected with live attenuated H5N1 <i>ca</i> vaccines.

<p>Ferrets were intranasally administered the H5N1 VN04 <i>ca</i> or HK03 <i>ca</i> viruses on day 0. Five and ten days post-inoculation, ferrets were sacrificed to collect paratracheal lymph nodes (TLN) and a B cell ELISpot assay was performed using lymphocytes isolated from TLN and BPL-inactivated H5N1 HK03 <i>ca</i> virus or rH5 HA antigens. The number of IgM ASC (A) and IgG ASC (B) are presented as per 10⁶ lymphocytes.