Figure 2: Immunogenicity of inactivated polyvalent HRV is related to dose.

Mice (2 groups, 20 per group) were vaccinated with 10-valent HRV vaccine consisting of low inactivated-TCID₅₀ per dose input titres (x-axis), similar to the 1975 Hamory et al. study³³, plus alum (magenta open circles) or with 10-valent HRV vaccine with high inactivated-TCID₅₀ per dose input titres plus alum (blue open squares). Sera were collected 18 days after prime (a) and 18 days after boost (b), pooled for each group and nAb titres (y-axis) were measured against the indicated types in the vaccines. The dashed line represents LOD. Undetectable nAb were assigned LOD/2, and some symbols below LOD were nudged for visualization. Three independent experiments using low input titres showed similar results. There was a statistically significant association between input TCID₅₀ virus titre and a detectable nAb response following prime (P=0.01) and boost (P=0.03) vaccination (Fisher’s exact test).