HIV Inter-subtype Recombination -Consequences for the Epidemic

Until just a few years ago, HIV-1 was believed to evolve primarily by accumulating point mutations, leading to gradual rather than abrupt changes in virological properties. More extensive sampling and development of new laboratory and data-analysis methods have revealed that this picture was incomplete. HIV-1 has in recent years been shown to use recombination as an additional mechanism for the generation of variation and diversity. As data continues to accumulate, the role of recombination for viral evolution, and indeed the evolution of the global epidemic, has become increasingly evident. Factoring in recombination between divergent HIV strains and especially between different subtypes has brought about changes, not only in the genetic HIV-1 classification system, but also in the ways we must think about developing vaccine and prevention strategies. The continuous dissemination of different HIV-1 subtypes throughout the world will lead to multiple opportunities for intersubtype recombination, of which the consequences will be discussed below.