Figure 3: Blocking of NoV GII-4 VLP binding to the HBGA receptors by immune mouse sera. Group wise pooled (five mice/ group), two-fold diluted sera of mice immunized by IM or IN route with a NoV vaccine candidate containing 10 μg GII-4 VLPs were assayed for blocking activity. Corresponding control group serum was used as a non-specific blocking control. (A) Blocking of GII-4 VLP binding to human secretor positive saliva type A. (B) Blocking of GII-4 VLP binding to the H-t-3 synthetic HBGA. The blocking index (%) was calculated as 100% - (OD wells with serum/OD wells without serum, a maximum binding) × 100%. Results are shown as the mean blocking index of duplicate wells with similar results from a minimum of two independent experiments.