Background: The role of human leukocyte antigen (HLA) genes in mediating adaptive immune responses to smallpox vaccine remains unknown.
Methods: We determined genotypes for a group of individuals (n = 1071) who received a single dose of smallpox vaccine (Dryvax, Wyeth Laboratories) and examined associations between HLA alleles and 15 immune outcomes to smallpox vaccine on a per-locus and a per-allele level.
Results: We found significant associations between the HLA-B and HLA - DQB1 loci and vaccinia-induced antibodies (P = .04 for each locus), with the HLA-B*1302 (P = .036), B*3802 (P = .011), DQB1*0302 (P = .015), and DQB1*0604 (P = .017) alleles being associated with higher levels. Significant global associations were identified between vaccinia-specific interferon (IFN)-γ and DQA1 (P = .003), interleukin (IL)-1β and HLA-B (P = .004), tumor necrosis factor (TNF)-α and HLA-B (P = .006), and IL-6 and HLA-B locus (P = .016) for secreted cytokines, as well as between CD8α(+) IFN-γ Elispot responses and DQB1 (P = .027). Subjects carrying B*3906 (P = .006) and B*5701 (P < .001) secreted higher levels of IL-1β than did subjects who did not carry these alleles. Subjects carrying the B*5301 (P = .047) and B*5601 (P = .008) alleles secreted less IL-1β, compared with subjects who did not carry these alleles. The B*3502 (P = .009), B*5601 (P = .004), and B*5701 (P < .001) alleles were significantly associated with variations in TNF-α secretion.
Conclusions: These data suggest that variations in antibody and cellular IFN-γ, IL-1β, TNF-α, and IL-6 immune responses after receipt of smallpox vaccine are genetically controlled by HLA genes or genes in close linkage disequilibrium to these alleles.