LAIV immunization, (7 log10EID50/ferret)/ Placebo control H5N1 HPAIV challenge virus/PBS load1
A/Vietnam/1194/2004 A/turkey/Turkey/1/2005 PBS
Lungs (D3) Nose (D3) Nasal wash (D3 / D5)3 Lungs (D3) Nose (D3) Nasal wash (D3 / D5) Lungs (D3) Nose (D3) Nasal wash (D3 / D5)
VN/H5N2 LAIV 0 1.40 2.80 / 0 nd nd nd 0 0 0
VN/H5N1-RG LAIV 0 1.52 2.88 / 0 nd nd nd 0 0 0
t/T/H5N2 LAIV nd2 nd nd 0 1.45 2.23 / 0 0 0 0
Placebo (PBS) 4.86 5.10 5.96 / 4.84 4.82 4.96 5.80 / 4.53 0 0 0
1Virus load expressed in log10 PFU/g for lung and nasal turbinates supernatants or log10 PFU/ml for nasal washes;
2nd - not done, challenge with heterogeneous H5N1-HPAIV was not performed;
3D3, D5 - day post-infection with challenged H5N1-HPAIV or placebo inoculation.
Table 9: Virus isolation from respiratory tract of ferrets immunized with H5-LAIV candidates after challenge with H5N1 HPAIV.