A Medical Accident?

New speculation links polio vaccine to the birth of AIDS

Devastated by outbreaks of paralytic polio, the people of the Belgian Congo (now Zaire) had every reason to be thankful in 1957, when they became the first large group to receive an experimental polio vaccine. Ironically, the quest for deliverance from this ancient scourge may have made them unwitting participants in the birth of a new plague -- AIDS. That, at least, is the contention of a speculative but intriguing article in Rolling Stone.

The oral vaccine, developed by Dr. Hilary Koprowski of Philadelphia's Wistar Institute, was made from weakened polio viruses grown in a culture of monkey kidney cells. Several...