POLIO VACCINES AND THE ORIGIN OF AIDS

Although mass vaccination programs have resulted in the eradication of a number of human infectious diseases, vaccine contamination has been a persistent concern. In particular, it is now known that the early p olio vaccines were contaminated with at least one monkey virus, SV40. The transfer of monkey viruses to man via contaminated vaccines is par ticularly relevant to the acquired immunodeficiency syndrome (AIDS), s ince the causative agent of AIDS, human immunodeficiency virus (HIV), is thought to be derived from a simian precursor virus. Furthermore, h uman infection with this virus appears to be a relatively recent event . We hypothesize that the AIDS pandemic may have originated with a con taminated polio vaccine that was administered to inhabitants of Equato rial Africa from 1957 to 1959. The mechanism of evolution of HIV from this vaccine remains to be determined.