Live attenuated HIV as a vaccine for AIDS: pros and cons
Abstract Anti-HIV-1 vaccines must be safe and effective. In macaques, live attenuated simian immunodeficiency viruses have provided the best protection to date. Similar results were obtained earlier in murine leukemia virus systems in which protection correlated with cellular immunity but not with neutralizing antibodies. Attenuated primate lentiviruses tested thus far have been replication-impaired but may still harbor genetic determinants encoding virulence. Other safety issues concern insertional oncogenesis, genetic instability, vertical transmission and differential pathogenicity in adults and newborns, and viral persistence with possible reactivation during intercurrent illness. Long term safety studies are needed to assess the risks associated with live attenuated retrovirus vaccines.