BCR and viral infectious disease: Thus, high level of mutations were commonly seen in the antibody repertoires after virus infection or vaccinations (Laserson et al., 2014; Tan et al., 2014; Wang et al., 2014; Cortina-Ceballos et al., 2015; Wendel et al., 2017), including the BCR repertoires after hepatitis B vaccinations (Galson et al., 2015; Galson et al., 2016).