Recent years have witnessed a growing interest in a field of vaccinology that we have named vaccinomics. The overall idea behind vaccinomics is to identify genetic and other mechanisms and pathways that determine immune responses, and thereby provide new candidate vaccine approaches. Considerable data show that host genetic polymorphisms act as important determinants of innate and adaptive immunity to vaccines. This review highlights examples of the role of immunogenetics and immunogenomics in understanding immune responses to vaccination, which are highly variable across the population. The influence of HLA genes, non-HLA, and innate genes in inter-individual variations in immune responses to viral vaccines are examined using population-based gene/SNP association studies. The ability to understand relationships between immune response gene variants and vaccine-specific immunity may assist in designing new vaccines. At the same time, application of state-of-the-art next-generation sequencing technology (and bioinformatics) is desired to provide new genetic information and its relationship to the immune response.