Fig. 10

Neutralization assay of the hyperimmune sera obtained 30 days post-immunization of BALB/c mice with RBD-P and RBD orally (A) and intramuscularly (B). The y-axis corresponds to the observed percentage of the inhibition of HRP-conjugated RBD interaction with hACE2. Dashed lines represent manufacturers’ cutoff values (30%). The neutralization assay was performed in duplicate for each mouse serum, and per group. C+ is the positive control. Each boxplot presents the mean as an X, the median as the middle line, the interquartile range as box limits, and the 2.5th and 97.5th percentiles as the whiskers. For all variables with the same letter, the difference between the means is not statistically significant. If two variables have different letters, they are significantly different (p < 0.05). When there are two letters in a data set, this is not significantly different from the data sets with those letters