These findings suggest that polymorphisms in the CD3Z gene might affect the outcome of the immune response to vaccination against hepatitis B. Furthermore, the study suggests that several novel candidate genes outside the HLA region might influence the immunity that is induced by vaccination against hepatitis B. Additional studies that concentrate on the search for new molecules involved in the immune response to hepatitis B vaccination might lead to a better understanding of the mechanism of action of vaccines. This evidence concerns the gene CD247 and hepatitis B virus infection.