Vaccine efficacy among subjects with the FcγRIIIa VV genotype. (A) For subjects with low behavioral risk scores, there is a greater rate of infection among FcγRIIIa VV vaccinees compared with VV placebo recipients (hazard ratio = 4.51; P = .17) or compared with all placebo recipients (hazard ratio = 4.72; P = .002). (B) Among subjects with high behavioral risk scores, VV vaccinees have similar infection rates as VV placebo recipients (hazard ratio = 1.24; P = .64) or all placebo recipients (hazard ratio = 1.27; P = .33).