Figure 9.

Neutralising anti-VP2 antibody titres in T cell- or mock-depleted sheep during bluetongue virus (BTV) infection. Neutralising antibody titres in CD4⁺ (purple, n = 7), CD8⁺ (green, n = 7), or WC1⁺ (blue, n = 7) T cell- and mock-depleted (red, n = 7) sheep during infection with BTV-4 MOR2009/07 as determined by immunofluorescence-based serum neutralisation test when assessing antibodies with (A) fully neutralising activity (absence of BTV infection/fully protected cells across the monolayer) and (B) fully and partially neutralising activity (with partially neutralising activity defined as wells with less than 20% BTV infection remaining in the cell monolayer compared to 50%–100% infection in the positive control). Dots represent anti-VP2 antibody titres of individual animals, with bars representing the mean and error bars representing standard deviation. Dotted lines represent designated cut-offs, above which signify anti-VP2 antibody-positive sera. The number of animals alive over the course of infection is designated above arrows at the top of each plot.