HIV Subtypes, Antigenic Diversity, and Vaccine Design
Bette T. Korber, Catherine C. Miller, and Thomas K. Leitner
from: AIDS Vaccine Development: Challenges and Opportunities (Edited by: Wayne Koff, Patricia Kahn and Ian D. Gust). Caister Academic Press, U.K. (2007)
Abstract
The variation of HIV-1 on the individual level, between individuals, and between different subtypes is considered a major obstacle in HIV-1 vaccine design. HIV-1 subtypes, or clades, are clearly distinguishable genetic classifications of HIV. Recombination is an inherent aspect of HIV evolution, and inter-subtype recombinant forms are frequently found in regions of the world where multiple forms are co-circulating. Vaccine reagents, to be useful, must elicit immune responses that are cross-reactive in the context of this complex backdrop of diverse strains. There are no clear and general genotype-serotype relationships between sequences and neutralizing antibodies. T-lymphocyte responses to HIV cover the spectrum from subtype-specific, to diminished but detectable inter-clade responses, to broadly cross-reactive. While the relative merits of developing HIV-1 subtype-specific vaccines for different proteins are as yet unresolved, given the polyclonal and host specific nature of the immune response, regional subtype appropriate vaccines may be helpful for maximizing the set of potential cross-reactive responses between vaccine strains and the circulating population. Different strategies for vaccine design that attempt to contend with diversity are discussed read more ...
