Mystery Of The Monkey Virus How Could SV40 Have Infected Humans, And What Are The Potential Consequences? By Kevin Newman (ABCNEWS.com) Scientists have detected the SV40 virus, which is known to cause cancer in rodents, in human tumors. March 12 - It is a mystery with enormous implications that has stumped some of the smartest minds in cancer research: How did a cancer-causing monkey virus end up in human tumors? If it is indeed in humans, its role in causing human cancers is unknown. Scientists say it may play a key part - or possibly no part at all. The puzzle began in 1994, when Dr. Michele Carbone, a Loyola University researcher, found the virus SV40, which had never before been detected in humans, in half of the human lung tumors he was studying. SV40 is known to create tumors in animals, but how it might have gotten into humans was unclear. "I thought there must be something wrong. I must have made a mistake," he said, remembering the discovery. Eventually, 60 different lab studies confirmed the results. "This finding has been replicated in New Zealand, in China, in Britain, in France, in Switzerland, in Belgium," Carbone said. Several labs did not find any evidence of SV40, and some researchers continue to question Carbone's findings. Efforts in general to explain the SV40 mystery have been hampered by unusual acrimony among those studying the problem. Could It Have Been Transmitted By Polio Vaccine? If the monkey virus SV40 is indeed in humans, there are several possible explanations for how it got there, says Janet Butel, a virologist at Baylor College of Medicine and one of America's leading virus researchers. "One is that it has always been there in humans, and no one has detected it in the past," Butel said. There is another, much more controversial theory as well, however. Some researchers contend SV40 was transmitted to humans through the polio vaccine, which has saved many lives. The vaccine is made in monkey kidney cells, and from 1955 to 1963 an estimated 20 million Americans were given doses contaminated with SV40. Still, the virus was not detected in humans until Carbone's 1994 research, possibly because no one had thought to look for it. In 1961, the Food and Drug Administration ordered the vaccine's manufacturers to screen out the SV40, which they say they did. But a lawyer involved in a recent polio case has just published a report claiming contamination continued. "In certain instances, no [SV40] tests were ever performed," the lawyer, Stan Kops, wrote about one of the vaccine's manufacturers, Lederle. 'Every Batch Was Screened,' Insists Vaccine Maker Lederle strongly disputes Kops' claim, telling ABCNEWS in a statement "every batch of the polio virus used to manufacture vaccine underwent tissue culture testing for SV40." If that is true, it suggests another possible reason SV40 has been found in the brain tumors of people born after 1963: transmission from mother to child. "I think studies need to be done to figure out precisely what the role of the virus might be in human cancer," said Butel. Scientists specializing in SV40 met today in Bethesda, Md., to sort through some of the controversies. Some still question whether SV40 truly exists in humans, but the vast majority of scientists attending the conference believe the role of SV40 in humans needs urgent attention. "We need to find out what it's doing there," said Butel. "It will be a great significance if it's proven to have a role in human cancer because then . it may be possible to block infection and the formation of a tumor." There may be several viruses linked to cancer in humans. ABCNEWS' Nicholas Regush, whose column Second Opinion appears weekly on ABCNEWS.com, produced this report. ------------------------------------------------------------------- Dawn Richardson PROVE(Parents Requesting Open Vaccine Education) prove@vaccineinfo.net (email) http://vaccineinfo.net/ (web site) ------------------------------------------------------------------- PROVE provides information on vaccines, and immunization policies and practices that affect the children and adults of Texas. Our mission is to prevent vaccine injury and death and to promote and protect the right of every person to make informed independent vaccination decisions for themselves and their family. ------------------------------------------------------------------- This information is not to be construed as medical OR legal advice. ------------------------------------------------------------------- Subscribe to PROVE Email Updates: Click here http://vaccineinfo.net//subscribe.htm