Figure 7.

Induction of humoral response by the bivalent EIV LAIV before and after WT viral challenges: Fifty-seven days after prime vaccination, group 1 horses (n = 6) were challenged with 5 × 10⁷ EID₅₀ of the clade 1 KY/14 WT and group 2 horses (n = 6) were challenged with 5 × 10⁷ EID₅₀ of the clade 2 Rich/07 WT. Unvaccinated horses (n = 3) were used as internal controls in each group. HAI titers against Ohio/03 WT (A,D), KY/14 WT (B,E), and Rich/07 WT (C,F) were determined using sera collected before (day 0) and 7, 14, and 21 days after challenge of group 1 (A–C) and group 2 (D–F) horses. Individual HAI titers (log₂) with sera obtained from vaccinated and control horses are represented as black circles and gray squares, respectively. Bars indicate the geometric mean of the results obtained from the vaccinated or control horses, respectively. An HAI titer of 5 (equivalent to HAI log₂ of 0.71) was arbitrarily assigned to those data below the limit of detection (<10). * p < 0.05 was considered statistically significant.