Variations in the human leukocyte antigen (HLA) gene appear to be related to outcomes after receipt of an HIV vaccine that was previously shown to protect some individuals from the virus but not others, according to a study by researchers from the United States and Thailand (Prentice HA et al. Sci Transl Med. 2015;7:296ra112).
In 2009, a phase 3 clinical trial of the RV144 HIV-1 vaccine reported an estimated vaccine efficacy of 31.2% (Rerks-Ngarm S et al. N Engl J Med. 2009;361:2209-2220). In a follow-up study in 2012, researchers determined that 2 different antibody responses may explain why some vaccine recipients were protected and others were not: high levels of immunoglobulin G (IgG) antibodies specific to a region of the outer HIV envelope correlated with lower infection rates, while high levels of IgA antibodies specific to the HIV envelope were associated with increased risk of infection (Haynes BF et al. N Engl J Med. 2012;366:1275-1286).
Friedrich MJ. Outcomes of HIV Vaccine Related to Genetic Variation. JAMA. 2015;314(11):1107. doi:10.1001/jama.2015.10553