The A11-B15-DR12 haplotype (HLA-A*11:01~B*15:02~DRB1*12:02~DQA1*06:01~DQB1*03:01) was associated with protection from adenovirus 40/41 infection (P-value = 0·017 [Chi-square test], OR = 0·46, 95% CI = 0·22–0·92). This evidence concerns the gene HLA-A and infection.