All the hype surrounding cloned animals misses the big picture (Voice, Feb. 27). If our goal is to study human illnesses or to produce vaccines, money and time would be better spent working with human cells–not cloning humans but using isolated human cells and cell clusters, which already can be reproduced and kept alive in the laboratory.
Experimenters claim that cloned sheep may someday produce organs for human transplant and human medicines. There is a grave danger that such uses could expose humans to unknown and deadly viruses. As was demonstrated recently, even genetically engineered pigs, bred to be supposedly “germ-free,” harbor potentially deadly viruses that can infect humans. This discovery led United Kingdom health officials to halt proposed animal-to-human transplant experiments.
The shortage of human organs available for transplant can be solved, first, through preventive diet and lifestyle modifications that eliminate the need for most transplants, and, second, by stepping up programs to encourage Americans to sign organ donor cards when they renew their driver’s licenses.
The dangers of animal cells are all too real. Millions of people who received polio vaccines derived from monkey cells in the 1950s were exposed to SV40–a monkey virus that has been directly implicated in triggering cancer. Prior to 1961, SV40 was simply an unknown virus that came along for the ride when monkey cells were used to manufacture the vaccine. An estimated 10 to 30 million people in the U.S. received live SV40 before its discovery. Other unknown viruses almost certainly inhabit current animal-derived vaccines.
If cloned sheep are used to produce human vaccines or medicines, the SV40 scenario may well be repeated. Human cells, of course, behave exactly like their counterparts in a person and can be screened for human viruses, thus nearly eliminating the possibility of unleashing a new viral strain on humankind. Animals are not reliable or suitable “models” for studying human disease and illness, so having one more way to produce them is like finding a great new method to produce a Corvair. No matter how “revolutionary” the production process, what you’re left with is an unsafe and unreliable product.
