Progress and obstacles in the development of an AIDS vaccine

With five million new infections with HIV-1 occurring each year, the development of an effective vaccine against HIV-1 remains an absolute priority.Because of the rapid generation of mutant viruses, HIV-1 exists as a swarm or viral quasi-species, even in a single infected individual.Immune containment of HIV-1 is mediated predominantly by cellular rather than humoral immune responses. It is probable that both mucosal and systemic immune responses will be required for a vaccine to be effective.Vaccine strategies can only be evaluated in non-human primate models.Before an effective vaccine can be generated, there are various problems that must be overcome. For example, a means of generating broadly neutralizing antibodies, and of inducing mucosal immune responses, is needed. A way to deal with the extraordinary genetic diversity of the virus must also be found, as must some means of eliciting durable, potent immune responses.