Research Article

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

Table 2

Clinical observations in ferrets after challenge with B/Brisbane/60/2008 (B/Vic) or B/Phuket/3073/2013 (B/Yam) wild-type influenza virus.

After challenge with B/Vic WT virusBody temperature (°C)Activity (group average)Respiratory symptoms (group average)
Day 21Day 22Day 23Day 24Day 21Day 22Day 23Day 24Day 21Day 22Day 23Day 24

B/Vic LAIV (group 1)38.738.438.838.53.02.02.32.70.00.00.00.0
B/Yam LAIV (group 4)38.838.438.538.23.02.32.32.30.00.71.010.3
Unvaccinated control (group 5)38.939.239.038.53.01.011.712.30.00.70.70.3
Intact animals (group 7)38.538.438.838.43.03.03.03.00.00.00.00.0

After challenge with B/Yam WT virusBody temperature (°C)Activity (group average)Respiratory symptoms (group average)
Day 21Day 22Day 23Day 24Day 21Day 22Day 23Day 24Day 21Day 22Day 23Day 24

B/Yam LAIV (group 3)38.738.639.038.63.02.32.33.020.00.70.70.0
B/Vic LAIV (group 2)38.738.338.238.73.01.711.712.30.00.70.30.0
Unvaccinated control (group 6)38.839.139.238.83.01.311.712.010.01.011.010.7
Intact animals (group 7)38.538.438.838.43.03.03.03.00.00.00.00.0

Statistically significant differences: 1Dunnett test, p≤0.05 (versus intact group); 2Dunnett test, p≤0.05 (vaccinated animals versus unvaccinated control).