Fig 1.
Test groups of ferrets.
Table 1.
Clinical observations in ferrets vaccinated with trivalent or quadrivalent LAIV and challenged with B/Brisbane/60/2008 (B/Vic) or B/Phuket/3073/2013 (B/Yam) wild-type influenza viruses.
Fig 2.
(a) after vaccination with T-LAIVs, Q-LAIV or PBS; (b) after challenge with WT B/Vic following by vaccination with T-LAIVs, Q-LAIV or PBS; (c) after challenge with WT B/Yam following by vaccination with T-LAIVs, Q-LAIV or PBS. *significantly different from non-vaccinated, non-challenged group (P1: Kruskal-Wallis ANOVA (all groups); P2: Mann-Whitney U test (vs. group 9)).
Table 2.
Isolation of vaccine viruses from nasal washes of ferrets in embryonated chicken eggs on day 3 post vaccination.
Table 3.
Vaccine virus shedding on day 3 and humoral immune response to components of LAIV on day 28 post vaccination, respectively.
Fig 3.
Detection of challenge virus in ferrets.
(a) detection of challenge virus by culturing test samples in embryonated eggs; (b) detection of challenge virus in test samples by quantative RT-PCR. P values (Mann-Whitney U test) are stated. T-LAIV (B/Vic) + WT B/Vic (group 1); T-LAIV (B/Vic) + WT B/Yam (group 2); T-LAIV (B/Yam) + WT B/Vic (group 3); T-LAIV (B/Yam) + WT B/Yam (group 4); Q-LAIV + WT B/Vic (group 5); Q-LAIV + WT B/Yam (group 6); WT B/Vic (control of challenge virus, group 7); WT B/Yam (control of challenge virus, group 8).
Fig 4.
Histological view of the lungs.
Red arrows indicate inflammation; black arrows indicate presence of goblet cells. (a) Bronchus. Alcian blue, H&E x 200; (b). Alveolar tissue. Alcian blue, H&E x 400; (c) Bronchus. Alcian blue, H&E x 200; (d). Alveolar tissue. Alcian blue, H&E x 400.