Master of Science / The hepatitis B virus (HBV) vaccine has contributed greatly to decreasing the HBV epidemic. However, it remains unclear why 5-10% of individuals do not mount an adequate antibody response. Previous studies have shown that genetic variation influences HBV vaccine response. Since such studies are lacking in South African individuals, we examined the associations between HBV vaccine response and genetic variation in HLA-DPB1, additional candidate genes and HLA-DPB1 expression levels in a South African cohort. HLA-DPA1 and -DPB1 allele typing was performed using Luminex technology, twenty-four candidate SNPs were typed by MassArray Analysis and HLA-DPB1 mRNA expression levels were measured by qPCR. HLA-DPB1*01:01, *04:01:01G and *09:01 and SNPs and haplotypes in IL1B, IL4, IL12B, IFNG and the HLA region were significantly associated with HBV vaccine response. A trend of lower HLA-DPB1 expression associating with better anti-HBs response was observed, although this was not significant. Response to the HBV vaccine is multi-genic but HLA-DP plays an important role. / CR2017