The upregulated frequencies of CD24+/high CD27+ and CD24highCD38high were found to be reversed in non-responders, together with a lower expression level of IL-10 after receiving a booster dose with a recombinant third-generation vaccine for hepatitis B virus [96], which confirms the assertion by Bolther et al. (2018) [94] that the expression of IL-10-producing Bregs cells is not a good predictor of immunological response to the hepatitis B vaccination. This evidence concerns the gene CD27 and hepatitis A virus infection.