PPIB and hepatitis A virus infection: Further, primary vaccinations (meningococcus, primary hepatitis B)(Galson et al., 2016; Galson et al., 2015a) showed stronger signatures of measurable evolution than secondary vaccinations (adult seasonal influenza, hepatitis B booster) (Ellebedy et al., 2016; Galson et al., 2015b; Laserson et al., 2014; Turner et al., 2020).