Cross-Protective Efficacy of Monovalent Live Influenza B Vaccines against Genetically Different Lineages of B/Victoria and B/Yamagata in Ferrets

Table 1

Clinical observations in ferrets after vaccination with monovalent B-LAIV.

Group	B/Vic LAIV (groups 1-2)				B/Yam LAIV (groups 3-4)				Intact animals (group 7)
Day	Day 0	Day 1	Day 2	Day 3	Day 0	Day 1	Day 2	Day 3	Day 0	Day 1	Day 2	Day 3
Body temperature (°C)	38.4	38.3	38.7	38.8	38.7	38.8	38.9	38.8	38.5	38.7	38.6	38.7
Activity [group Median (Q1-Q3)]	3.0 (3.0-3.0)	2.5 (1.0-3.0)	2.5 (1.0-3.0)	3.0 (3.0-3.0)	3.0 (3.0-3.0)	1.5 (0.0-2.0)	2.0 (2.0-2.0)	2.5 (2.0-3.0)	3.0 (3.0-3.0)	3.0 (3.0-3.0)	3.0 (3.0-3.0)	3.0 (3.0-3.0)
Respiratory symptoms [group Median (Q1-Q3)]	0.0 (0.0-0.0)	0.5^1 (0.0-1.0)	0.5^1 (0.0-1.0)	0.5^1 (0.0-1.0)	0.0 (0.0-0.0)	1.0^1 (1.0-1.0)	1.0^1 (1.0-1.0)	1.0^1 (0.0-1.0)	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.0 (0.0-0.0)

Abbreviations are used here and in Tables 2–5 and Figures 1 and 2: B/Yam LAIV, monovalent LAIV based on B/60/Phuket/2013/26 (B/Yamagata lineage); B/Vic LAIV, monovalent LAIV based on B/60/Brisbane/2008/83 (B/Victoria lineage); B/Yam WT, B/Phuket/3073/2013 wild type virus (B/Yamagata lineage); B/Vic WT, B/Brisbane/60/2008 wild-type virus (B/Victoria lineage). Statistically significant differences: ¹median test between groups, p≤0.05, post hoc Dunnett test, p≤0.05 (versus intact group).