V1V2 antibodies protect against infection; Env-specific antibodies reduce protective effect
WEDNESDAY, April 4 (HealthDay News) -- Antibodies to HIV-1 proteins may play a role in the efficacy of HIV-1 vaccination, according to a study published in the April 5 issue of the New England Journal of Medicine.
Barton F. Haynes, M.D., from the Duke University School of Medicine in Durham, N.C., and colleagues conducted a case-control analysis to identify the antibody and cellular immune correlates of infection risk in vaccinees from the RV144 trial. To investigate the roles of T-cell, immunoglobulin (Ig) G, and IgA antibody responses in the modulation of HIV infection risk through 42 months of follow-up, six antibody or cellular assays were performed on 41 vaccinees who became infected and 205 uninfected vaccinees.
The researchers identified two variables significantly associated with infection risk. There was an inverse association between the binding of IgG antibodies to variable regions 1 and 2 (V1V2) of HIV-1 envelope proteins (Env) and the rate of HIV infection (estimated odds ratio, 0.57 per one standard deviation increase). In addition, there was a direct correlation between the binding of plasma IgA antibodies to Env and the rate of infection (estimated odds ratio, 1.54 per one standard deviation increase).
"This immune-correlates study generated the hypotheses that V1V2 antibodies may have contributed to protection against HIV-1 infection, whereas high levels of Env-specific IgA antibodies may have mitigated the effects of protective antibodies," the authors write. "Vaccines that are designed to induce higher levels of V1V2 antibodies and lower levels of Env-specific IgA antibodies than are induced by the RV144 vaccine may have improved efficacy against HIV-1 infection."
Several authors disclosed involvement with patents related to HIV/AIDS vaccination.
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